@article {7447, title = {Towards Automated Compilation of Electronic Navigational Charts: Automated Nautical-Chart Generalization Model}, year = {Submitted}, month = {May 2022}, author = {Tamer Nada and Christos Kastrisios and Brian R Calder and Ence Christie and Craig Greene and Amber Bethell} } @article {7367, title = {Aggregation Methods Using Bathymetry Sources of Differing Subjective Reliabilities for Navigation Mapping}, volume = {46}, year = {2023}, month = {6 February 2023}, pages = {99-128}, publisher = {Taylor and Francis}, abstract = {

When planning for ship navigation or compiling data for a bathymetry map, the navigator or mapper uses many different sources of bathymetry information and navigation hazards. The quality of these sources is inconsistent in general, however, making it challenging to provide a coherent picture for planning. Here, we describe an approach for consistent planning/mapping that uses a combination of soft computing and Bayesian estimation. The case study used to exercise this system involves NOAA Electronic Nautical Charts for an area in the Chesapeake Bay. We first interpolate each set of irregularly spaced soundings to gridded versions of each point-cloud set. Each of these intermediate grids is then aggregated into a fused bathymetric realization using order weighted averaging (OWA) to provide the weights for each source based on their subjective reliabilities. The OWA allows for fusion informed by the user\’s subjective risk allowed in the reconstruction of the seafloor surface and provides quantitative methods to generate, use, and record subjective reliability weights. Each sounding point that went into the bathymetry estimate is then categorized as \“no-go,\” \“caution,\” or \“go\” status. Reliability estimates are reused for weighted Bayesian categorization of each output grid cell to compute the navigable surface.

}, keywords = {Bathymetry Fusion, Bayesian Categorical Estimation, Navigation Risk, Order Weighted Average}, doi = {10.1080/01490419.2023.2166173}, author = {Paul A. Elmore and Brian R Calder and Fred Petry and Giuseppe Masetti and Ron Yager} } @article {7387, title = {An Automated Nautical Chart Generalization Model}, year = {2023}, month = {March 13-17}, pages = {Mobile, AL}, abstract = {

Nautical chart generalization is a tedious task and one of the most challenging and time consuming process in any Hydrographic Office (HO). Significant amounts of labor-intensive effort and time are needed for compiling, generalizing and maintaining those products (e.g., Electronic Navigation Charts \‘ENCs\’). Accordingly, nowadays, one of the main objectives in many HOs is using automated generalization to achieve a perfect compromise for ENCs compilation in a cost-effective manner. However, regardless of the various relevant research efforts and the advancements in technology, generalization tasks are still performed mostly manually or semi-manually, where a likelihood of human error is admitted. Therefore, the ideal situation that would increase efficiency of data production at multiple scales and enable customized data products, is a fully automated generalization solution. \ Such a solution would minimize the time and effort needed for ENC production and support rapid chart updates. In addition, it would solve many compilation problems by generating products on demand, at the right scale, at the point of use, and directly from the best available data respecting the main nautical chart constraints (i.e., Topology, Safety). For instance, since most available ENCs were originally compiled directly from the existing paper charts with digitization, following their traditional overlapping limits, inconsistency between adjacent ENCs are most likely encountered at the cells boundaries. These inconsistencies might affect the performance of the Electronic Chart Display Information System (ECDIS) that uses the data for analyses to the safety of the vessels underway. Thus, an automated generalization solution would significantly save time, and instead, HOs efforts can be steered toward compiling the largest scale cells with harmonizing data on the boundaries.

Towards this optimum goal, we present a research that aims to translate cartographic practice and theory into algorithmic building blocks that can iterate and cooperate to find the appropriate chart representation for any given area, at any scale, optimized according to set criteria. First of all, previous efforts for automated map production were investigated, and available nautical cartographic specifications were comprehensively reviewed. Secondly, generalization guidelines were extracted, categorized and translated into rules to be defined in a template as conditions to be respected during the generalization process. Lastly, an automated nautical generalization (AGN) model was developed to form a comprehensive process that utilizes; the generated template, as the input that derives the data generalization for any desired output scale, the source data, within the areas of interest, to perform the generalization to the target scale respecting topology constraints. However, since safety constraints cannot be ignored, a validation tool was developed that is capable of detecting all the safety violation spots in the output database.\ 

}, keywords = {automated cartography, ENCs, Nautical chart constraints, nautical chart generalization, safety of navigation}, author = {Tamer Nada and Christos Kastrisios and Brian R Calder and Ence Christie and Craig Greene and Amber Bethell} } @article {7366, title = {Design of a Wireless, Inexpensive Ocean of Things System for Volunteer Bathymetry}, year = {2023}, publisher = {IEEE}, abstract = {

Although much progress has been made in recent years to fully map the world ocean, only approximately 20\% is adequately mapped to modern standards. Filling in the remain- der must by necessity be a multi-modal effort, with traditional ocean mapping technologies such as crewed survey ships with multibeam echosounders being mixed with newer systems such as uncrewed, sail-powered mapping systems. Volunteer data from any ship with an echosounder can also be used, but although there have been commercial efforts in this field, most of these systems do not contribute data into the public arena and public entities have largely avoided this field due to complexities of costs, data processing, and uncertainty on how to handle the effort. This paper describes the design of an end-to-end system for managed volunteer bathymetric collection consisting of an inexpensive (\∼$20) wireless \“ocean of things\” data logger for NMEA0183 and NMEA2000 data, associated firmware to manage the collection, a mobile device application to off-load, aggregate, and transfer the data into the cloud, and a cloud segment to process the data and submit it to an international data repository. All of the design has been released under an Open Hardware or Open Source license, allowing independent organizations to initiate data collection efforts without having to do any of the design work themselves. The goal is to provide a simple, approachable\ implementation, encouraging greater adoption of these ideas in hard-to-reach areas of the world with minimal effort on the part of the host organization.

}, keywords = {Cloud-enabled Data Processing, Crowdsourced Bathymetry, Internet of Things, Ocean of Things, Volunteer Bathymetric Information}, doi = {10.1109/JIOT.2023.3234500}, url = {https://ieeexplore.ieee.org/document/10007655}, author = {Brian R Calder} } @proceedings {7389, title = {Towards Automated Nautical Chart Compilation and Verification of Output Topology and Safety}, year = {2023}, month = {August 13-18}, publisher = {International Cartographic Association (ICA)}, address = {Cape Town, South Africa}, abstract = {

The compilation of Electronic Navigational Charts (ENCs) requires significant amount of time, labor-intensive efforts, and cost. Despite the advancements in technology and the various research efforts, generalization tasks are still performed manually or semi-manually with expected human errors. The dramatic increase in the amount of data that is collected by modern acquisition systems, in addition to the increasing timeline expected by the end-users, are constantly driving Hydrographic Offices (HOs) toward the investigation and adoption of more advanced and effective ways for automating the generalization tasks to speed up the process, minimize the cost, and improve productivity. Full automation of the nautical chart compilation process has been unreachable due to the strict nautical cartographic constraints (and particularly those of safety and topology) that pose a challenge for most of the available generalization tools, while it remains questionable whether automation can replace human thought processes. In this paper, we discuss a research effort for an Automated Nautical Generalization (ANG) model in the Esri environment. The ANG model builds upon the nautical chart generalization guidelines and practice and utilizes available tools in the Esri environment to perform the generalization of selected ENC features to the target scale. Safety constraints in\ the marine domain is of utmost importance, however, since most of the readily available tools do not respect safety, the main goal of this effort has been an output with no topological violations. In the current phase of the project, we evaluate safety of soundings and contour for user fixing and while the validation of bathymetry is a well-researched topic, there was the need for an automated process to identify the sections of the generalized contours that have been displaced toward the shallow water side Therefore, this work also presents a safety validation tool that detects the contours\’ safety violations in the output. The tool is composed of three main stages that run individually after the ANG model is complete with the aim to highlight the safety violations for fixing by cartographers

}, keywords = {automated cartography, ENCs, Nautical chart constraints, nautical chart generalization, safety of navigation}, doi = {10.5194/ica-proc-5-14-2023}, author = {Tamer Nada and Christos Kastrisios and Brian R Calder and Ence Christie and Craig Greene and Amber Bethell} } @article {7277, title = {A Geographically Adaptive Model for Satellite Derived Bathymetry}, year = {2022}, month = {June 6-9}, pages = {Ottawa, Canada}, abstract = {
Airborne lidar bathymetry (ALB) and multi-beam echo-sounders (MBES) are two commonly used methods employed by the hydrographic community for bathymetric data collection. Although these technologies can collect high resolution and accurate depth data, they present some limitations related to whether, cost, time, and survey difficulties in near-shore environments. Satellite Derived Bathymetry (SDB) is a relatively new promising technique that utilizes optical satellite remote sensing sensors for estimating bathymetry in shallow water areas. The practice in previous works is with considering a linear relationship between calibrations points and the SDB model, assuming null water column and constant bottom type returns, while a single global bathymetric model is calibrated for the entire scene. To address areas where these assumptions fail and non-uniform water column or bottom conditions can affect the performance of conventional global models, this work presents a vertically and horizontally adaptive model to improve bottom depth estimation. With a case study in Dry-Tortugas, Florida and utilizing Sentinel-2A image, lidar, and chart data in depths up to 30m, we demonstrate the ability of a locally calibrated, piecewise linear function, in providing improved bathymetric estimates compared to conventional techniques. The improved accuracy of the bathymetric estimates with the presented geographically adapted model can enhance the use of satellite derived bathymetry for nautical chart purposes. Figure: Workflow for deriving bathymetry using geographically adaptive model.

}, keywords = {CATZOC, ENC, Nautical cartography, sdb}, url = {https://www.researchgate.net/publication/361307070_A_geographically_adaptive_model_for_satellite_derived_bathymetry}, author = {Juliane Affonso and Christos Kastrisios and Parrish Christopher and Brian R Calder} } @article {7283, title = {The Nautical Cartographic Constraints and an Automated Generalization Model}, year = {2022}, month = {June 6-9}, pages = {Ottawa, Canada}, abstract = {
Current methods for nautical charts generalization are strongly human interactive and time-consuming. Significant amounts of effort are needed for generalizing, compiling, updating, maintaining, and consistency checking those products. The ideal situation would be a fully automated solution for generating products on demand, at the right scale, at the point of use, and directly from the seamless database, that respect all application specific constraints (i.e., Safety, Legibility, Topology, and Morphology). Such a solution would solve many related problems, minimize the time and effort needed for ENC production and support rapid update. However, regardless of the advancements in technology and the various research efforts, generalization tasks for nautical chart compilation are still performed mostly manually or semi-manually, where a likelihood of human error must be admitted. Furthermore, practice has shown that there is often a trade off among the various generalization constraints as fixing one violation may result in the violation of another constraint. Towards this optimum goal, we are conducting a project that aims to investigate the previous efforts for automated map production, review the available relevant nautical cartographic standards and specifications, and extract and categorize the nautical chart generalization guidelines thereinto. These are subsequently translated into rules and defined in a template as conditions to be respected during the generalization process. According to a hierarchy level, a cost will be related to any violation according to its importance to the safety of navigation. Since fully satisfying all constraints seems infeasible, the optimal generalized chart should be the one with the lowest cost. For the implementation, a multi-agent generalization model is under development in the ESRI nautical environment that will utilize the template and the source data within the areas of interest to perform the generalization for the target scale (Figure). Figure: The concept of the nautical generalization model

}, keywords = {automated cartography, computer assisted cartography, ENC, Nautical cartography}, url = {https://www.researchgate.net/publication/361189789_The_Nautical_Cartographic_Constraints_and_an_Automated_Generalization_Model}, author = {Tamer Nada and Christos Kastrisios and Brian R Calder and Ence Christie and Craig Greene and Amber Bethell and Madhu Hosuru} } @article {7364, title = {Operational Performance of a Combined Density- and Clustering-based Approach to Extract Bathymetry Returns from LiDAR Point Clouds}, volume = {107}, year = {2022}, month = {March}, pages = {102699}, abstract = {

An algorithm that combines a widely used sonar data processing method and a newly developed machine-learning-based algorithm to extract of shallow-water bathymetry from LiDAR point clouds was evaluated for accuracy and potential operationalisation. Data comprised 103 500 m-by-500 m data tiles located near the Florida Keys (United States) representing an operationally realistic range of environmental and data conditions. Tiles are processed tiles individually to classify each LiDAR pulse return (\“sounding\” in hydrographic terminology) as bathymetry or not.\  Compared to a reference classification an average agreement of about 90\% was produced; accuracy varied depending on ocean bottom and data conditions.\  The average false negative rate \– the most important metric in hydrographic mapping \– was about 5\%. Processing time for tiles containing the average number of soundings (seven million) on a desktop computer was approximately 100 minutes. A major advantage is that the algorithm does not require in situ ground-\“truth\” data for training or calibration.

}, keywords = {coral reefs, Florida Keys, k-means clustering, Machine Learning, shallow water bathymetry}, doi = {https://doi.org/10.1016/j.jag.2022.102699}, author = {Kim Lowell and Brian R Calder} } @article {7027, title = {Assessing Marginal Shallow-Water Bathymetric Information Content of Lidar Sounding Attribute Data and Derived Seafloor Geomorphometry}, volume = {13(9), 1604}, year = {2021}, month = {April 21}, publisher = {MDPI}, abstract = {

Shallow-water depth estimates from airborne lidar data might be improved by using\ sounding attribute data (SAD) and ocean geomorphometry derived from lidar soundings. Moreover,\ an accurate derivation of geomorphometry would be beneficial to other applications. The SAD\ examined here included routinely collected variables such as sounding intensity and fore/aft scan\ direction. Ocean-floor geomorphometry was described by slope, orientation, and pulse orthogonality\ that were derived from the depth estimates of bathymetry soundings using spatial extrapolation\ and interpolation. Four data case studies (CSs) located near Key West, Florida (United States)\ were the testbed for this study. To identify bathymetry soundings in lidar point clouds, extreme\ gradient boosting (XGB) models were fitted for all seven possible combinations of three variable\ suites\—SAD, derived geomorphometry, and sounding depth. R2 values for the best models were\ between 0.6 and 0.99, and global accuracy values were between 85\% and 95\%. Lidar depth alone\ had the strongest relationship to bathymetry for all but the shallowest CS, but the SAD provided\ demonstrable model improvements for all CSs. The derived geomorphometry variables contained\ little bathymetric information. Whereas the SAD showed promise for improving the extraction of\ bathymetry from lidar point clouds, the derived geomorphometry variables do not appear to describe\ geomorphometry well.

}, doi = {https://doi.org/10.3390/rs13091604}, author = {Kim Lowell and Brian R Calder} } @article {6959, title = {Estimating Observer and Data Reputation in Mariner-volunteered Bathymetry}, volume = {2021}, year = {2021}, month = {June 11}, pages = {77-96}, publisher = {International Hydrographic Organisation}, address = {Monaco}, abstract = {

Volunteered Bathymetric Information has the potential to assist authoritative charting but a lack of formal assessment methods has limited uptake of this idea. This paper proposes a reputation system for observers (and data) to estimate the observer\’s ability to match authoritative depths; a time-sequence estimate of vertical bias is also computed. This reputation can form the basis for decisions on how many observations are required from a VBI source before charting actions could be considered. Using data from the IHO DCDB and NOAA surveys from the Puget Sound area, bias estimate and reputation assessment are demonstrated for archetypal observers.

}, keywords = {Crowdsourced Bathymetry, Mobile Crowd Sensing, Observer Reputation, Ranking System, Volunteered Bathymetric Information, Volunteered Geographic Information}, author = {Brian R Calder} } @article {7064, title = {Extracting Shallow-water Bathymetry from Lidar Point Clouds Using Pulse Attribute Data: Merging Density-based and Machine Learning Approaches}, volume = {44(4) (DOI: https://doi.org/10.1080/01490419.2021.1925790)}, year = {2021}, month = {May 25}, pages = {259-286}, publisher = {Taylor and Francis}, abstract = {

To automate extraction of bathymetric soundings from lidar point clouds, two machine learning (ML[1]) techniques were combined with a more conventional density-based algorithm.\  The study area was four data \“tiles\” near the Florida Keys.\  The density-based algorithm determined the most likely depth (MLD) for a grid of \“estimation nodes\” (ENs).\  Unsupervised k-means clustering determined which EN\’s MLD depth and associated soundings represented ocean depth rather than ocean surface or noise to produce a preliminary classification.\  An extreme gradient boosting (XGB) model was fitted to pulse return metadata \– e.g., return intensity, incidence angle -- to produce a final Bathy/NotBathy classification.\  Compared to an operationally produced reference classification, the XGB model increased global accuracy and decreased the false negative rate (FNR) \– i.e., undetected bathymetry \– that are most important for nautical navigation for all but one tile.\  Agreement between the final XGB and operational reference classifications ranged from 0.84 to 0.999.\  Imbalance between Bathy and NotBathy was addressed using a probability decision threshold that equalizes the FNR and the true positive rate (TPR).\  Two methods are presented for visually evaluating differences between the two classifications spatially and in feature-space.

}, keywords = {airborne lidar, Extreme Gradient Boosting, Florida Keys, k-means clustering, shallow water bathymetry}, doi = {https://doi.org/10.1080/01490419.2021.1925790}, author = {Kim Lowell and Brian R Calder} } @article {7007, title = {Geomorphometric Descriptions of Archipelagic Aprons off the Southern Flanks of French Frigate Shoals and Necker Island Edifices, Northwest Hawaiian Ridge}, volume = {133(9/10)}, year = {2021}, month = {March 1}, pages = {2189-2209}, publisher = {Geological Society of America}, abstract = {

This study describes the geomorphometries of archipelagic aprons on the southern flanks of the French Frigate Shoals and Necker Island edifices on the central Northwest Hawaiian Ridge that are hotspot volcanoes that have been dormant for 10\–11 m.y. The archipelagic aprons are related to erosional headwall scarps and gullies on landslide surfaces but also include downslope gravitational features that include slides, debris avalanches, bedform fields, and outrunners. Some outrunners are located 85 km out onto the deep seafloor in water depths of 4900 m. The bedforms are interpreted to be the result of slow downslope sediment creep rather than products of turbidity currents. The archipelagic aprons appear to differ in origin from those off the Hawaiian Islands. The landslides off the Hawaiian Islands occurred because of oversteepening and loading during the constructive phase of the islands whereas the landslides off the French Frigate Shoals and Necker Island edifices may have resulted from vertical tectonics due to the uplift and relaxation of a peripheral bulge or isolated earthquakes long after the edifices passed beyond the hotspot. The lack of pelagic drape in water depths above the 4600 m depth of the local carbonate compensation depth suggests that the archipelagic apron off the French Frigate Shoals edifice is much younger, perhaps Quaternary in age, than that off the Necker Island edifice, which has a 50 m pelagic drape. The pelagic drape off the Necker Island edifice suggests that the landslides may be as old as 9 Ma. The lack of pelagic drape off the French Frigate Shoals edifice suggests that the most recent landslides are more recent, perhaps even Quaternary in age. The presence of a chute-like feature on the mid-flank of the French Frigate Shoals edifice appears to be the result of rejuvenated volcanism that occurred long after the initial volcanism ceased to build the edifice.

}, doi = {https://doi.org/10.1130/B35875.1}, author = {James V. Gardner and Brian R Calder and Andrew A. Armstrong} } @article {6856, title = {Horizontal Calibration of Vessels with UASs}, year = {2021}, month = {2021-03-03}, publisher = {Taylor and Francis}, abstract = {

Knowledge of offset vectors from vessel mounted sonars, to systems such as Inertial Measurement Units (IMUs) and Global Navigation Satellite Systems (GNSS) is crucial for accurate ocean mapping applications. Traditional survey methods, such as employing laser scanners or total stations, are used to determine professional vessel offset distances reliably. However, for vessels of opportunity that are collecting volunteer bathymetric data, it is beneficial to consider survey methods that are less time consuming, less expensive, and which do not involve bringing the vessel into a dry dock. Thus, this paper explores two alternative methods that meet this criterion for horizontally calibrating vessels.

Unmanned Aircraft Systems (UASs) can be used to perform cost-effective and quick surveys. Thus, UASs were utilized to horizontally calibrate a vessel with both Structure from Motion (SfM) photogrammetry and aerial lidar while the vessel was moored. Estimates of the horizontal deviations from ground truth, were obtained by comparing the horizontal distances between targets on a vessel, acquired by the UAS methods, to multiple ground truth sources: a survey-grade laser scan and fiberglass tape measurements. The investigated methods were able to achieve horizontal deviations on the order of centimeters with the use of Ground Control Points (GCPs).

}, keywords = {bathymetry, Crowdsourced Bathymetry, Remote Sensing, UAS, Vessel Calibration}, doi = {10.1080/01490419.2021.1879330}, author = {Casey O{\textquoteright}Heran and Brian R Calder} } @article {7066, title = {Identifying Future Hydrographic Survey Priorities: a Quantitative Uncertainty-based Approach}, volume = {2021}, year = {2021}, month = {June 11}, publisher = {International Hydrographic Organisation}, address = {Monaco}, abstract = {

There is no universal standard methodology for assessing the validity of hydrographic survey data and charted information as they age. NOAA\’s current method is the Hydrographic Health Model (HHM), a risk-based approach that incorporates crucial maritime variables and heuristic changeability terms through the history and frequency of large storms, tidal currents, and anthropogenic obstructions of a given area. Here we propose a quantitative approach evaluated in Chesapeake Bay and the Delmarva Peninsula that supports uncertainty-based estimates of chart health through alternative methodologies of calculating the initial state of historic hydrographic data and modeling how those change through time.

}, author = {Cassandra Bongiovanni and Thomas C Lippmann and Brian R Calder and Andrew A. Armstrong} } @article {7199, title = {Industry Discovery for Ocean Mapping Workflow Associated Challenges}, year = {2021}, month = {September 13-16}, pages = {Online}, abstract = {

Ocean mapping professionals are facing challenges in various areas of the hydrographic workflow. Understanding them can be difficult, as they are many and varied, but essential toward solving them. Some understanding can be reached with studying existing specifications and reports, however a more in-depth knowledge may be acquired directly from professionals in the field.

With a developing industry discovery project, we aim to identify the day-to-day challenges in data collection, data processing, chart compilation, research and development, production management, and use of products by end users. These insights, besides building awareness, can assist in designing new techniques, and in evaluating research directions.

This work presents the first phase of the project that focused on data collection and processing. It summarizes responses in regard to data, requirements for the deliverables, verification methods, and deficiencies of the process. The majority of participants were professional hydrographers and cartographers from various hydrographic offices, as well as the academia and private sector. Their responses have, unsurprisingly, confirmed the utmost importance of bathymetry, standards, and safety constraint in the domain, pointed out the mostly manual inspection of deliverables, and identified human related factors and the absence of automation, followed by problems with the data, as the most significant deficiencies of the process (Figure). We discuss that some of these deficiencies may be addressed with straightforward actions, e.g., training, better documentation, studies to increase awareness, while others are more challenging, e.g., automation, need for unpopular decisions from senior professionals, or probably impossible to overcome, e.g., human subjectivity.

}, keywords = {cartographic knowledge acquisition, hydrographic workflow, Nautical cartography, ocean mapping}, url = {https://www.researchgate.net/publication/354583304_Industry_discovery_for_ocean_mapping_workflow_associated_challenges}, author = {Christos Kastrisios and Brian R Calder} } @article {6961, title = {Measuring Shallow-water Bathymetric Signal Strength in Lidar Point Attribute Data Using Machine Learning}, volume = {35(8) (DOI:10.1080/13658816.2020.1925790)}, year = {2021}, month = {July 1}, pages = {1592-1610}, publisher = {Taylor and Francis}, abstract = {

The goal of this work was to evaluate if routinely collected but seldom used airborne lidar metadata \– \‘point attribute data\’ (PAD) \– analyzed using machine learning/artificial intelligence can improve extraction of shallow-water (less than 20 m) bathymetry from lidar point clouds. Extreme gradient boosting (XGB) models relating PAD to an existing bathymetry/not bathymetry classification were fitted and evaluated for four areas near the Florida Keys. The PAD examined include \‘pulse specific\’ information such as the return intensity and PAD describing flight path consistency. The R2 values for the XGB models were between 0.34 and 0.74. Global classification accuracies were above 80\% although this reflected a sometimes extreme Bathy/NotBathy imbalance that inflated global accuracy. This imbalance was mitigated by employing a probability decision threshold (PDT) that equalizes the true positive (Bathy) and true negative (NotBathy) rates. It was concluded that 1) the strength of the bathymetric signal in the PAD should be sufficient to increase accuracy of density-based lidar point cloud bathymetry extraction methods and 2) ML can successfully model the relationship between the PAD and the Bathy/NotBathy classification. A method is also presented to examine the spatial and feature-space distribution of errors that will facilitate quality assurance and continuous improvement.

}, keywords = {bathymetric mapping, Florida Keys, LIDAR, lidar metadata, Machine Learning}, doi = {10.1080/13658816.2020.1867147}, author = {Kim Lowell and Brian R Calder and Anthony P. Lyons} } @article {6777, title = {An alternative methodology (to the star symbols).}, year = {2020}, month = {February 7}, pages = {51}, institution = {International Hydrogarphic Organization}, chapter = {IHO Data Quality Working Group}, address = {Monaco}, abstract = {
Data quality is visualized in ECDIS as an additional layer with symbols using a rating system of stars: six to two stars for the best to lowest quality data and \“U\” for unassessed data. This work presents an alternative methodology for consideration by the IHO Data Quality Working Group members.
}, keywords = {Data uncertainty, Data Visualization, maritime navigation, Nautical cartography}, url = {https://www.researchgate.net/publication/339080041_An_alternative_methodology_to_the_star_symbols}, author = {Christos Kastrisios and Colin Ware and Brian R Calder and Butkiewicz, Thomas and Alexander, Lee} } @proceedings {6787, title = {BAG 2.0: Continuing Development of an Open, Grid-based Data Transfer Format}, year = {2020}, month = {February 25-27}, publisher = {Canadian Hydrographic Association}, address = {Quebec City, Quebec, Canada}, abstract = {

Since starting in 2003 as a side-conversation at a conference on the difficulties of transferring gridded data between hydrographic processing packages, the Open Navigation Surface project has been developed by the Open Navigation Surface Working Group, comprising government, industry, and academic partners, on a volunteer basis. The Bathymetric Attributed Grid (BAG) data format has gone on to be supported in many hydrographic data processing packages, and elsewhere, including commonly-used packages such as GDAL and tools that use it (such as ArcGIS, QGIS, Global Mapper, etc.). It also formed the original basis for the IHO S.102 standard for gridded bathymetry. Early in the process, the working group contributed code to implement a default library to read and write the developing data format so that new ideas could be tested, and new adopters would benefit from a reference implementation that makes concrete the assumptions and practices inherent to the format. Over the course of 15 years, however, the source code had been modified and extended many times, and was beginning to show its age. The working group have therefore begun the process of modernizing the application programming interface for the library, with particular emphasis on modern coding practices such as continuous integration, embedded documentation, and good object design. This paper describes the upcoming changes to the project, the basis for the design choices, and the implications for the user community. It also considers the benefits and challenges of maintaining a common, open-source data format with volunteer effort in a small community.

}, author = {Brian R Calder} } @article {6608, title = {A Design for a Trusted Community Bathymetry System}, year = {2020}, publisher = {Taylor and Francis}, abstract = {

Marine Volunteered Geographic Information (informally \“crowdsourced bathymetry\”) has raised much interest within the authoritative hydrographic community as a means to cheaply gather information to satisfy chart updating requirements. So far, however, a routine path to the official chart has been rare, mainly due to lack of calibration and other metadata that would satisfy liability concerns.\  As an alternative to these ideas, a data collection system is proposed which, by design, can auto-calibrate and provide other data quality guarantees, and thereby generate data that by construction should be qualified for hydrographic use.\  This idea is termed here Trusted Community Bathymetry (TCB). A design for such a system is outlined, and its performance demonstrated experimentally through a prototype system based on a low-cost, post-processed GNSS receiver and NMEA data logger.\  By comparison against NGS control and survey-grade GNSS equipment, it is shown that the TCB system achieves centimeter to decimeter-level positioning in 3D, auto-calibrates vertical offsets to the sonar transducer within a decimeter, and provides realtime uncertainty estimates for ellipsoid-referenced soundings. Additionally, in an underway field trial, the total vertical uncertainty of the soundings is shown to be within the limits required for IHO Order 1b (S.44, 5 Ed.) surveys.

}, keywords = {bathymetry, Crowdsourced Bathymetry, Ellipsoid-Referenced Survey, GNSS, Trusted Community Bathymetry, Volunteered Geographical Information}, doi = {DOI 10.1080/01490419.2020.1718255}, author = {Brian R Calder and Semme J Dijkstra}, editor = {Shannon Hoy and Kenneth Himschoot and Andrew Schofield} } @proceedings {6960, title = {Developing Machine Learning Models for Quality Assurance and Continuous Improvement of Bathymetry Extraction from Lidar Point Clouds}, year = {2020}, month = {February 24-27}, address = {Quebec City, Quebec, Canada}, keywords = {bathymetric mapping, LIDAR, Machine Learning}, author = {Kim Lowell and Brian R Calder and Anthony P. Lyons} } @proceedings {6774, title = {ENC Depth Areas: Quality Control of Sea-bottom Surface Continuity and Error Fixes}, year = {2020}, month = {February 24-27}, address = {Quebec City, Quebec, Canada}, abstract = {

The Electronic Navigational Chart (ENC) consists of point, line, and area features compiled following the nodechain topological model. To ensure that the topological structure is valid, the International Hydrographic Organization (IHO) has developed a number of checks defined in Publication S-58. Many of the checks deal with the vertical component of the nautical chart with the aim to validate consistency among compiled geoobjects. Nevertheless, validation checks are not exhaustive and spatial relationships may be violated. The presented work identifies vertical discontinuities between depth areas and adjoining geo-objects in the ENC and following an iterative approach proposes fixes to the attributes and the geometry of the depth areas with errors.

}, keywords = {ENC validation checks; automated nautical cartography; digital terrain modelling; topographic surface; nautical surface; surface reconstruction;}, doi = {10.6084/m9.figshare.11905599}, url = {https://www.conferium.com/OLM/Prg_Present.lasso?showevent=202}, author = {Christos Kastrisios and Brian R Calder and Megan Bartlett} } @proceedings {6786, title = {Estimating Crowdsourced, Authoritative Observer, and Data Reputation}, year = {2020}, month = {February 25-27}, publisher = {Canadian Hydrographic Association}, address = {Quebec City, Quebec, Canada}, abstract = {

Non-authoritative use of marine volunteered geographical information (MVGI), also known as Crowdsourced Bathymetry (CSB), is commonplace in the fishing and recreational markets through companies such as Olex, Navionics, CMap, and others. Use of MVGI for authoritative purposes (i.e., for updates of official charting data) has been significantly less widespread. Although many Hydrographic Offices have conducted limited experiments, and despite the IHO\’s enthusiastic endorsement, the liability, data availability, and processing workload associated with principles use of MVGI has led to slow uptake for routine use. The most commonly cited problem is lack of trust in the observations, particularly their vertical calibration. This paper therefore proposes to measure the reputation, or level of trust, that should be placed in observers across the spectrum from MVGI to Hydrographic Office surveyors, with the goal of dynamically adjusting the reputation of each observer over time as they make new observations that can be compared against other observers, or authoritative data. This model also extends to the data generated by the observers, which inherits the observer\’s reputation, but can then be confirmed or degraded over time with other observations, leading to application to chart adequacy and resurvey priority. Using a widely applied model for competitive ranking (predominantly used in chess ratings), two ranking stages are outlined: one that ranks observers against reference to determine their individual reputation, and a second that monitors the reference for drift and time-decay. The model allows for uncertainty in the rankings, and the decay of certainty due to time between comparisons. This model requires estimates of observer self-noise and bias, which are determined from time-series analysis of the observations. Using MVGI from the IHO Data Center for Digital Bathymetry, the paper demonstrates observer uncertainty calibration, ranking of observers, and the effects of time, and new observations, on archival authoritative data.

}, author = {Brian R Calder and Shannon Hoy} } @article {6761, title = {The Geomorphology of Submarine Channel Systems of the Northern Line Islands Ridge, Central Equatorial Pacific Ocean}, year = {2020}, month = {April 15}, pages = {24}, abstract = {

More than 844,000 km2 of the northern Line Islands Ridge mapped with multibeam bathymetry and backscatter provide unprecedented views of the geomorphology of this isolated area in the central equatorial Pacific Ocean. A compilation of all available multibeam data in the area reveals six extensive submarine dendritic channel systems that encompass a combined drainage area that exceeds 60,000 km2. The channel systems occur in a predominately carbonate environment and are the longest calciclastic submarine channel systems mapped in the oceans to date. The channel systems occur in a carbonate-dominated region well above the carbonate compensation depth and have developed into the surface of basins that are surrounded by small guyots and seamounts that make up a discontinuous rim around the summit of the northern Line Island Ridge. The channels have mostly straight or gently curved well-developed tributaries and main reaches. Although the Line Island Ridge has been dated at 86 to 68 Ma old, the channels occur on the surface and are not buried by any significant sediment accumulations. Levees are very rare along the channel banks and no bathymetric expression of submarine fans was found where the channels exit onto the adjacent abyssal basins. There is sparse evidence of landslide deposits throughout the ridge although the flanks of the guyots exhibit numerous headwall scarps. The presence of plunge pools below the northwest escarpment, together with well-defined channels meters to hundreds of meters deep relative to the surrounding seafloor, suggests the channels might be relatively recent (perhaps late Neogene or even younger) features developed long after the ridge subsided more than a kilometer below sea level.

}, doi = {10.3389/feart.2020.00087}, author = {James V. Gardner and Jeffrey Peakall and Andrew A. Armstrong and Brian R Calder} } @proceedings {6788, title = {Horizontal Calibration of Vessel Lever Arms Using Unmanned Aircraft Systems (UASs)}, year = {2020}, month = {February 25-27}, publisher = {Canadian Hydrographic Association}, address = {Quebec City, Quebec, Canada}, abstract = {

Knowledge of lever arm distances from sonars, mounted on vessels, to systems such as Inertial Measurement Units (IMUs) and Global Navigation Satellite Systems (GNSS) is crucial for accurate ocean mapping applications. Traditional methods, such as laser scanners or total stations, are used to determine professional survey vessel lever arm distances reliably. However, for vessels of opportunity that are collecting volunteer bathymetric data, it is beneficial to consider survey methods that are less time consuming, less expensive, and which do not involve bringing the vessel into a dry dock. With the development of Unmanned Aircraft Systems (UASs) in the field of mapping, more cost-effective and quicker surveys can be conducted. To investigate the feasibility of conducting accurate horizontal lever arm surveys of vessels, while maximizing time efficiency in data collection, UAS surveys of a vessel with calibrated lever arm distances were conducted using both Structure for Motion (SfM) photogrammetry and aerial LiDAR while the vessel was docked at the pier. Estimates of the horizontal errors, for both methods, were obtained by comparing the horizontal distances between targets acquired by the UAS methods to ground-truth measurements of lever distances from survey-grade laser scanning of the vessel. With the use of Ground Control Points (GCPs), horizontal errors of both the photogrammetry and LiDAR models are on the order of centimeters, with the LiDAR model being slightly higher in horizontal error than most of the photogrammetry models.

}, author = {Casey O{\textquoteright}Heran and Brian R Calder} } @article {6778, title = {An Improved Method for Portraying CATZOC in ECDIS}, year = {2020}, month = {January 29-30}, publisher = {Shipping Federation of Canada}, address = {Montreal, Canada}, abstract = {
This work presents our research towards the visualization and integration of bathymetric data uncertainty in support of marine navigation. It focuses on our proposed improved method for the visualization of zones of confidence (ZOC) and quality of bathymetric data (QoBD) on ECDIS.
}, keywords = {Data uncertainty, Data Visualization, maritime navigation, Nautical cartography}, doi = {10.13140/RG.2.2.15750.73288}, url = {http://www.shipfed.ca/5deffee720991}, author = {Christos Kastrisios and Colin Ware and Brian R Calder and Butkiewicz, Thomas and Alexander, Lee} } @proceedings {6780, title = {Improved Techniques for Depth Quality Information on Navigational Charts}, volume = {1}, year = {2020}, pages = {73-80}, address = {Nessebar, Bulgaria}, abstract = {

Navigational charts contain a combination of geospatial information of varying quality collected at different times using various techniques.Bathymetric data quality is mainly encoded in electronic charts with the Category of Zones of Confidence (CATZOC). CATZOC provides information about the horizontal and vertical uncertainty of depth information, as well as the seabed coverage and feature detection. It is visualized in Electronic Chart Display and Information Systems (ECDIS) as an additional layer with glyphs using a rating system of stars: six to two stars for the best to lowest quality data and \“U\” for unassessed data. The current symbology creates visual clutter which is worse in areas of high quality bathymetry. Furthermore, horizontal and vertical uncertainties may not be adequately assessed by the user. This paper presents a research program aimed at the development of a method for portraying bathymetric data quality and for integrating the quantified uncertainties in ECDIS.

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}, keywords = {bathymetric data uncertainty, Electronic Navigational Charts ENC, Error-band geometry, safety of navigation, spatial data visualization, Uncertainty Visualization, Visual Variables}, author = {Christos Kastrisios and Colin Ware and Brian R Calder and Butkiewicz, Thomas and Alexander, Lee and Rogier Broekman} } @proceedings {6779, title = {Inspection and Error Remediation of Bathymetric Relationships of Adjoining Geo-Objects in Electronic Navigational Charts}, volume = {1}, year = {2020}, pages = {116-123}, address = {Nessebar, Bulgaria}, abstract = {
Depth areas are utilized by the Electronic Chart Display and Information Systems (ECDIS) along with the vessel\&$\#$39;s characteristics (e.g., draft, squat) and other situational information (e.g., tides) for separating safe areas from those unsafe to navigate. Any error in their compilation is carried over to the analysis performed in the ECDIS. As a result, waters may be portrayed deeper, thus posing a risk to the vessel navigating them, or may appear shoaler, thus triggering useless ECDIS alarms which contribute to the situation known as \"mariner\&$\#$39;s deafness\". With the exception of crisp boundaries where abrupt changes are expected, the transition between depth areas should be smooth and continuous. In this paper we present a research toward a mechanism for identifying discontinuities and an error remediation approach that proposes changes to the encoded depth range and the geometry of depth areas with identified discontinuities, for the cartographer\&$\#$39;s attention.
}, keywords = {automated nautical cartography, Depth areas, digital terrain modelling, ENC validation checks, nautical surface, safety of navigation, topographic surface}, author = {Christos Kastrisios and Brian R Calder and Megan Bartlett} } @article {6776, title = {Nautical Chart Data Uncertainty Visualization as the Means for Integrating Bathymetric, Meteorological, and Oceanographic Information in Support of Coastal Navigation}, year = {2020}, month = {January 12-17}, pages = {Boston, MA}, abstract = {
Most navigational charts are an amalgamation of geospatial information of varying quality collected using different techniques at different times. Data collected with high resolution multi-beam echo sounders or lidar systems may co-exist on the chart with data collected with lead-line as far back as the 18th century. Data quality on charts is currently provided as a series of Category Zone of Confidence (CATZOC) values. For every part of the chart, CATZOC values provide information about the horizontal and vertical uncertainty of bathymetric information, as well as the seabed coverage and feature detection. CATZOC is portrayed in ECDIS as an additional layer with glyphs using a rating system of stars: six to two stars for the best to lowest quality data and \“U\” for unassessed data. With the provided information mariners may interpret the seabed morphology, identify shoals that pose a threat for the plotted voyage, and select routes that maintain under-keel clearance, however it is not always well understood and utilized by mariners. The aim of this research work is the development of new visualization and integration methods of data quality on charts to support decision making on board. In this two-fold work we begin with investigating new visualization methods for the bathymetric data uncertainty on charts and we subsequently utilize the results of the visualization work for the integration of marine navigation related information in support of decision making and safe navigation of ships.
}, keywords = {Data uncertainty, Data Visualization, maritime navigation, Nautical cartography}, doi = {10.6084/m9.figshare.12196764}, url = {https://www.researchgate.net/publication/337869522_Nautical_chart_data_uncertainty_visualization_as_the_means_for_integrating_bathymetric_meteorological_and_oceanographic_information_in_support_of_coastal_navigation}, author = {Christos Kastrisios and Colin Ware and Brian R Calder and Butkiewicz, Thomas and Alexander, Lee and Olivia Hauser} } @article {6937, title = {Ryder Glacier in Northwest Greenland is Shielded from Warm Atlantic Water by a Bathymetric Sill}, volume = {45}, year = {2020}, month = {November 4}, publisher = {Springer Nature}, abstract = {

The processes controlling advance and retreat of outlet glaciers in fjords draining the Greenland Ice Sheet remain poorly known, undermining assessments of their dynamics and associated sea-level rise in a warming climate. Mass loss of the Greenland Ice Sheet has increased six-fold over the last four decades, with discharge and melt from outlet glaciers comprising key components of this loss. Here we acquired oceanographic data and multibeam bathymetry in the previously uncharted Sherard Osborn Fjord in northwest Greenland where Ryder Glacier drains into the Arctic Ocean. Our data show that warmer subsurface water of Atlantic origin enters the fjord, but Ryder Glacier\’s floating tongue at its present location is partly protected from the inflow by a bathymetric sill located in the innermost fjord. This reduces under-ice melting of the glacier, providing insight into Ryder Glacier\’s dynamics and its vulnerability to inflow of Atlantic warmer water.

}, doi = {https://doi.org/10.1038/s43247-020-00043-0}, author = {Martin Jakobsson and Larry A Mayer and Johan Nilsson and Christian Stranne}, editor = {Brian R Calder and Matt O{\textquoteright}Regan and John Farell and Thomas M. Cronin and Volker Br{\"u}chert and Julek Chawarski and Bjorn Eriksson and Jonas Fredriksson and Laura Gemery and Anna Glueder and Felicity A. Holmes and Kevin Jerram and Nina Kirchner and Alan Mix and Julia Muchowski and Abhay Prakash and Brendan Reilly and Brett Thornton and Adam Ulfsbo and Elizabeth Weidner and Henning {\r A}kesson and Tamara Handl and Emelie St{\r a}hl and Lee-Gray Boze and Samuel Reed and Gabriel West and June Padman} } @proceedings {6775, title = {Soundings Validation: Toolbox Research to Operations}, year = {2020}, month = {February 24-27}, address = {Quebec City, Quebec, Canada}, abstract = {

Charted bathymetry encompasses the cartographer\’s effort to accurately describe submarine topography based on the source information. A key factor in the selection process is that, at any location, the charted features do not give a false impression that the water depth is deeper than it actually is. Our research work focused on development of an\ automated solution for the identification of locations where this goal is violated. We present the research work from conceptualization to the development of an ArcGIS Toolbox\ named \“Sounding Validation Toolbox\” that consists of three automated tools, as well as the challenges and results in the process of making it operational with the Marine Chart Division of NOAA/Office of Coast Survey.

}, keywords = {nautical surface test; triangle test; selected soundings; automated nautical cartography; charted soundings}, doi = {10.6084/m9.figshare.12196185}, url = {https://www.conferium.com/OLM/Prg_Present.lasso?showevent=202}, author = {Christos Kastrisios and Brian R Calder and Giuseppe Masetti and Brian Martinez and Peter Holmberg} } @proceedings {6547, title = {On the Effective Validation of Charted Soundings and Depth Curves}, year = {2019}, month = {March 18-21}, address = {Biloxi, MS}, abstract = {

Depth curves and charted soundings are two structural components of nautical charts, both derived from a more detailed dataset through generalization. Once depth curves are generated, the cartographer makes a selection of soundings that complements the depth curves and other features carrying bathymetric information in the adequate representation of the seabed morphology at the scale of the product. The selection of charted soundings \– which is currently either performed fully manually, or partially manually using a computer-assisted solution \– must meet the safety constraint, i.e., that no source sounding exists that is shoaler than what the mariner would expect by mentally interpolating the charted bathymetric information. According to International Hydrographic Organization S-4 publication, for well-surveyed areas that is achieved through the \“triangular method of selection\” and consists of two tests: the Triangle Test and the Edge Test. There are currently no fully automated solutions, so, with the ultimate goal of supporting \“cartography at point of use\”, we consider the problem of automating the validation of shoal-selected soundings. We discuss an implementation of the triangle test with improved performance near linear features, the first automated implementation of the edge test, and that the edge test may identify shoals that the triangle test fails to detect, confirming its significance in the validation process. We demonstrate an \“intrinsic\” limitation of the two tests that makes infeasible a fully automated solution based solely on the two tests. Finally, to overcome the intrinsic limitation, we propose a new validation test, named Nautical Surface Test, that captures the local morphology at the appropriate charting resolution as the solution for the automated validation of the charted bathymetric information.

}, keywords = {Analytical cartography, Computer cartography, Data Generalization, Delaunay Triangulation, depth interpolation, Nautical cartography, nautical surface test, Sounding Selection}, doi = {https://doi.org/10.13140/RG.2.2.18705.89440}, author = {Christos Kastrisios and Brian R Calder and Giuseppe Masetti and Peter Holmberg} } @proceedings {6605, title = {High Frequency Motion Residuals in Multibeam Data: Identification and Estimation}, year = {2019}, month = {March 19 - 21}, publisher = {The Hydrographic Society of America}, address = {Biloxi, MS}, abstract = {

Advances in multibeam sonar mapping and data visualization have increasingly brought to light the subtle integration errors remaining in bathymetric datasets. Currently, traditional field calibration procedures (the patch test) just account for static orientation bias and sonar to position latency. However, this ignores the generally more subtle integration problems that generate time varying depth errors.

Such dynamic integration errors are the result of an unknown offset in one or more of orientation, space, sound speed or time between the sonar and ancillary sensors. Such errors are systematic, and thus should be predictable, based on their relationship between the input data and integrated output. A first attempt at addressing this problem utilized correlations between motion and ping-averaged residuals [1]. The known limitations of that approach, however, included only being able to estimate the dominant signal, imperfectly accounting for irregular sounding distribution and it only working in shallow water.

This paper presents a new and improved means of utilizing the dynamics of the integration error signatures which can address multiple issues simultaneously, better account for along-track sounding distribution, and is not restricted to the shallow water geometry. Through considering soundings from extended sections of a single swath, the motion-driven signatures of multiple integration errors may be simultaneously identified. Such an approach provides a means of underway system optimization using nothing more than the bathymetry of typical seafloors acquired during transit. Successful estimation, however, imposes conditions of significant vessel motion, and smooth, gently rolling bathymetry. Initial results of the new algorithm are presented using data generated from a simulator (with known inputs and integration errors) to test the efficacy of the method.

}, author = {Brandon Maingot and John E. Hughes Clarke and Brian R Calder} } @article {6595, title = {Improving Extraction of Bathymetry from Lidar Using Machine Learning}, year = {2019}, month = {June 4-6}, pages = {Notre Dame, IN}, abstract = {

Three ML techniques \– artificial neural networks (ANNs), extreme gradient boosting (XGB), and regularized logistic regression (RLR) \– have been applied to lidar pulse return meta-data to estimate the probability that each return is bathymetry -- p(Bath) -- for four tiles from a NOAA Remote Sensing Division shallow-water data in the Florida Keys. To facilitate operationalization, the meta-data are extracted from the point cloud alone \– i.e., no ancillary data are employed. Three types of meta-data are being explored: return-specific, ocean floor topography, and flight path crenularity.

Major conclusions to date are:

Ultimately, the p(Bath) estimate will be integrated into an already-operational lidar-extraction algorithm.

}, keywords = {Lidar Data Processing, Machine Learning}, author = {Kim Lowell and Brian R Calder} } @proceedings {6716, title = {Machine Learning Strategies for Enhancing Bathymetry Extraction from Imbalanced Lidar Point Clouds}, year = {2019}, month = {October 27-31}, publisher = {IEEE}, address = {Seattle, WA}, abstract = {

Density-based approaches to extract bathymetry from airborne lidar point clouds generally rely on histogram/frequency-based disambiguation rules to separate noise from signal. The present work targets the improvement of such disambiguation rules by enhancing each pulse with a machine learning-based estimate of its p(Bathy) \– i.e., its probability of truly being bathymetry. Extreme gradient boosting (XGB) is used to assess the strength of bathymetric signal in pulse return metadata. Because lidar point clouds can be highly imbalanced between Bathymetry and NotBathymetry, three strategies for mitigating the effects of imbalanced samples were examined. Impacts of an imbalanced lidar point cloud were successfully mitigated by:

1.\ Applying an \“optimal\” decision threshold (ODT) that equalizes accuracy for Bathymetry and NotBathymetry to p(Bathyrather than using a conventional probability decision threshold (PDT) of 0.50, and

2.\ Using proportional class weighting to fit the XGB model.

However, decomposing a confusion matrix by iteratively discarding misclassified points and re-fitting an XGB model was not successful in improving the strength or detectability of the bathymetric signal in the metadata. The same was true for iteratively discarding correctly classified points.

The bathymetric signal in the metadata was found to be sufficiently strong to explore the operational incorporation of results into the disambiguation rules of density-based bathymertric extraction methods.

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}, keywords = {bathymetric lidar, confusion matrix decomposition, Extreme Gradient Boosting, imbalanced samples, probability decision threshold}, author = {Kim Lowell and Brian R Calder} } @proceedings {6705, title = {Machine Learning Strategies for Enhancing Bathymetry Extraction from Imbalanced Lidar Point Clouds}, year = {2019}, month = {Oct 27-31}, publisher = {IEEE}, address = {Seattle, WA}, abstract = {

Abstract\—Density-based approaches to extract bathymetry from airborne lidar point clouds generally rely on histogram/frequency-based disambiguation rules to separate noise from signal.\  The present work targets the improvement of such disambiguation rules by enhancing each pulse with a machine learning-based estimate of its p(Bathy) \– i.e., its probability of truly being bathymetry.\  Extreme gradient boosting (XGB) is used to assess the strength of bathymetric signal in pulse return metadata.\  Because lidar point clouds can be highly imbalanced between Bathymetry and NotBathymetry, three strategies for mitigating the effects of imbalanced samples were examined.\  Impacts of an imbalanced lidar point cloud were successfully mitigated by:

However, decomposing a confusion matrix by iteratively discarding misclassified points and re-fitting an XGB model was not successful in improving the strength or detectability of the bathymetric signal in the metadata.\  The same was true for iteratively discarding correctly classified points.

The bathymetric signal in the metadata was found to be sufficiently strong to explore the operational incorporation of results into the disambiguation rules of density-based bathymertric extraction methods.

}, keywords = {bathymetric lidar, confusion matrix decomposition, Extreme Gradient Boosting, imbalanced samples, probability decision threshold}, author = {Kim Lowell and Brian R Calder} } @article {6623, title = {Opening the Black Boxes in Ocean Mapping: Design and Implementation of the HydrOffice Framework}, year = {2019}, month = {July 11}, pages = {Freemantle, WA, Australia}, abstract = {

Modern ocean mapping relies heavily on complex algorithms that may strongly affect the reported outputs (e.g., gridded bathymetry, acoustic mosaics). When implemented in commercial software, these algorithms usually cannot be directly examined, and thus represent black boxes.

To ease the understanding of existing algorithms and the creation of better tools for ocean mapping, since 2016 the UNH Center for Coastal and Ocean Mapping and NOAA Office of Coast Survey have been developing an open research framework containing applications that cover all phases of the ping-to-public process. This effort, called HydrOffice, aims to facilitate data acquisition, to automate and enhance data processing, and to improve survey products. These themes are driving the creation of a growing collection of hydro-packages, each dealing with specific aspects of the ocean mapping workflow. The overall goal is to speed up the testing of new ideas and the Research-to-Operations (R2O) transition by minimizing the effort to develop and test new ideas.

HydrOffice has developed a number of applications that encode both existing specifications and long-term best practices, while enabling and extending recent discoveries and research-driven techniques. In return, many users have reported HydrOffice increases workflow efficiency, confirming the benefits of this approach.

}, keywords = {hydroffice, ocean mapping, open tools}, doi = {10.13140/RG.2.2.18516.55681}, url = {https://www.researchgate.net/publication/334611395_Opening_the_Black_Boxes_in_Ocean_Mapping_Design_and_Implementation_of_the_HydrOffice_Framework}, author = {Giuseppe Masetti and Tyanne Faulkes and Brian R Calder} } @article {6334, title = {Parallel Variable-Resolution Bathymetric Estimation with Static Load Balancing}, volume = {123}, year = {2019}, month = {2018}, pages = {72-82}, publisher = {Elsevier}, abstract = {
A method for partitioning a large computation task (direct, variable resolution bathymetric grid construction from raw observations) into thread-parallel code is described.\  Based on the data density estimated for the first pass of the CHRT algorithm, this algorithm statically partitions the estimation task into spatially distinct blocks of approximately equal total data observation count so that each can be executed in parallel and be expected to complete approximately concurrently.\  No communication between blocks or further load balancing is therefore required.\  A branch-and-bound algorithm is used to control the complexity of the partitioning task, but the computation time increases significantly as more partitions are required, leading to a degree of diminishing returns for allocating further computational resources and suggesting alternative approaches for high thread-count systems.\  Speed-up of the algorithm over a pair of test datasets (using real-world hydrographic survey data) shows that the performance consistently improves with the number of computational tasks assigned, initially (super-) linearly, although ultimately sub-linearly as other resource sharing limitations take over.\  An overall speedup of 4.1 times is demonstrated with a quad-core single-processor workstation.
}, keywords = {Parallel processing; CHRT; CUBE; Data-driven estimation; Branch and bound; Bathymetric data processing; Surface estimation}, doi = {https://doi.org/10.1016/j.cageo.2018.11.011}, url = {https://www.sciencedirect.com/science/article/pii/S0098300418304217}, author = {Brian R Calder} } @proceedings {6596, title = {Resolution Determination through Level of Aggregation Analysis}, year = {2019}, month = {March 19-21}, publisher = {The Hydrographic Society of America}, address = {Biloxi, MS}, abstract = {
In order to accommodate significantly varying depths within a survey area, and the consequent data density changes, variable-resolution depth modeling technologies are now being deployed. A core question for such technologies is how to determine the appropriate spatially-varying resolution at which to estimate or model the seafloor in a computationally efficient manner. Current methods include conversion from roughly-estimated depth or data density to resolution, or spatially-recursive sub-division (typically via a quadtree) with an appropriate similarity metric, typically working on a coarse-to-fine basis (i.e., starting with the whole survey area, and working to finer scales as the resolution is determined). All of these methods require a preliminary pass through the source data, and make various assumptions about its structure. Computational efficiency and level of assumptions are therefore important for implementation.
As an alternative to these techniques, this paper describes a fine-to-coarse method based on a \"level of aggregation\" metric which makes no assumptions about the structure of the data, allowing it to be used equally on acoustic, lidar, or random point data. This method is methodologically direct and simple, data adaptive, readily parallelized, and automatically determines both the rate at which resolution is changing and the final resolution within this structure.
The method is illustrated in the context of processing Riegl VQ-880-G high-resolution shallow lidar data, and mixed-sensor acoustic data from a NOAA survey, with particular attention to parallel and distributed implementation. A direct corollary of estimating resolution is the ability to assess whether a given data set can meet survey specifications, which effectively provides a measure of how \"surveyed\" an area is.\  This is illustrated on an archive collection of random data from the U.S. Atlantic Margin in the context of Seabed 2030.
}, keywords = {Bathymetric Modeling, Bathymetric Processing, Digital Elevation Model, hydrography, Resolution Detemination, seabed 2030}, author = {Brian R Calder} } @proceedings {6598, title = {Sensing for Hydrographic Autonomous Surface Vehicles}, year = {2019}, month = {March 19-21}, publisher = {The Hydrographic Society of America}, address = {Biloxi, MS}, abstract = {

With increasing interest in the use of autonomous surface vessels (ASVs) to automate hydrographic data collection in support of safe navigation, there is a growing likelihood that ASVs will be operated in regions with uncertain or limited prior knowledge of where it is safe to navigate. In addition to this challenge, coastal environments may have significant boat traffic and other hazards for an unmanned vehicle, such as buoys, lobster pots and kelp. If ASVs are to operate safely and truly autonomously, means must be developed to increase the awareness of the ASV to its environment so that it can safely maneuver with minimal operator intervention.

This paper provides a review of a variety of sensing systems used by ASVs for the identification of obstacles on the surface and underwater, their detection and classification capabilities, and their limitations and uncertainties. AIS, radar, LiDAR, color and infrared (FLIR) cameras, multibeam echo-sounders and forward looking sonar are considered. The paper will explore how to use the complementary nature of these sensors in order to offer the best possible environmental perception and situational awareness. In addition, the paper will look at a number of obstacle types, evaluate their detection requirements, and match these requirements with the sensors available aboard the ASV, including the determination of which sensors provide actionable information natively, and which require further algorithm development. Finally, the use of deep learning algorithms will be examined using data from the ASV\’s camera to better understand the applicability of deep learning for the detection of objects in the marine environment.

}, keywords = {asv, Autonomous Survey Systems, Sensor Fusion}, author = {Coral Moreno and Val Schmidt and Brian R Calder and Larry A Mayer} } @article {6349, title = {Total Vertical Uncertainty (TVU) modeling for topo-bathymetric lidar systems}, volume = {85}, year = {2019}, pages = {585-596}, publisher = {American Society for Photogrammetry and Remote Sensing}, abstract = {
This paper presents a comprehensive total vertical uncertainty
(TVU) model for topo-bathymetric Light Detection and
Ranging (LIDAR) systems. The TVU model consists of a combination
of analytical uncertainty propagation for the subaerial
(above water) portion and Monte Carlo simulation models
for the subaqueous portion (water surface to seafloor). The
TVU model was tested on a topo-bathymetric LIDAR data set
collected by National Oceanic and Atmospheric Administration\’s
National Geodetic Survey (NGS) in Southwest Florida,
U.S., in May 2016 using a Riegl VQ-880-G topo-bathymetric
LIDAR system. The TVU values were compared against the
empirical standard deviation and were found to capture the
variability of uncertainty with depth while providing (slightly)
conservative estimates of uncertainty. The results may be
used to inform data acquisition protocols and data processing
models. The model implementation is now beginning to be
used operationally at NGS for topo-bathymetric LIDAR projects.

}, keywords = {LIDAR, Riegl VQ-880-G, total propagated uncertainty, uncertainty modelling}, doi = {10.14358/PERS.85.8.585}, author = {Eren, Firat and J. Jung and Christopher E Parrish and Forfinski, Nick and Brian R Calder} } @article {6447, title = {Towards Automated Validation of Charted Soundings: Existing Tests and Limitations}, volume = {22(4)}, year = {2019}, month = {June 3}, publisher = {Taylor \& Francis}, abstract = {

The nautical chart is one of the fundamental tools in navigation used by mariners to plan and safely execute voyages. Its compilation follows strict cartographic constraints with the most prominent being that of the safety. Thereby, the cartographer is called to make the selection of the bathymetric information for portrayal on charts in a way that, at any location, the expected water depth is not deeper than the source information. To validate the shoal-biased pattern of selection two standard tests are used, i.e. the triangle and edge tests. To date, some efforts have been made towards the automation of the triangle test, but the edge test has been largely ignored. In the context of research on a fully automated solution for the compilation of charts at different scales from the source information, this paper presents an algorithmic implementation of the two tests for the validation of selected soundings. Through a case study with real-world data, it presents the improved performance of the implementation near and within depth curves and coastlines and points out the importance of the edge test in the validation process. It also presents the, by definition, intrinsic limitation of the two tests as part of a fully automated solution and discusses the need for a new test that will complement or supersede the existing ones.

}, keywords = {automated nautical cartography, category zone of confidence, chart discrepancies, chart safety constraint, nautical chart generalization, nautical surface test, selected soundings, sounding generalization, Sounding Selection}, doi = {https://doi.org/10.1080/10095020.2019.1618636}, author = {Christos Kastrisios and Brian R Calder and Giuseppe Masetti and Peter Holmberg} } @proceedings {6665, title = {Validation of the Shoal-Biased Pattern of Bathymetric Information on Nautical Charts}, volume = {1}, year = {2019}, month = {July15-20}, publisher = {International Cartorgaphic Association}, address = {Tokyo, Japan}, keywords = {chart safety constraint, nautical chart generalization, Sounding Selection, Triangle Test}, doi = {10.5194/ica-abs-1-163-2019}, url = {https://www.researchgate.net/publication/334504598_Validation_of_the_shoal-biased_pattern_of_bathymetric_information_on_nautical_charts}, author = {Christos Kastrisios and Brian R Calder and Giuseppe Masetti and Peter Holmberg} } @proceedings {6597, title = {The Viability of Crowdsourced Bathymetry for Authoritative Use}, year = {2019}, month = {March 19-21}, publisher = {The Hydrographic Society of America}, address = {Biloxi, MS}, abstract = {

Crowdsourced bathymetry (CSB) is increasingly common amongst private organizations that provide navigational products to mariners (e.g., Olex, Navionics, and TeamSurv), prompting the desire among hydrographic offices to integrate CSB into the authoritative charting pipeline. However, questions of data quality along with the legal responsibility to provide soundings safe for navigation have led to a five-year debate on the role CSB can and should play in official practices. Recently, both local and international hydrographic communities have progressed with CSB, including the production of an international guidance document, establishment of the IHO/DCDB CSB database, and nascent integration of CSB data into some hydrographic workflows. However, despite forward momentum, consensus on the utility of CSB for authoritative purposes has yet to be reached. This study aims to provide clarity on the viability of authoritative CSB by examining four fundamental components: the crowd (capability and motivation), the data (accuracy and, subsequently, application), the economics (cost vs. reward), and ultimately, the responsibility of hydrographic offices. The culmination of these investigations demonstrates that while CSB is unable to meet charting standards (and is therefore most suited for ancillary tasks e.g., survey prioritization and change detection), hydrographic offices have a responsibility to report dangers to navigation to the mariner and, therefore, must incorporate CSB into the chart. A recommended model for how to accomplish this is presented.

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}, keywords = {Crowdsourced Bathymetry, CSB, hydrography}, author = {Shannon Hoy and Brian R Calder} } @proceedings {6536, title = {Algorithmic Implementation of the Triangle Test for the Validation of Charted Soundings}, year = {2018}, month = {June 18 {\textendash} 23}, pages = {569-576}, publisher = {Bulgarian Cartographic Association}, address = {Sozopol, Bulgaria}, abstract = {

The selection of soundings to be shown on nautical charts is one of the most important and complicated tasks in nautical cartography. From the vast number of source soundings the cartographer is called to select all those important for the safety of navigation and to verify the \“shoal biased\” pattern of selection against the source soundings. A long-term goal of the cartographic community has been the automation of the tasks involved in nautical chart production, including that of the selection and validation of charted soundings. With the aim to contribute to that effort, this paper presents an implementation of the triangle test for the automated validation of selected soundings which has improved performance on the detection of shoals near depth curves and coastlines

}, keywords = {Analytical cartography, Computer cartography, Data Generalization, Delaunay Triangulation, Nautical cartography, Sounding Selection}, doi = {https://doi.org/10.13140/RG.2.2.12745.39528}, url = {https://www.researchgate.net/publication/325966938_Algorithmic_implementation_of_the_triangle_test_for_the_validation_of_charted_soundings}, author = {Christos Kastrisios and Brian R Calder} } @article {6405, title = {Applications of Sonar Detection Uncertainty for Survey Quality Control and Data Processing}, year = {2018}, month = {October 1-3}, pages = {St. John{\textquoteright}s, NL, Canada}, abstract = {

An objective measurement of the bathymetric uncertainty introduced by sonar bottom detection has been proposed (Lurton and Augustin, 2009) to overcome the sonar-specific heuristic solutions proposed by constructors. This approach pairs each sounding with an estimation of sonar detection uncertainty (SDU) based on the width of the signal envelope (amplitude detection) or the noise level of the phase ramp (phase detection), thus capturing the intrinsic quality of the received signal and any applied signal-processing step.

Along with the environment characterization and the motion sensor accuracy, the SDU represents a major contributor to the total vertical uncertainty (TVU). As such, the monitoring of the SDU statistics by detection types, acquisition modes, and transmission sectors (when available) provides an effective way to alert the surveyor about ongoing issues in the data collection. It also has potential application in the evaluation of the health status of the sonar - for example, by comparing SDU-derived performance of repeated surveys on the same seafloor area and estimating the uncertainty contributions from environment and motion. Finally, the SDU may be integrated in multiple stages of the data processing workflow, from data pre-filtering to hydrographic uncertainty modeling, up to more advanced applications like hypotheses disambiguation in statistical gridding algorithms (e.g., CUBE).

Based on such considerations, we conducted a study to explore possible applications of the estimated SDU values for survey quality control and data processing. The results of the analysis applied to real data \– collected using multibeam echosounders from manufacturers who are early adopters of this metric (i.e., Kongsberg Maritime and Teledyne Reson) \– provide evidence that SDU is a useful tool for survey monitoring.

}, keywords = {hydrographic uncertainty model, quality factor, sonar detection uncertainty}, doi = {https://doi.org/10.13140/RG.2.2.24445.00485/1}, url = {http://www.shallow-survey.com/Conference,Program/}, author = {Giuseppe Masetti and Augustin, Jean-Marie and Xavier Lurton and Brian R Calder} } @article {6336, title = {Computer-Assisted Processing for Topobathy Lidar Data}, year = {2018}, month = {June 26 - 28}, pages = {Providence, RI}, abstract = {

The advent of topobathy lidar has dramatically increased the data collected in a lift, with obvious consequences for data timeliness. For similar reasons, acoustic bathymetry processing has transitioned from selection/classification of individual observations to computer-assisted depth estimation, using the observation uncertainties to weight the contribution to depth, and perform unsupervised classification into self-consistent observation clusters.

We adapt here an acoustic tool to topobathy data.\ From a data-adaptive resolution determination, this method estimates a variable-resolution DTM from raw data, where each node can have multiple, simultaneously valid, estimates of depth. Conventional depth disambiguation is ineffective with the estimated 75\% outlier rate; a new vector-quantized hidden Markov model technique is therefore proposed.\ This machine learning method develops a clean depth reconstruction, while allowing for a \“no reconstruction\” solution in areas with no real depth observations.

This offers efficient, automatic processing, and the opportunity to align bathymetric processing methods, with obvious benefit for training, output compatibility, and workflow management.

}, author = {Brian R Calder} } @proceedings {6335, title = {Design of a Trusted Community Bathymetry System}, year = {2018}, month = {March 27 - 29}, publisher = {Canadian Hydrographic Association}, address = {Victoria, BC, Canada}, abstract = {
Crowd-sourced bathymetry (CSB), meaning volunteered geo-spatial information collected from whatever GNSS and sonar system is available on the volunteer\&$\#$39;s vessel, has received a significant amount of attention in recent years.\ Although increasing amounts of data are being collected, attributed with metadata (to different degrees), and archived, finding a route to the nautical chart has so far been problematic.\ Partially, this is to do with a lack of a formal and robust means to represent data quality on the chart (paper, raster, or vector), but mostly it is to do with a lack of qualifying metadata associated with data collected in this manner. CSB efforts generally suffer from a lack of calibration, and are therefore limited by uncontrolled vertical offsets with respect to the waterline that are not necessarily constant over time.\ Indeed, even applying appropriate tidal correctors can be difficult. Assumptions that these issues can be resolved by having a sufficient number of independent observations (the \"wisdom of crowds\" argument) are often frustrated by\  basic physical limitations: the ocean is big, and ships are (relatively) small. Except in limited circumstances, or specific areas, the chances of having any repeated measurements are vanishingly small.
As an alternative to the collection of unqualified data which then needs to be corrected and/or qualified, we propose the use of a data collection system which, by construction, can provide sufficient guarantees of data quality as to allow the measurements to be considered for hydrographic use. We call this method Trusted Community Bathymetry (TCB).
A TCB system resolves many of the issues associated with CSB data by providing for significantly improved positioning accuracy in the vertical. High-accuracy, high-precision post-processed 3D GNSS solutions allow for the estimation of offsets between GNSS antenna and echosounder so that appropriate calibration of the system can be done autonomously. This then allows for reference of depths to a suitable ellipsoid, obviating the need to apply tidal corrections to the data.\  Given a known offset between antenna and sonar, the same techniques can be used to autonomously establish calibration sites. TCB systems also have the potential to act as a force multiplier (through cross-calibration) for other CSB efforts where calibration is lacking.
We demonstrate these ideas using a prototype TCB system developed by SeaID Ltd., which combines a NMEA data logger with a GNSS system capable of being post-processed for high-precision solutions. By comparison with survey-grade GNSS and INS systems, we demonstrate how to establish the vertical offset calibration in a system, and the construction of a calibration site. We also qualify the performance of the prototype system.
}, keywords = {Crowd-sourced Bathymetry, Ellipsoidal Survey Methods, Post-processed GNSS Solution, Trusted Community Bathymetry, Volunteered Geographic Information}, author = {Brian R Calder and Semme J Dijkstra and Shannon Hoy and Kenneth Himschoot and Andrew Schofield} } @article {6470, title = {Development of Consistent and Recordable Fusion Methods Using Bathymetry Sources of Differing Subjective Reliabilities for Navigation or Seafloor Mapping}, year = {2018}, month = {December 10-14}, pages = {Washington, DC}, abstract = {

When planning for ship navigation or compiling data for a bathymetry map, the navigator or mapper use many different sources of bathymetry information and navigation hazards. Sources include electronic charts at different scales, gridded bathymetry of different ages and quality, special purpose vector products, sonar data, crowdsourced data, etc. The quality of these sources, however, are inconsistent in general, making it especially challenging to provide a coherent picture for planning. An experienced navigator or mapper not only would use more than just the soundings, grids and depth areas to form a mental model of the seafloor, but also subjective assessment of information reliability and attitudinal character varying between optimistic/aggressive to pessimistic/conservative outlooks (or in between) depending on the purpose for the map. Here, we present an expert system approach for consistent planning/mapping that uses a combination of Bayesian and fuzzy logic processes. We present two examples of using these processes with sources of differing subjective reliabilities as follows: 1) navigation risk surface / or safety contour and 2) fusion of multiple bathymetry grids/sources for mapping. The major contribution of this process is the capability to record subjective weighting of source and the fusion process used. For the first application, we first interpolate each bathymetry source with control over the user\&$\#$39;s subjective risk allowed in the reconstruction. Each cell is set to 2, 1, or 0, for \"Known Unsafe\", \"Maybe Safe\" and \"Known Safe\" status, based on the ship\&$\#$39;s current draft. Weighted Bayesian categorical estimation (Dirichlet conjugate prior) computes a fused risk surface. The fuzzy logic process known as Order Weighted Averaging (OWA) provides the weights for each source. This component provides quantitative methods to generate, use and record subjective weights. The maximum a posteriori reconstruction for each cell provides a best estimate of status from all sources; analysis of the probability mass distribution in the cell provides guidance on reliability of the assignment. The second application uses this same process, but instead of pre-interpolation and categorical fusion, the OWA provides average bathymetry directly.

}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/393098}, author = {Paul A. Elmore and Brian R Calder and Giuseppe Masetti and Ronald R Yager and Fredrick E Petry} } @article {6469, title = {Estimating Sedimentation Rates Near Chesapeake Bay and Delmarva Peninsula and the Associated Implications for Survey Priorities}, year = {2018}, month = {December 10-14}, pages = {Washington, DC}, abstract = {

Assessing the validity of survey data and charted information over time has yet to be standardized.\  NOAA\&$\#$39;s current approach, the Hydrographic Health Model (HHM), is a risk-based methodology aimed at determining hydrographic survey priorities.\  The HHM incorporates a number of important maritime variables including heuristic changeability terms based on the seabed sedimentary material, occurrence of large storms, tidal currents, and anthropogenic obstructions.\  We propose an alternative approach that leads to a quantifiable estimate of chart health through estimation of sedimentation and erosion rates from successive bathymetric surveys, sediment cores, and numerical modeling.\  This can identify rapidly degrading regions relative to acceptable variability pre-defined using IHO standards.\  These modifications are evaluated in the central east coast of the U.S. (Chesapeake Bay and Delmarva Peninsula) where frequent hydrographic surveys are required to monitor significant sediment transport in heavily trafficked regions.\  This work not only identifies current and future survey priorities but also creates a link between hydrodynamic models and hydrographic survey priorities.

}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/460950}, author = {Cassandra Bongiovanni}, editor = {Thomas C Lippmann and Brian R Calder and Andrew A. Armstrong} } @proceedings {6471, title = {Low SNR Lidar Data Processing with Machine Learning}, year = {2018}, month = {October 1-3}, address = {St. John{\textquoteright}s, Newfoundland, Canada}, abstract = {

Advances in topo-bathymetric lidar systems now allow significantly higher data density, albeit in shallower water, than was previously possible.\  This in turn leads to opportunities for better object detection and recognition, as well as semi-automated statistical data processing.\  Design trade-offs in some of these systems can lead to many false detections, however, lowering the observation signal-to-noise ratio sufficiently to challenge any processing methodology; for the data here, having three quarters of the observations be non-bathymetric is not uncommon.

Conventional grid-based depth estimation developed for acoustic data can be successfully applied to this data in that the \“noise\” can be segregated into multiple depth hypotheses at each estimation node, but current methods for hypothesis selection fail in the face of the noise volume.

This paper proposes, therefore, an alternative scheme for depth hypothesis selection, based on machine learning techniques, that can successfully reconstruct the depth despite the levels of noise observed.\  A variant of the CHRT algorithm is first deployed to form a fine-to-coarse, data-adaptive, variable-resolution grid estimate of depth.\  A vector-quantized Hidden Markov Model (supervised) classification scheme is then used to sub-select from all hypotheses at a node only those that appear to be plausible seafloor reconstructions.\  This minimizes the reconstruction ambiguity, allowing conventional techniques to be successfully applied, while also admitting a previously unavailable \“no reconstruction\” state in areas where no depth hypothesis appears valid.\  This avoids, for example, reconstructing surface noise in areas beyond extinction depth.

The algorithm is illustrated using Reigl VQ-880-G data flown by NOAA Remote Sensing Division in 2016, which clearly demonstrates the improvement over conventional techniques.\  In addition to improved performance, lower user workload, and data fidelity, this hybrid scheme is directly compatible with current acoustically-derived algorithms, with obvious advantages for software, procedural, and training outlays that derive from a common architecture.

}, author = {Brian R Calder} } @proceedings {6348, title = {Operational TPU Software for Topobathymetric Lidar}, year = {2018}, month = {June 26-28}, address = {Providence, RI}, abstract = {

While topobathymetric lidar has been established as an effective technology for updating shoreline on nautical charts, there is great interest in the ability to simultaneously use the data to update charted depths (or \“soundings\”) in areas in areas too shallow for boats to operate safely or efficiently. However, operational use of topobathymetric lidar data in nautical charting programs requires total propagated uncertainty (TPU) models and tools comparable to those that exist for hydrographic surveys conducted with multibeam echosounders. The TPU requirement is based on the International Hydrographic Organization (IHO) \“Standards for Hydrographic Surveys\” (S-44), as well as surface generation algorithms that rely on the availability of per-point uncertainty estimates. A comprehensive TPU model has been developed for the Riegl VQ-880-G operated by NOAA\’s National Geodetic Survey (NGS). The model combines analytical uncertainty propagation for the subaerial (above water) portion and Monte Carlo simulation models for the subaqueous portion (water surface to seafloor). Because a key goal of the project is to support routine, operational use of the TPU software, computation time and ease-of-use have been important considerations in the development. The TPU model has been implemented in Python software, which is currently being tested on multiple data sets by NGS. Next steps in the project will include extending the methods to other bathymetric lidar systems.\ 

}, author = {Christopher E Parrish and Eren, Firat and J. Jung and Forfinski, Nick and Brian R Calder and White, Stephen A and Imahori, Gretchen and Kum, Jamie and Aslaksen, Michael} } @article {6239, title = {Research-driven Tools for Ocean Mappers}, volume = {22, 1}, year = {2018}, month = {Jan/Feb 2018}, pages = {29-33}, publisher = {GeoMares Publishing}, abstract = {

Fighting Repetitive, Manual and Error-Prone Routines the Smart Way.

}, keywords = {bag explorer, hydroffice, qc tools, smartmap, sound speed manager}, url = {https://www.hydro-international.com/content/article/research-driven-tools-for-ocean-mappers}, author = {Giuseppe Masetti and Matthew J. Wilson and Brian R Calder and Gallagher, B and Zhang, Chen} } @article {6101, title = {Automated Tools to Improve the Ping-to-Chart Workflow}, volume = {17}, year = {2017}, month = {May 2017}, pages = {21-30}, publisher = {International Hydrographic Bureau}, address = {Monaco}, abstract = {

The review of hydrographic and cartographic data sets is still too often based on tedious and error-prone manual actions; however, these same characteristics make the work suitable for automation. As such, a software suite of task-specific solutions was developed to support the reviewer. The specific application of these tools to NOAA Coast Survey specifications as a case study highlighted improved quality, timeliness, and user confidence in the reviewed data, and provided a training resource for new personnel. Finally, the tools drove the algorithmic interpretation of agency specifications that can establish the foundation for a fully automated workflow.

}, keywords = {automation, Data Processing, data review, quality control}, url = {https://www.iho.int/mtg_docs/IHReview/IHR_Intro.htm}, author = {Matthew J. Wilson and Giuseppe Masetti and Brian R Calder} } @article {5948, title = {Computationally Efficient Variable Resolution Depth Estimation}, volume = {106}, year = {2017}, pages = {49-59}, publisher = {Elsevier}, address = {Amsterdam, North Holland, The Netherlands}, abstract = {
A new algorithm for data-adaptive, large-scale, computationally efficient estimation of bathymetry is proposed. The algorithm uses a first pass over the observations to construct a spatially varying estimate of data density, which is then used to predict achievable estimate sample spacing for robust depth estimation across the area of interest.\ A low-resolution estimate of depth is also constructed during the first pass as a guide for further work.\ A piecewise-regular grid is then constructed following the sample spacing estimates, and accurate depth is finally estimated using the composite refined grid.\ Resource-efficient data structures allow for the algorithm to operate over large areas and large datasets without excessive compute resources; modular design allows for more complex spatial representations to be included if required. The proposed system is demonstrated on a pair of hydrographic datasets, illustrating the adaptation of the algorithm to different depth- and sensor-driven data densities.\ Although the algorithm was designed for bathymetric estimation, it could be readily used on other two dimensional scalar fields where variable data density is a driver.
}, doi = {https://doi.org/10.1016/j.cageo.2017.05.013}, url = {http://www.sciencedirect.com/science/article/pii/S0098300416306161}, author = {Brian R Calder and Glen A Rice} } @article {5947, title = {Development of an Uncertainty Propagation Equation for Scalar Fields}, volume = {40, 5}, year = {2017}, month = {August 1}, pages = {341-360}, publisher = {Taylor \& Francis Group}, abstract = {

The uncertainty of a scalar field is essential structuring information for any estimation problem. Establishing the uncertainty in a dense gridded product from sparse or random uncertainty-attributed input data is not, however, routine.\ This manuscript develops an equation that propagates the uncertainty of individual observations, arbitrarily distributed in R2, to a common estimation location at which they can be used to determine the composite uncertainty of the output field. The equation includes the effect of the distance between the observation and estimation locations, the field and horizontal uncertainty of the observation, and user-parameters to control the expected variability in the field as a function of distance. Two computational versions of the equation, a lower cost conservative approach and a higher cost mean-distance approach, are developed and evaluated for computational cost and resulting accuracy in numerical experiments over simulated bathymetric data. The mean-distance approach is more accurate, but more costly; suitable numerical approximations are proposed to control computational costs. A benefit of the work described is flexibility and enhancement for applications of the model, such as the Combined Uncertainty and Bathymetry Estimator (CUBE) algorithm, which is used as a demonstration of the difference between the two versions of the equation.

}, keywords = {bathymetry, DEM, hydrographic survey, mapping, multibeam sonar, ocean mapping}, doi = {10.1080/01490419.2017.1345811}, author = {Brian R Calder and Paul A. Elmore} } @proceedings {6058, title = {Finding Fliers: New Techniques and Metrics}, year = {2017}, month = {March 20-23}, publisher = {The Hydrographic Society of America}, address = {Galveston, TX}, abstract = {

Fliers in bathymetric grid products evidence an inaccurate portrayal of the seafloor, and must be remediated before final product creation. Traditional methods to ensure flier detection and removal are apparently not sufficient since nearly 25\% of surveys received at NOAA in 2015 had final grid deliverables affected by fliers. These grids not only require time and effort to resolve, but also compromise the lineage of the original field submission. This work describes new automated techniques for flier identification and compares their effectiveness to traditional, manual methods of flier detection. The benefits of automatic identification being statistically significant, integration of the flier identification techniques could be in the gridding algorithm is suggested as a means to reduce the rate of fliers delivered on the created surfaces.

}, keywords = {bathymetry, fliers, metrics, qc, survey}, url = {http://www.ushydro2017.com/}, author = {Matthew J. Wilson and Giuseppe Masetti and Brian R Calder} } @article {6097, title = {How to Improve the Quality and the Reproducibility for Acoustic Seafloor Characterization}, year = {2017}, month = {May 1-5}, pages = {Nova Scotia, Canada}, abstract = {

Current commercial solutions for processing acoustic data with the aim of seafloor characterization does not take full advantage of the wide spectra of information collected by modern sonars (e.g., water column data, multiple sectors). In addition, those solutions tend to act as a \‘magic black-box\’ with only a few user-defined parameters. This can be seen as an advantage (it makes these technologies available to a large community), but it also engenders a lack of data reproducibility. Currently, it is a real challenge to \‘properly\’ merge backscatter-based products from different vendors (and even from the same vendor given the lack of metadata).

In order to mitigate both issues, we developed a different approach. The proposed workflow is organized into two main phases: the first part focuses on artifact identification and reduction, while the second part is product-oriented. The artifact-oriented phase applies a (growing) set of algorithms to facilitate the identification of corrupted data so that they can then be ignored or, if required by the user, reconstructed using several different techniques. This approach also provides a metric that can then be used to identify which ping should be excluded during seafloor characterization.

The first phase is cleanly separated from the product creation. At the end of it, corrected data in the sonar\’s native format are generated together with an (optional) \‘difference\’ file (containing only the data that has been modified) and a human-readable and computer-interpretable textual description of all the applied processes. This \‘native-format\’ solution is better than converting the data to a hybrid generic data format which may not adequately preserve all of the important information from the file. The \‘difference\’ files reduce the amount of data storage since they contain only the changes, rather than doubling the storage requirement. An additional advantage is modularity. For instance, based on the kind of survey different strategies combining the identification and reduction methods can be built. Once the valid, corrected data files are created, they can be mosaicked or analyzed for seafloor characterization by the user-preferred application.

The proposed approach is demonstrated with real-world data by first using a set of bubble washdown detection algorithms, then improving the quality of the generated outputs. Specifically, the mosaic is created after the reconstruction of the corrupted samples with a weighted randomization schema, while the seafloor characterization is improved by ignoring the corrupted data.

A possible future development of this approach is to carry all the line-based descriptions of the applied processes together with the products. To make this possible in a robust way, we propose the creation of an open, community-driven product data format mimicking what has been done for bathymetric data by the Open Navigation Surface Working Group (BAG format).

}, keywords = {angular response curve, artifacts, backscatter, marianas, Seafloor Characterization}, doi = {10.4095/305398}, url = {http://geohab2017.wixsite.com/geohab2017/program}, author = {Giuseppe Masetti and Brian R Calder and Larry A Mayer} } @proceedings {6062, title = {Methods for Artifact Identification and Reduction in Acoustic Backscatter Mosaicking}, year = {2017}, month = {Marc 20-23}, publisher = {The Hydrographic Society of America}, address = {Galveston, TX}, abstract = {

Modern multibeam sonars provide high resolution measurements of acoustic backscatter that were unthinkable just a few decades ago. However, many aspects of the data acquisition can heavily impact these measurements, reducing the data quality in the output mosaic and any attempt of seafloor characterization. This work first describes techniques to identify the presence of artifacts (e.g., bubble wash-down), then explores possible scenarios for how to reduce the lack of knowledge in such areas. Finally, it outlines an approach for how to retain the information from the processing steps used in an attempt to increase output reproducibility and reusability.

}, keywords = {angular response curve, artifacts, backscatter, marianas, Seafloor Characterization}, url = {http://www.ushydro2017.com/}, author = {Giuseppe Masetti and Brian R Calder and John E. Hughes Clarke} } @article {6102, title = {Sound Speed Manager: An Open-Source Application to Manage Sound Speed Profiles}, volume = {17}, year = {2017}, month = {May 2017}, pages = {31-40}, publisher = {International Hydrographic Bureau}, address = {Monaco}, abstract = {

The execution of a modern survey using acoustic sensors cannot overlook an accurate environmental characterization of the water column. In particular, the selected sound speed profile is critical for ray tracing, while knowing the temperature and the salinity variability is crucial in the calculation of valid absorption coefficients. Built on decades of experience and feedback from hydrographic surveyors, Sound Speed Manager provides a streamlined workflow that guides the user to perform accurate processing and management of sound speed profiles. Developed following criteria of simplicity of use, robustness of results, and openness of the chosen solutions, Sound Speed Manager is a ready-for-use but customizable application, with a long-term support plan, made freely available to the hydrographic community under an open source license model.

}, keywords = {oceanography, sound speed, survey}, url = {https://www.iho.int/mtg_docs/IHReview/IHR_Intro.htm}, author = {Giuseppe Masetti and Gallagher, B and Brian R Calder and Zhang, Chen and Matthew J. Wilson} } @proceedings {6061, title = {Sound Speed Manager: An Open-Source Initiative to Streamline the Hydrographic Data Acquisition Workflow}, year = {2017}, month = {March 20-23}, publisher = {The Hydrographic Society of America}, address = {Galveston, TX}, abstract = {

The use of inaccurate sound speed data heavily affects all survey products, from the bathymetry to the backscatter mosaic to the water column imagery. Thus, sound speed profiling (SSP) is a key element for any workflow that aims to collect high-quality echosounder data. Historically, surveyors have addressed SSP using a mixture of manufacturer-specific tools, spreadsheets, scripts and some manual hacking. Far from optimal, this approach carries several disadvantages such as being error prone and inconsistent among different sound profile systems. Tools such as Velocipy, SVP Editor, and HydrOffice SSP Manager have bridged this gap, but have limitations. A new open-source tool that combines the best features of these into a single \“best of breed\” tool is here described. A joint development of NOAA Coast Survey and UNH CCOM/JHC, but open to contributions from the wider user community, Sound Speed Manager provides a route to long-term, reliable, SSP management in a convenient, readily re-distributable, flexibly licensed, form.

}, keywords = {attenuation, sound speed, survey}, url = {http://www.ushydro2017.com/}, author = {Gallagher, B and Giuseppe Masetti and Zhang, Chen and Brian R Calder and Matthew J. Wilson} } @proceedings {6114, title = {On Testing of Complex Hydrographic Data Processing Algorithms}, year = {2017}, month = {March 21-23}, publisher = {The Hydrographic Society of America}, address = {Galveston, TX}, abstract = {
Modern hydrography relies, more and more, on complex algorithms to resolve the soundings generated by remote sensing modalities, and to process those soundings into chartable products.\ Algorithm quality assurance is therefore critical to the integrity of the hydrographic effort.
At best, the algorithms used might be described in a published paper, or possibly be available as a research code-base.\ More often, however, they are integrated deep in proprietary code and cannot be tested or verified without great effort.\ For algorithms transitioned from research in one organization to operations in another, there is no guarantee that the algorithm implemented is the algorithm that was designed. And each new software release demands effectively ab initio testing effort.
Using the CHRT algorithm as an example, a testing structure is proposed.\ The structure consists of an XML-based definition which packages the required data with the desired tests, and allows for exact or approximate matching of results, with control over tolerances.\ The XML-based output provides hierarchically aggregated summaries of test success to assist in reporting with level-of-detail control.\ Although intended for end user testing, the structure has obvious benefits for developers, and acts, effectively, as the algorithm\&$\#$39;s definition: any implementation that passes the conformance suite.
}, author = {Brian R Calder and Plumlee, Matt D} } @article {6419, title = {U.S. Extended Continental Shelf Cruise to Map Necker Ridge and Vicinity, Central Pacific Ocean}, year = {2017}, month = {December 21}, pages = {69}, chapter = {Center for Coastal and Ocean Mapping/Joint Hydrographic Center}, keywords = {Law of the Sea}, author = {Andrew A. Armstrong and Brian R Calder} } @article {5924, title = {Bathymetric Terrain Model of the Atlantic Margin for Marine Geological Investigations, Version 2.0}, volume = {Version 2}, year = {2016}, month = {February 23}, pages = {17}, institution = {U.S. Geological Survey (USGS)}, address = {Woods Hole, MA}, abstract = {

A bathymetric terrain model of the Atlantic Margin covering almost 725,000 square kilometers of seafloor from the New England Seamounts in the north, to the Blake Basin in the south is compiled from existing multibeam bathymetry data for marine geological investigations. Although other terrain models of the same area are extant, they are produced from either satellite-derived bathymetry at coarse resolution (ETOPO1), or use older bathymetry data collected using a combination of single beam, and multibeam sonars (Coastal Relief Model). The new multibeam data used to produce this terrain model have been edited using hydrographic data processing software to maximize the quality, usability, and cartographic presentation of the combined 100-meter resolution grid. The final grid provides the largest, high resolution, seamless terrain model of the Atlantic Margin.

}, author = {B.D. Andrews and J.D. Chaytor and ten Brink, U.S and D. S. Brothers and James V. Gardner and Elizabeth Lobecker and Brian R Calder} } @proceedings {5826, title = {NOAA QC Tools: Origin, Development, and Future}, year = {2016}, month = {May 16 - 19}, publisher = {Canadian Hydrographic Association}, address = {Halifax, Nova Scotia, Canada}, abstract = {

Advancing multibeam technology allows us to map the seafloor better than ever before, and we have plenty of stunning bathymetry to show for it. Yet the ever-increasing data volume presents some challenges during both quality review and in its generalization to nautical chart scale. Specific challenges and inefficiencies in these processes are addressed with NOAA QC tools, specifically: 1) \"flier finder,\" which scans gridded bathymetry and flags anomalous data \"fliers\" for easy identification and removal, 2) feature scans, to ensure proper attribution and accurate representation within gridded bathymetry, and 3) an automated method of comparing survey soundings to those charted, as a formal means of chart comparison, identification of dangers to navigation, and also in the evaluation of a prospective chart sounding selection.

This paper discusses the QC tools listed above, with regards to: 1) their organic development within NOAA, to alleviate redundant, manually intensive tasks better suited for automation, 2) their implementation into the Rapid Survey Assessment (RSA) process of the NOAA Hydrographic Surveys Division (HSD), 3) their joint development with the Center for Coastal and Ocean Mapping \& Joint Hydrographic Center (CCOM/JHC) through their integration within the HydrOffice research framework, and 4) future and ongoing improvements.

Proposed innovation includes flier identification through a multi-detector algorithm, a \“smart\” chart sounding selection, and a wide range of task-specific applications to facilitate all phases of ocean mapping.

}, author = {Matthew J. Wilson and Giuseppe Masetti and Brian R Calder} } @proceedings {5825, title = {Risk Models and Survey Completeness}, year = {2016}, month = {May 16 - 19}, publisher = {Canadian Hydrographic Association}, address = {Halifax, Nova Scotia, Canada}, abstract = {

Hydrography has no well-established, mathematically rigorous, objective model for data quality. Survey effort can therefore sometimes be applied inefficiently, in that there can be as much effort expended on 1m high rocks in 30m depth as in 5m (which should be of lesser concern), or on areas where there is light to non-existent traffic. A computational model of return-on-investment associated with survey effort might allow assessment of where to survey first in a given area, and to determine when extant survey effort was \“good enough\” to meet survey specification, leading to survey efficiencies.

Mathematical models of risk associated with ship passage have previously been demonstrated as models for generalized end-user chart uncertainty, and re-survey priority estimation. Here, they are proposed as a model for survey completion which can be applied incrementally in order to rationalize the effort being applied in each area of the working grounds, and to determine when the area is sufficiently well surveyed to be considered complete.

This paper demonstrates the requirements for, and implications of, adopting such an approach for survey completeness prediction, focusing particularly on the data dependencies, and model calibration.\ The methods are illustrated with historical survey data from Hampton Roads, VA.

}, author = {Brian R Calder} } @article {5827, title = {Synoptic Risk Assessment for Ship Passage and Hydrographic Uncertainty Representation}, year = {2016}, month = {June 21 - 23}, pages = {Washington, DC}, address = {Committee on the Marine Transportation System}, abstract = {

Expression of the inherent uncertainty of hydrographic and cartographic data in chart products for surface navigation is, in general, poor.\ On most products, the only representation is a description of the age of the data (which means little to most users, and cannot be adequately assessed without detailed knowledge of when different technologies were adopted into practice), or at best some assessments such as CATZOC, which mostly describe what the hydrographers did, not what they know (or, more importantly, do not know) about the area.\ Consequently, models of ship transit risk (often in limited form, such as grounding probability or incident rate) that ignore the bathymetric component, or assume that the chart provides all available knowledge, can (potentially significantly) underestimate the effects of bathymetry on risk experienced.

As an alternative, a bathymetry-aware own-ship risk model is proposed, which accommodates presence or absence of bathymetric data, and includes such effects as measurement uncertainty, vessel parameters, and environmental variations.\ This model can be used to predict own-ship risk for specific transits in pre-voyage planning, estimate a predict-ahead uncertainty from a given position to provide real-time decision support tools, and (calibrated by AIS-derived statistical models of shipping) compute the overall risk for particular areas, which provides for an alternative statement of uncertainty in chart products that can be readily visualized even in static printed or electronic products.\ The model can also be used to assess resurvey priority, and to direct conduct of surveys.

The resulting toolset is designed as a library of risk-estimation software objects which can be configured to solve all of the described own-ship risk model estimation problems.\ The library could also be readily integrated with more general multi-ship environments to provide core risk estimation services, and readily adapts for multi-threading and multi-processing for computational efficiency.

}, author = {Brian R Calder} } @article {5928, title = {U.S. Law of the Sea Cruise to Map and Sample the US Arctic Ocean Margin, Healy 1603}, year = {2016}, month = {October 6}, pages = {135}, institution = {Center for Coastal and Ocean Mapping / Joint Hydrographic Center}, address = {University of New Hampshire, Durham, NH}, abstract = {

Healy-1603 was a relatively short cruise that was scheduled late in the year when Healy time became available due to cancellation of a BOEM cruise. Originally scheduled for 11 days, the primary objective of was to collect a few key high-resolution multibeam sonar lines in the region north of the Alaskan north slope margin and on the Beringian margin to verify and further support initial foot of the slope (FoS) picks. With the decision to use Healy for ECS operations this season, discussions also began with the Canadians with respect to a possible two-ship operation with the Louis S. St. Laurent (LSL) which was scheduled for a seismic and mapping mission in the vicinity of the North Pole and the Alpha Ridge during August and September. Logistical constraints prevented the scheduling the ships for joint operations, however, both Canada and the U.S. agreed to extend their respective cruises by five days to accommodate high-priority objectives for each other -- the LSSL would attempt to collect a seismic line on the northern extension of Chukchi Cap for the U.S. and the Healy would attempt to dredge on the southern Alpha Ridge for Canada. Thus Healy-1603 was extended five days with the added objective of dredging on the Alpha Ridge. Ancillary projects on Healy-1603 included the deployment of ice buoys under the direction of Ignatius Rigor (University of Washington) and Pablo Clemente-Col\ón (NIC) (APPENDIX G) and the real-time underway isotopic analyses of seawater samples for ocean acidification studies under the direction of Jonathan Wynn from the University of Southern Florida (APPENDIX H). NIC on board personnel also provided sea ice analysis, tactical navigation support, and daily briefings for the Healy Command and Chief Scientist.

}, keywords = {arctic, ECS, Healy, Law of the Sea}, author = {Larry A Mayer and Brian R Calder and David C Mosher} } @proceedings {5497, title = {A Bayesian marine debris detector using existing hydrographic data products}, year = {2015}, month = {May 18 - May 21}, publisher = {IEEE}, address = {Genoa, Italy}, abstract = {

Natural disasters can represent a massive source of marine debris deposition along the coastline due to strong winds, heavy rainfall, and storm surge. Such an extensive amount of debris of different size, shape, and materials could threaten navigation, natural resources, and/or human safety. After a disaster (e.g., hurricane, typhoon, tsunami, etc.), effectively and quickly processing large amounts of hydrographic data, collected using commercial systems for detection and classification of marine debris, would be highly advantageous to the necessary remediation operations. Such a task involves some degree of modeling and approximation to make the analysis computationally attractive and sufficiently effective in practice (i.e., an approximate solution with a well-structured model is preferred to an exact solution with a suboptimal model).

For this reason, a target model was built postulating a simplified description of the object properties, and a detector was specifically outlined for marine debris, detecting discrete objects which differ (e.g., protrude) from the surrounding seafloor, being close or connected to the bottom. The scope of the detector was also constrained to analyze products commonly available in existing post processing software (mainly, bathymetric digital terrain models (DTM) and backscatter mosaics with several associated data sets, such as statistics derived from the core data, or during construction) so that the technique may be quickly inserted into existing workflows, which eases resource management in a response situation.

For the backscatter mosaic, as in many existing algorithms, target detection is based on the observation that denser material (often anthropogenic) makes debris returns much stronger than the surrounding background. However, the often used approach to object detection through simple thresholding (e.g., based on the premise that on a mosaic the object return is brighter than the background) was modified since it tends to fail when the background is textured (i.e., detectors are not aware of image correlation). For the bathymetric DTM, a few spatial indices were used as proxies for any discontinuity and, thus, a possible target. For both backscatter and bathymetry, the adoption of classical estimation techniques usually generates point estimate or a confidence interval, which becomes important when fusion of target information coming from different products is attempted. In order to provide appropriate distributions for exploitation, Bayesian methods were adopted since they permit use of multiple-source asymmetric and discontinuous posterior distributions that may be carried into further analysis. A hierarchical scheme is proposed where a series of modeling tasks are implemented through a probabilistic model, casting the debris detection problem as one of estimating properties of the posterior distribution describing the probability of objects occurring given the observed data products.

The proposed model hypothesizes that the observed products are formed through observations of naturally smooth processes, modified to incorporate the presence of potential objects. Pragmatic advantages of the proposed Bayesian framework are the opportunity to include prior knowledge as well as developing an extendible robust scheme for estimating the probability of an object occurring at any point in the area of interest, making detection simpler. For instance, additional background information can be added as it becomes available. By inspection on existing nautical charts, the backscatter return far from marine debris can be approximated using a texture model or, in case the area has a geological context of large scatterers, a default model providing less informative priors.

A Markov chain Monte Carlo (MCMC) system is used to estimate probability of object presence on a per pixel/node basis. The data probability under the hypothesis of having marine debris is produced by the detector from different types of products, related both to bottom detection (depth) and to the intensity time series usually collected over it (backscatter). Together with the updated posterior probabilities, the Bayesian estimator maintains a binary detection layer. Such a layer provides a means to partially vectorize the analysis, i.e. applying prior constraints through computational geometry, and can also be used as the basis for higher-order (e.g., object-based) constraints or detection modeling.

Finally the paper provides some examples of debris detections based on the analysis of real data collected after the Super Storm Sandy event, and the detector outcomes are shown in order to evaluate the effectiveness of the proposed technique. Since the framework provides sufficient flexibility to integrate additional source of information, we are currently working on extending the detector with a set of ad hoc hydrographic products with the intent to improve the detection performance.

}, keywords = {Bayesian estimator, hierarchical model, marine debris, spatial data analysis, target detection}, url = {http://www.oceans15mtsieeegenova.org/index.cfm}, author = {Giuseppe Masetti and Brian R Calder} } @article {5180, title = {Experimental and Numerical Studies of Sound Propagation over a Submarine Canyon Northeast of Taiwan}, volume = {40(1)}, year = {2015}, month = {19 February 2014}, pages = {237-249}, publisher = {IEEE}, abstract = {

A study of sound propagation over a submarine canyon northeast of Taiwan was made using mobile acoustic sources during a joint ocean acoutic and physical oceanographic experiment in 2009.\ The acoustic signal levels (equivalently, transmission losses) are reported here, and numerical models of three-dimensional sound propagation are employed to explain the underlying phsyics.\ The data show a significant decrease in sound intensity as the source crossed over the canyon, and the numerical model provides a physical insight into this effect.\ In addition, the model suggests that reflection from the canyon seabed causes three-dimensional sound focusing when the direction of propagation is along the canyon axis.\ Environmental uncertainties of water sound speed, bottom geoacoustic properties and bathymetry are addressed, and the implications for sound propagation prediction in a complex submarine canyon environment are also discussed.

}, keywords = {3D Sound Propagation, North Mien-Hua Canyon, submarine canyons}, author = {Ying-Tsong Lin and Duda, Timothy F. and Emerson, Chris and Gawarkiewicz, Glen G. and Newhall, Arthur E. and Brian R Calder and Lynch, James F. and Abbot, Philip and Yang, Yiing-Jang and Jan, Sen} } @article {5665, title = {Hatteras Transverse Canyon, Hatteras Outer Ridge and Environs of the U.S. Atlantic Margin: A View from Multibeam Bathymetry and Backscatter}, volume = {371}, year = {2015}, month = {November 3}, pages = {18-32}, publisher = {Elsevier}, abstract = {

Previously unknown features in Hatteras Transverse Canyon and environs were recently mapped during multibeam surveys of almost the entire eastern U.S. Atlantic continental margin. The newly identified features include (1) extensive landslide scarps on the walls of Hatteras Transverse and Hatteras Canyons, (2) an area of multiple landslide deposits that block lower Hatteras Transverse Canyon, (3) a large depositional feature down-canyon from the landslide deposits that rises 100 m above the uppermost Hatteras Fan and has buried the transition from the mouth of Hatteras Transverse Canyon to uppermost Hatteras Fan, (4) a zone of cyclic steps on upper Hatteras Fan that suggests supercritical turbidity currents performed a series of hydraulic jumps and formed large upstream-migrating bedforms, (5) several knickpoints in the channel thalwegs of both Hatteras Transverse Canyon and Hatteras Canyon, one 40 m high, that suggest both canyon channels are out of equilibrium and are in the process of readjusting, either to the channel blockage by the extensive landslide deposits or by a readjustments to increased sedimentation during the last eustatic lowstand, (6) a large area of outcrop on the lower margin between Pamlico and Hatteras Canyons that previously was interpreted as an area of slumps, blocky slide debris and mud waves, (7) headward erosion in the head region of Hatteras Transverse Canyonwhere it has intercepted the lowest reaches of Albemarle Canyon channel aswell as headward erosion in a small side channel that has eroded into Hatteras Outer Ridge and (8) sections of bedforms on Hatteras Outer Ridge that are partially buried by sediment fromWashington\–Norfolk Canyon channel as well as by sediment transported fromHatteras Abyssal Plain. The newly discovered features add a new level of detail to understand the recent processes that have profoundly affected Hatteras Transverse Canyon, Hatteras Canyon and, to a lesser degree, Hatteras Outer Ridge.

}, keywords = {cyclic steps, hatteras outer ridge, Hatteras Transverse Canyon, knickpoints, landslides, upper hatteras fan}, author = {James V. Gardner and Andrew A. Armstrong and Brian R Calder} } @article {5563, title = {Huddl: the Hydrographic Universal Data Description Language}, volume = {13}, year = {2015}, month = {May 2105}, pages = {17-32}, publisher = {International Hydrographic Bureau}, address = {Monaco, Monaco Cedex, Monaco}, abstract = {

Since many of the attempts to introduce a universal hydrographic data format have failed or have been only partially successful, a different approach is proposed. Our solution is the Hydrographic Universal Data Description Language (Huddl), a descriptive XML-based language that permits the creation of a standardized description of (past, present, and future) data formats, and allows for applications like Huddler, a compiler that automatically creates drivers for data access and manipulation. Huddl also represents a powerful solution for archiving data along with their structural description, as well as for cataloguing existing format specifica-tions and their version control. Huddl is intended to be an open, community-led initiative to simplify the issues involved in hydrographic data access.

}, keywords = {compiler, database, format, huddl, huddler}, url = {http://www.iho.int/mtg_docs/IHReview/IHR_Intro.htm}, author = {Giuseppe Masetti and Brian R Calder} } @proceedings {5467, title = {Huddler: a multi-language compiler for automatically generated format-specific data drivers}, year = {2015}, month = {March 16-19}, address = {Gaylord Hotel, National Harbor, Maryland, USA}, abstract = {

The Hydrographic Universal Data Description Language (Huddl) permits description of data organization in existing and future hydrographic data formats. Huddler represents an implementation of one of the many advantages of having such format descriptions: a compiler that automatically creates drivers for data access and manipulation.

The compiler is based on an XML parsing library that loads into memory the format description (frontend), and a code generator (backend) that creates code able to access the data in three different types of computer languages: procedural ANSI C, object-oriented C++, and multi-paradigm Python. The system is designed to admit other languages readily. The compiler is accessible via command line or a GUI application, named Hush (Huddl Schema Handler), which provides additional tools and information to the user. The compiler is here demonstrated with a variety of data formats from sonar manufacturers (e.g., Kongsberg EM Series) and acquisition software companies (e.g., HyPack) both legacy and in active development, both binary and ASCII.

Finally, a community-oriented website to access, catalogue, and disseminate hydrographic data formats resources and Huddl-specific information has been developed and is now publicly available.

}, keywords = {c, c++, data formats, huddl, huddler, python, xml}, url = {http://www.ushydro.org/2015}, author = {Brian R Calder and Giuseppe Masetti} } @article {5666, title = {Marine Object Manager as Information Fusion Tool for Detected and Database-Stored Shipwrecks}, year = {2015}, month = {October 12-13}, address = {Gothenburg, Sweden}, abstract = {

The combination of information present in bathymetric and imagery-based products is a key requirement for any modern shipwreck-detection approach for areas whereas optic means cannot be adopted. \ If the data sources and the processing involved are correctly weighted in a fusion algorithm, the detection task can be extended beyond a simple binary (presence/absence) decision to provide a meaningful metric that evaluates confidence in the presence of new features. \ In combination with other existing information (e.g., Electronic Nautical Charts - ENCs), this metric can become a proxy for areas with high probability of change (for shipwrecks to be either added or removed) with respect to the baseline knowledge of the area. \ The dual, and partially contradictory, goals of such a system are to highlight areas with high probability of change, and to use the existing nautical documentation as a spatial filter to resource consumption on known features. \ Determining an appropriate balance between these is an interesting challenge.

Based on such considerations, we describe an approach for how to combine the results of different target detection algorithms, as well as in comparing such results with existing ENCs and geographic databases. \ The main goal is to help the analyst in focusing on specific areas (with higher likelihood of new features), prioritizing them on safety-of-navigation criteria and reducing the common pitfall of subjectivity in the processing workflow. \ Although mainly aimed at reducing the time required to take survey data and apply it to the chart, the approach is also well suited for different scenarios such as rapid response after hurricanes.

These concepts are tested and demonstrated by an application prototype that uses real data products, existing nautical documentation, and publicly available geospatial services to support analyst decisions.\  The application also supports a schema-based mechanism for consistent data exchange and content validation.

}, keywords = {database, pollution, risk assessment, Shipwrecks}, url = {http://www.lighthouse.nu/project/wrecks-world-iii-shipwreck-risk-assessment}, author = {Giuseppe Masetti and Brian R Calder} } @article {5643, title = {A Marine Object Manager for Detected and Database-stored Features}, year = {2015}, month = {14-18 September}, address = {Plymouth, UK}, abstract = {

The combination of information present in bathymetric and imagery-based products is a key requirement for any modern feature-detection approach that aims to be adopted in coastal areas whereas the seafloor is deep enough that optic means are not reliable. \ If the data sources and the processing involved are correctly weighted in a fusion algorithm, the detection task can be extended beyond a simple binary (presence/absence) decision to provide a meaningful metric that evaluates confidence in the presence of new features. \ In combination with other existing information (such as that present in ENCs), this metric can become a proxy for areas with high probability of change (for features to be either added or removed) with respect to the baseline knowledge of the area. \ The dual, and partially contradictory, goals of such a system are to highlight areas with high probability of change, and to use the existing nautical documentation as a spatial filter to resource consumption on known features. \ Determining an appropriate balance between these is an interesting challenge.

Based on such considerations, this work describes an approach for how to effectively assist data analysts in combining the results of different target detection algorithms, as well as in comparing such results with existing features present on ENCs and geographic databases (e.g., spatial DBMS). \ The main goal is to help the analyst in focusing on specific areas (with higher likelihood of new features), prioritizing them on safety-of-navigation criteria and reducing the common pitfall of subjectivity in the processing workflow. \ Although mainly aimed at reducing the \“ping-to-chart\” time, the approach is also well suited for different scenarios such as rapid response to the short-term increase in marine debris deposition related to major events like hurricanes and floods.

These concepts are tested and demonstrated by a Marine Object Manager application prototype that uses real acoustic data products, existing nautical documentation, and publicly available geospatial services to support analyst decisions.\  The application also supports a schema-based mechanism for consistent data exchange and content validation.

}, keywords = {hierarchical model, marine debris, spatial data analysis, target detection}, url = {http://www.shallowsurvey2015.org/?page=home}, author = {Giuseppe Masetti and Brian R Calder and Matthew J. Wilson} } @article {5548, title = {Modeling Uncertainty in Photogrammetry-Derived National Shoreline}, volume = {38(2)}, year = {2015}, month = {Dec 15, 2014}, pages = {128-145}, url = {http://www.tandfonline.com/doi/abs/10.1080/01490419.2014.957792$\#$.VSQbXE10wck}, author = {Yao, Fang and Christopher E Parrish and S. Pe{\textquoteright}eri and Brian R Calder and Yuri Rzhanov} } @proceedings {5612, title = {Multibeam Mapping of Feature Rich Seafloor in the U.S. Pacific Remote Islands Marine National Monument and on Mendocino Ridge off the California Coast}, year = {2015}, month = {March 16-19}, publisher = {The Hydrographic Society of America}, address = {National Harbor, MD}, url = {http://www.hypack.com/ushydro/2015/}, author = {Andrew A. Armstrong and James V. Gardner and Brian R Calder and Giuseppe Masetti} } @article {5276, title = {On Risk-Based Expression of Hydrographic Uncertainty}, volume = {38(2)}, year = {2015}, pages = {99-127}, publisher = {Taylor \& Francis}, abstract = {
Current methods for representing uncertainty in hydrographic products typically describe the type or completeness of data that was collected, but not the risk of transit or certainty about the data presented. This paper proposes a model for risk based on the background information, own-ship information, and how much is unknown about the area. \ Based on a model of underkeel clearance, dangers to navigation and other factors, the method predicts a scalar risk for an area, projected track or total voyage. The paper describes the risk assessment methodology, and illustrates it in track planning, area-based risk assessment and real-time decision support. \ These use cases highlight the benefits and flexibility of the model, and the concomitant requirement for clibration of input data.
}, keywords = {Bathymetric Modeling, hydrography, Own-ship Risk, Real-time Underkeel Clearance, Risk Models}, author = {Brian R Calder} } @article {5678, title = {U.S. Law of the Sea Cruise to Map the Foot of the Slope of the Northeast U.S. Atlantic Continental Margin: Leg 8}, year = {2015}, month = {September 1}, pages = {84}, institution = {University of New Hampshire}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Atlantic Margin, Law of the Sea, Marcus Langseth}, author = {Brian R Calder} } @article {5738, title = {U.S. Law of the Sea Cruise to Map the Western Flank of the Kingman Reef-Palmyra Atoll Section of the Line Islands, Equatorial Pacific Ocean}, year = {2015}, month = {December 20}, pages = {62}, institution = {Center for Coastal and Ocean Mapping / Joint Hydrographic Center}, address = {Durham, NH}, abstract = {

KM15-20 was Leg 2 of the continuing long-term bathymetric mapping of the area around Kingman Reef and Palmyra Atoll, in the equatorial Pacific. The objective of the cruise was to collect all of the bathymetric, acoustic backscatter, and sub-bottom data that might be useful to support a potential submission by the U.S. under the U.N. Convention on the Law of the Sea, Article 76 [1]. The responsibility for conducting the mapping was given to the National Oceanic and Atmospheric Administration (NOAA) by the U.S. Congress, and has been implemented since 2003 through a cooperative agreement with the Center for Coastal and Ocean Mapping and NOAA-UNH Joint Hydrographic Center at the University of New Hampshire. This cruise supplements data from a prior cruise [2] to identify the morphology of the Foot of the Slope (FoS) around the northern end of the Line Islands chain.\ 

The cruise consisted of primary bathymetric mapping in water depths of approximately 5000m using the R/V Kilo Moana (Figure 1.2), operated by the University of Hawai\‘i. The primary mapping sonar was a Kongsberg EM122 multibeam echosounder (bathymetry and acoustic backscatter), with a Knudsen Engineering 3260 chirp sub-bottom profiler, and a Bell Aerospace bgm-3 marine gravimeter. Motion measurement was provided by an ApplAnix pos/mv 320 gps-aided inertial motion unit, while sound speed profile measurements were conducted using Sippican expendable bathythermograph (xbt) and expendable conductivity, temperature and depth (XCTD) probes.

}, keywords = {kingman reef, Law of the Sea, line islands, palmyra atoll}, author = {Brian R Calder and Giuseppe Masetti} } @article {5179, title = {Assessment of Waveform Shape Features for Lidar Uncertainty Modeling in a Coastal Salt Marsh Environment}, volume = {Vol. 11, No. 2}, year = {2014}, pages = {569 - 573}, publisher = {IEEE}, abstract = {

There is currently great interest in lidar surveys of salt marshes to support coastal management and decision making. However, vertical uncertainty of lidar elevations is generally higher in salt marshes than in upland areas, and it can be difficult to empirically quantify due to the challenges of obtaining ground control in marshes. Assuming that most of the component uncertainties in the lidar geolocation equation will remain essentially constant over a relatively small location, it is posited that vertical uncertainty in a marsh will vary mostly as a function of surface and cover characteristics. These, in turn, should affect lidar waveforms recorded during the survey, and therefore, analysis of the waveform shapes may allow for prediction of vertical uncertainty variation. Waveforms at three test sites were used to compute 16 computationally efficient features that describe the shapes; and simple, multilinear, and principal component regressions were used to evaluate their ability to predict elevation differences between lidar and Global Positioning System ground control. The results show that a simple estimate of waveform width can explain over 50\% of the total variability in elevation differences but that multilinear regression does not significantly improve the performance. Somewhat surprisingly, skewness of the waveform does not appear to be a good predictor of elevation differences in these cases.

}, keywords = {Geospatial Analysis, Lasers, LIDAR, Ranging, Sea coast}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6600874}, author = {Christopher E Parrish and J Rogers and Brian R Calder} } @article {5266, title = {Development of an adaptive fusion algorithm for marine debris recognition within the post-Sandy restoration framework}, year = {2014}, month = {15-17 April 2014}, address = {St. John{\textquoteright}s, NL, Canada}, abstract = {

Recognition of marine debris represent a difficult task due to the extreme variability of the marine environment, the possible targets, and the variable skill levels of human operators. The range of potential targets is much wider than similar fields of research such as mine hunting, localization of unexploded ordnance or pipeline detection. In order to address this additional complexity, an adaptive algorithm is being developing that appropriately responds to changes in the environment, and context.

The preliminary step is to properly geometrically and radiometrically correct the collected data. Then, the core engine manages the fusion of a set of statistically- and physically-based algorithms, working at different levels (swath, beam, snippet, and pixel) and using both predictive modeling (that is, a high-frequency acoustic backscatter model) and phenomenological (e.g., digital image processing techniques) approaches. The expected outcome is the reduction of inter-algorithmic cross-correlation and, thus, the probability of false alarm. At this early stage, we provide a proof of concept showing outcomes from algorithms that dynamically adapt themselves to the depth and average backscatter level met in the surveyed environment, targeting marine debris (modeled as objects of about 1-m size).

The project relies on a modular software library, called Matador (Marine Target Detection and Object Recognition).

}, keywords = {emergency response, fusion adaptive algorithm, marine debris, target classification, target detection}, url = {http://www.chc2014.ca/}, author = {Giuseppe Masetti and Brian R Calder} } @article {5181, title = {Evaluation of Arctic Multibeam Sonar Data Using Nadir Crossover Analysis and Compilation of a Full-Resolution Data Product}, volume = {66}, year = {2014}, month = {May 2014}, pages = {228-236}, publisher = {Elsevier}, abstract = {

A new high-resolution multibeam bathymetry compilation of the Arctic Ocean-United States Arctic Multibeam Compilation (USAMBC)-was created from data available through public repositories. Much of the new data was collected through dedicated mapping cruises in support of the United States effort to map regions beyond the 200nm Exclusive Economic Zone. Data quality was evaluated using nadir beam crossover error statistics, and compiled into a high-resolution product through a weighted vertical stacking algorithm.

}, keywords = {Arctic Ocean, Cross-over Analysis, Data Compilation, Extended Continental Shelf}, url = {http://www.sciencedirect.com/science/article/pii/S0098300414000284}, author = {Flinders, Ashton F and Larry A Mayer and Brian R Calder and Andrew A. Armstrong} } @article {5267, title = {Huddl for description and archive of hydrographic binary data}, year = {2014}, month = {15-17 April 2014}, address = {St. John{\textquoteright}s, NL, Canada}, abstract = {

Many of the attempts to introduce a universal hydrographic binary data format have failed or have been only partially successful. In essence, this is because such formats either have to simplify the data to such an extent that they only support the lowest common subset of all the formats covered, or they attempt to be a superset of all formats and quickly become cumbersome. Neither choice works well in practice. This paper presents a different approach: a standardized description of (past, present and future) data formats using the Extensible Markup Language (XML). That is, XML is used to provide a structural and physical description of a data format, rather than the content of a particular file.

Done correctly, this opens the possibility of automatically generating both multi-language data parsers and documentation for format specification based on their XML descriptions, as well as providing easy version control of them. This solution provides also a powerful approach for archiving data together with their structural description, so that binary data will be easy to access in the future. Intending to provide a relatively low-effort solution to catalogue the wide range of existing formats, we suggest the creation of a catalogue of format descriptions, each of them capturing the logical and physical specifications for a given data format (with its subsequent upgrades).

A C/C++ parser code generator is used as an example prototype of one of the possible advantages of the adoption of such a hydrographic data format catalogue.

}, keywords = {binary data formats, code generator, XML catalog, XML schemas}, url = {http://hydrography.ca/chc-2014-conference.html}, author = {Giuseppe Masetti and Brian R Calder} } @article {5262, title = {A Risk Index Methodology for Potentially Polluting Marine Sites (PPMS)}, volume = {34(3)}, year = {2014}, month = {2014/05/25}, pages = {391-405}, publisher = {Springer}, abstract = {

Attempting to assess the risk of a release from a Potentially Polluting Marine Site (PPMS) can be a very subjective process. The Marine Site Risk Index (MaSiRI) is designed to provide a more objective approach to this process by adopting a table-based evaluation scheme, while still allowing for the inevitable unknown conditions by including a subjective \“expert correction\” in a suitably controlled manner.

Building on a Geographic Database (GeoDB) of PPMS records, the MaSiRI algorithm applies data filters to remove PPMS records for which it is not applicable, and then estimates a basic risk index based on core data that almost all sites would contain. It can then refine the results for those sites that have auxiliary data, varying the assessed risk as appropriate, according to standard rule-sets.

A Risk Level of Confidence (RLC) is computed and adjusted to express dynamic confidence in the risk value (e.g., due to reliance on estimates rather than measured values), and where appropriate an upper and lower bound of risk can be used to assess the range of values associated with an estimated parameter. This information can be visualized by a composite quality symbol proposed here. MaSiRI is demonstrated on three illustrative shipwrecks, and then compared against the DEEPP project database from the Pelagos Sanctuary in the western Mediterranean.

The aggregate results of the comparison are broadly similar to DEEPP, within the limits of the comparison, but provide a more detailed analysis in the case of estimated pollutant volume, and ubiquitous assessment of levels of confidence.

}, keywords = {level of confidence, PPMS, Quality Symbol, risk assessment, Risk Index}, url = {http://link.springer.com/article/10.1007/s10669-014-9504-7$\#$}, author = {Giuseppe Masetti and Brian R Calder} } @article {5014, title = {So, how deep is the Mariana Trench?}, volume = {37, No. 1}, year = {2014}, pages = {1-13}, publisher = {Geological Society of America}, address = {Boulder, CO}, author = {James V. Gardner and Andrew A. Armstrong and Brian R Calder and Beaudoin, Jonathan} } @proceedings {5296, title = {Challenges of defining uncertainty in multibeam sonar derived seafloor backscatter}, year = {2013}, month = {June 24-June 28}, address = {Corfu, Greece}, author = {Mashkoor A Malik and Larry A Mayer and Thomas C Weber and Brian R Calder and Huff, Lloyd C} } @article {5178, title = {Design of a standardized geo-database for risk monitoring of potentially polluting marine sites}, volume = {34(1)}, year = {2013}, month = {4 December 2013}, pages = {138-149}, publisher = {Springer}, address = {New York, NY, USA}, abstract = {

An increasing availability of geospatial marine data provides an opportunity for hydrographic agencies to contribute to the identification of potentially polluting marine sites (PPMS).

This new acronym has been created not only to refer to shipwrecks of modern vessels, but also for other types of marine sites such as dumping areas, pipelines, etc. Independent of the specific type, a PPMS represents a potential source of pollution for the marine environment. Although several type-specific databases are available worldwide (from local to global scale), there is an evident lack of uniformity (e.g., different aims of data collection). A common approach description of these sites at local single-site level may permit aggregation for multiscale decisions, e.g., for remediation and incident response.
To adequately manage these sites, a standardized PPMS geospatial database (GeoDB) application has been designed to collect relevant information suitable for site inventory and geo-spatial analysis. In particular, benefits in structuring the data in conformance with the Universal Hydrographic Data Model (IHO S-100) and encoding using the Geographic Markup Language (GML) are presented.

A possible practical storage solution is proposed using a GML-enabled spatial relational database management system. Finally, a Web GIS deployment is illustrated, being the simplest way to communicate to the public the collected information, with the related possibility of using the data as a Web Map Service in almost any GIS, allowing for better development and integration with other available datasets. The adoption of the PPMS GeoDB product
specification as part of the IHO S-100 series would represent an innovative and important contribution from the hydrographic community to reduce, or at least better manage, environmental and economic risks related to PPMSs.

}, keywords = {marine environment, PPMS, Risk Monitoring, shipwreck, Spatial Standard}, url = {http://link.springer.com/article/10.1007/s10669-013-9486-x?sa_campaign=email/event/articleAuthor/onlineFirst}, author = {Giuseppe Masetti and Brian R Calder} } @proceedings {5174, title = {Distribution-free, Variable Resolution Depth Estimation with Composite Uncertainty}, year = {2013}, month = {March 25-27}, publisher = {The Hydrographic Society of America}, address = {New Orleans, LA, USA}, abstract = {
Recent algorithms for processing hydrographic data have treated the problem of achievable resolution by constructing grids of fixed resolution, a composite grid of variable resolution, recursive sub-division in a quad-tree, or by relying on a comprehensive TIN of the original points. These algorithms all impose some artificial structure on the data to allow for efficient computation, however, which this paper attempts to address.
A scheme is outlined which provides a robust estimate of depth and associated uncertainty that makes as few assumptions as possible. Using a non-uniform spectral analysis, it estimates the spatial scales at which the data are consistent so it can estimate within the Nyquist limit for the underlying surface. Kernel density techniques estimate the most likely depth, and density partitioning estimates the observational and modeling uncertainty. After correcting for potential biases the uncertainty is augmented using a modified Hare-Godin-Mayer system integration uncertainty and a sound speed profile variability due to Beaudoin et al.\ The result is a robust, distribution-free, continuously variable-resolution estimate of depth with an associated uncertainty.
This algorithm is illustrated by estimating the depth (and uncertainty) of Challenger Deep, and the paper then provides some perspectives on efficiency, extensibility and adaptability of this algorithm in the hydrographic context.
}, keywords = {Bathymetric Estimation, Bias Estimation, Data Density Estimation, Data-driven Estimation, Distributed-free Depth Estimation, Lomb-Scargle Periodogram, Variable Resolution}, author = {Brian R Calder} } @article {5245, title = {Geomorphometry and processes that built Necker Ridge, central North Pacific Ocean}, volume = {346}, year = {2013}, month = {15 October 2013}, pages = {310-325}, publisher = {Elsevier}, abstract = {

Necker Ridge is an enigmatic 650-kmlong, narrow, linear aseismic bathymetric feature that rises 2500 to 3000m above the abyssal seafloor south of the Hawaiian Ridge. The ridge is the largest of a series of aseismic ridges that emanate fromthe eastern side of the Mid-PacificMountains outward towards the northeast. The trend of Necker Ridge is at an angle to fracture zones and spreading centers in the region, so its origin is controversial, yet it is a major feature on this part of the Cretaceous Pacific Plate. The entire feature, from Necker Island on the Hawaiian Ridge to the eastern Mid-Pacific Mountains, including the adjacent abyssal seafloor, was mapped in 2009 and 2011 with the latest generation of multibeam echosounders. The detailed bathymetry shows the ridge to be constructed of a series of stacked, thick (200\–400m) volcanic flows that can be traced along the trend of Necker Ridge for 100s of km. This continuity suggests that the volcanismerupted simultaneously along almost the entire length of the feature and not as spatially episodic areas of extrusion. Three relatively flat platforms occur on the summit region, presumably constructed of shallow-water carbonates when these portions of the ridge were at sea level. A conspicuous lack of thick pelagic sediment on the non-platform ridge summit and flanks is seen throughout the ridge. The lack of landslides along the length of the ridge is equally puzzling. The southern end of the ridge is connected by a saddle to the Mid-PacificMountainswhereas the northern end of the ridge is buried by an archipelagic apron of the southern flank of the Hawaiian Ridge.

}, keywords = {archipelagic apron, mid-pacific mountains, multibeam bathymetry, necker ridge, summit platform, volcanic flows, volcanic pinnacles}, author = {James V. Gardner and Brian R Calder and Mashkoor A Malik} } @proceedings {5277, title = {Gradual Generalization of Nautical Chart Contours with a Cube B-Spline Snake Model}, year = {2013}, month = {Sep 23 - Sep 26}, publisher = {IEEE}, address = {San Diego, CA, USA}, abstract = {

B-spline snake methods have been used in cartographic generalization in the past decade, particularly in the generalization of navigational charts where this method yields good results with respect to the shoal-bias rules for generalization of chart contours. However, previous studies only show generalization results at particular generalization (or scale) levels, and the user can only see two conditions: before the generalization and after generalization, but nothin in between.\ This paper presents an improved method of using B-spline snakes for generalization in the context of nautical charts, where the generalization process is done gradually, and the user can see the complete process of the generalization.

}, author = {Miao, Dandan and Brian R Calder} } @proceedings {5175, title = {Parallel and Distributed Performance of a Depth Estimation Algorithm}, year = {2013}, month = {March 25-27}, publisher = {The Hydrographic Society of America}, address = {New Orleans, LA, USA}, abstract = {
Expansion of dataset sizes and increasing complexity of processing algorithms have led to consideration of parallel and distributed implementations. The rationale for distributing the computational load may be to thin-provision computational resources, to accelerate data processing rate, or to efficiently reuse already available but otherwise idle computational resources.\ Whatever the rationale, an efficient solution of this type brings with it questions of data distribution, job partitioning, reliability, and robustness.
This paper addresses the first two of these questions in the context of a local cluster-computing environment.\ Using the CHRT depth estimator, it considers active and passive data distribution and their effect on data throughput, focusing mainly on the compromises required to maintain minimal communications requirements between nodes.\ As metric, the algorithm considers the overall computation time for a given dataset (i.e., the time lag that a user would experience), and shows that although there are significant speedups to be had by relatively simple modifications to the algorithm, there are limitations to the parallelism that can be achieved efficiently, and a balance between inter-node parallelism (i.e., multiple nodes running in parallel) and intra-node parallelism (i.e., multiple threads within one node) for most efficient utilization of available resources.
}, keywords = {Bathmetric Estimation, CHRT, Data Scheduling, Distributed Processing, Parallel Processing, Spatially-aware Data Distribution}, author = {Brian R Calder} } @article {5260, title = {Photogrammetry-Derived National Shoreline: Uncertainty and Sensitivity Analyses}, year = {2013}, month = {Dec 9-13, 2013}, address = {San Francisco, CA}, abstract = {

Tidally-referenced shoreline data serve a multitude of purposes, ranging from nautical charting, to coastal change analysis, wetland migration studies, coastal planning, resource management and emergency management. To assess the suitability of the shoreline for a particular application, end users need not only the best available shoreline, but also reliable estimates of the uncertainty in the shoreline position. NOAA\’s National Geodetic Survey (NGS) is responsible for mapping the national shoreline depicted on NOAA nautical charts. Previous studies have focused on modeling the uncertainty in NGS shoreline derived from airborne lidar data, but, to date, these methods have not been extended to aerial imagery and photogrammetric shoreline extraction methods, which remain the primary shoreline mapping methods used by NGS. The aim of this study is to develop a rigorous total propagated uncertainty (TPU) model for shoreline compiled from both tide-coordinated and non-tide-coordinated aerial imagery and compiled using photogrammetric methods. The project site encompasses the strait linking Dennys Bay, Whiting Bay and Cobscook Bay in the \“Downeast\” Maine coastal region. This area is of interest, due to the ecosystem services it provides, as well as its complex geomorphology. The region is characterized by a large tide range, strong tidal currents, numerous embayments, and coarse-sediment pocket beaches. Statistical methods were used to assess the uncertainty of shoreline in this site mapped using NGS\’s photogrammetric workflow, as well as to analyze the sensitivity of the mapped shoreline position to a variety of parameters, including elevation gradient in the intertidal zone. The TPU model developed in this work can easily be extended to other areas and may be facilitate estimation of uncertainty in inundation models and marsh migration models.

}, keywords = {photogrammetry}, author = {Yao, Fang and Christopher E Parrish and Brian R Calder and S. Pe{\textquoteright}eri and Yuri Rzhanov} } @proceedings {5176, title = {Variable Resolution Bathymetric-Gridding Technology for Nautical Charting: Case Study CHRT Data}, year = {2013}, month = {March 25-27}, publisher = {The Hydrographic Society of America}, address = {New Orleans, LA, USA}, abstract = {

This paper describes some of the tools and challenges associated with processing gridded variable-resolution bathymetry for use in nautical charting.\ Gridded data specifications for the navigation surface are ultimately dictated by the requirements for seafloor coverage and feature detection.\ It is vital to ensure that the piecewise-variable resolution of desired bathymetric content is accurately portrayed throughout the processes of visualization and product generation.\ Test data from NOAA hydrographic surveys that incorporate a variety of echo-sounder types (acoustic frequencies, beam widths) and bracket a wide range of bathymetry (depth and slope ranges, isolated features) are examined.\ Variable resolution grids are assembled from the CUBE with Hierarchical Resolution Techniques (CHRT) algorithm.\ The impact of variable resolution on bathymetric data exchange and standards thereof (BAG, S-102) is also discussed.

}, keywords = {CHRT, Hydrographic Data Processing, Nautical Charting, Variable Resolution}, author = {Lamey, B and Riley, Jack and Froelich, Grant and Miller, James and Brian R Calder} } @proceedings {4858, title = {Developing a GIS-Database and Risk Index for Potentially Polluting Marine Sites}, year = {2012}, month = {May 15 - May 17}, address = {Niagara Falls, Ontario, Canada}, abstract = {

The increasing availability of geospatial marine data provides an opportunity for hydrographic offices to contribute to the identification of \“Potentially Polluting Marine Sites\” (PPMS). These include shipwrecks, oil rigs, pipelines, and dumping areas. To adequately assess the environmental risk of these sites, relevant information must be collected and converted into a multi-scale geodatabase suitable for site inventory and geo-spatial analysis. In addition, a Risk Index \– representing an assessment of the magnitude of risk associated with any site \– can be derived to determine the potential impacts of these PPMS. However, the successful collection and integration of PPMS information requires some effort to \‘normalize\’ and standardize the data based on recognized international standards. In particular, there is benefit in structuring the data in conformance with the Universal Hydrographic Data Model (IHO S-100) recently adopted by the International Hydrographic Organization. In this paper, an S-100 compliant product specification for a PPMS geo-spatial database and associated Marine Site Risk Index is proposed which can be used by national hydrographic offices and marine protection agencies.

}, keywords = {GIS Database; Risk Index for Potentially Polluting Marine Sites; GML; PPMS; MaSiRI; shipwreck; IHO S-100}, url = {www.chc2012.ca}, author = {Giuseppe Masetti and Brian R Calder and Alexander, Lee} } @article {5036, title = {Hydrographic Data Processing on a Robust, Network-Coupled Parallel Cluster}, year = {2012}, month = {Feb 21 - Feb 26}, address = {Wellington, New Zealand}, abstract = {

Increasing data volumes and adoption of computer-assisted hydrographic data processing algorithms necessitate higher data processing rates if gains in efficiency achieved in the last decade are to be maintained and enhanced.\  Recent advances in desktop computer architectures have made multi-core and multi-processor systems readily available, and some advances have been made in implementing multi-threaded versions of common hydrographic data processing algorithms.\  In many cases, however, although the algorithms might be ideal for parallel implementation (so called \‘embarrassingly parallel\’ tasks), limitations in memory, disc and network bandwidth within a single system can have significant limitations on the scalability of these solutions.

Offloading the computational requirements to a separate, clustered system of multiple computers is therefore appealing, since it has the potential for much higher net bandwidth, and robustness, without the collateral constraints of a desktop system.\  We consider, therefore, the advantages, potential efficiency gains, and difficulties, of processing hydrographic data in a robust, network-coupled, parallel cluster of computers.\  In particular, we address the problems of efficient and robust data distribution, compute load and network balancing, and of ensuring task- and system-level robustness in such a distributed system.

To illustrate the problem, we have considered two common processing tasks: pre-processing of raw Multibeam Echosounder (MBES) data to the stage of uncertainty-attributed resolved soundings in the local level, and computation of most-probable depths with a CUBE-like algorithm.\  These tasks illustrate a time- and spatially-indexed processing problem, respectively, which can engender differences in optimal data distribution and have different data- and network-use patterns.\  We demonstrate the gains and limitations of a clustered compute solution in these two cases, using the metrics of computational time as a function of processor resources committed, and robustness of processing in the face of intermittent random failures, as applied to (portions of) the Shallow Survey 2012 Common Data Set.

}, keywords = {CHRT, Data Processing, Parallel Processing}, author = {Brian R Calder and Venugopal, Rohit} } @article {4966, title = {Hydrographic Data Processing on a Robust, Network-Coupled Parallel Cluster}, year = {2012}, month = {Feb 21 - Feb 26}, address = {Wellington, New Zealand}, keywords = {Data Processing - CUBE}, url = {http://www.conference.co.nz/shallowsurvey}, author = {Brian R Calder and Venugopal, Rohit} } @article {4987, title = {Potentially Polluting Marine Sites GeoDB: An S-100 Geospatial Database as an Effective Contribution to the Protection of the Marine Environment}, volume = {8}, year = {2012}, month = {November 2012}, pages = {27-40}, publisher = {International Hydrographic Bureau}, address = {Monaco, Monaco Cedex, Monaco}, abstract = {

Potentially Polluting Marine Sites (PPMS) are objects on, or areas of, the seabed that may release pollution in the future. A rationale for, and design of, a geospatial database to inventory and manipu-late PPMS is presented. Built as an S-100 Product Specification, it is specified through human-readable UML diagrams and implemented through machine-readable GML files, and includes auxiliary information such as pollution-control resources and potentially vulnerable sites in order to support analyses of the core data. The design and some aspects of implementation are presented, along with metadata requirements and structure, and a perspective on potential uses of the database.

}, keywords = {GML, IHO S-100, marine environment, PPMS, shipwreck, spatial SQL}, url = {http://www.iho.int/mtg_docs/IHReview/2012/IHR_November2012.pdf}, author = {Giuseppe Masetti and Brian R Calder and Alexander, Lee} } @article {5077, title = {Quality Assessment of GEBCO 08, Smith and Sandwell and SRTM30 Plus Grids in the Arctic}, year = {2012}, month = {Dec 3 - Dec 7}, address = {San Francisco, CA, United States}, abstract = {

Abs. $\#$ OS51D-1905

}, author = {Abramova, Anastasia and Monahan, Dave and Larry A Mayer and Thomas C Lippmann and Brian R Calder} } @article {4290, title = {Remote identification of a shipwreck site from MBES backscatter}, volume = {111}, year = {2012}, month = {30 November 2012}, pages = {44-52}, publisher = {Elsevier}, address = {http://ees.elsevier.com/jema/}, abstract = {

The method described attempts to remotely identify the shape of an anthropogenic object, such as a wreck of a modern vessel, using reflectivity data from Multi-Beam Echosounder (MBES) systems. In the beam domain, the backscatter strength values \– geometrically and radiometrically corrected \– are used to extract a large number of Gray Level Co-occurrence Matrix (GLCM) features with different input parameters. Principal Component Analysis (PCA) is applied in order to achieve dimensionality reduction whilst a K-means algorithm clusters as \“shipwreck site\” a large number of beams for each line. After the geo-referencing process, a K-nearest-neighbors (K-NN) technique is applied as a filter for possible misclassifications. Finally, the shape of the shipwreck site is defined from the georeferenced beams using the \α-shape method, constructing an output compatible with Geographic Information Systems (GIS).

}, keywords = {Multibeam Sonars, Seafloor Characterization}, url = {http://www.sciencedirect.com/science/article/pii/S0301479712003520}, author = {Giuseppe Masetti and Brian R Calder} } @proceedings {5052, title = {Seafloor Characterization for Trawlability Using the Simrad ME70 Multibeam Echosounder in the Gulf of Alaska}, year = {2012}, month = {May 1 - May 4}, address = {Orcas Island, WA, United States}, abstract = {

Rockfish (Sebastes spp.) stocks that associate with rugged seafloor types are difficult to assess with bottom-trawl sampling gear. Alternative methods including acoustic remote sensing and video imagery may improve rockfish assessment in untrawlable locations. Acoustic remote sensing can also be applied to quantify regions of trawlable or untrawlable seafloor and thus identify locations where alternative assessment methods may be required. We are using the Simrad ME70 multibeam echosounder (ME70), Alaska Fisheries Science Center (AFSC) trawl survey data, and video imagery to assess seafloor trawlability for locations in the Gulf of Alaska (GOA).
We surveyed areas of the GOA (20-500 m depth) using the ME70 aboard the NOAA Ship Oscar Dyson during summer 2011, from the Islands of Four Mountains, in the Aleutian Islands (169\°59\&$\#$39;0\"W 52\°43\&$\#$39;11\"N) to eastern Kodiak Island (151\°5\&$\#$39;25\"W 57\°20\&$\#$39;46\"N). Multibeam acoustic data was collected continuously along the ship trackline (1-20 nmi trackline spacing) and at fine-scale survey locations with 100\% bottom coverage (n = 21). Video data was collected at fine-scale survey sites using a drop camera to groundtruth the acoustic seafloor characterization and to identify associated fish and invertebrate species (n = 47 camera dives). At locations where historical bottom trawl hauls and 2011 camera drops were conducted, the acoustic-derived seafloor parameters that were most discriminatory in characterizing trawlable and untrawlable seafloor types were identified using a stochastic modeling approach. The extension of this approach to fish habitat characteristics will also be discussed.

}, keywords = {Seafloor Characterization; Fish Habitat; Groundfish; Bottom-trawling; Gulf of Alaska; Simrad ME70}, url = {http://geohab.org/orcasisland.html}, author = {Jodi L Pirtle and Thomas C Weber and Christopher D Wilson and Rooper, Chris and Brian R Calder} } @article {5913, title = {U.S. Law of the Sea Cruise to Map the Foot of the Slope of the Northeast U.S. Atlantic Continental Margin: Leg 7}, year = {2012}, month = {July 17}, pages = {58}, institution = {Center for Coastal and Ocean Mapping / Joint Hydrographic Center}, chapter = {Center for Coastal and Ocean Mapping/Joint Hydrographic Center}, address = {Durham, NH}, abstract = {

This report details the 2012 Atlantic Extended Continental Shelf (ECS) bathymetry mapping cruise for the U.S. Extended Continental Shelf Project. This cruise is the seventh ECS cruise to map the U.S. Atlantic continental margin. The 2012 cruise was planned after analyses of the 2004, 2005 and 2008 bathymetry demonstrated that gravity-driven down-slope transport of terrigenous sediments in some regions of the Atlantic margin extends much farther to the east than was previously documented. Consequently, the 2012 cruise focused on mapping the extent of the down-slope sediment transport at the base of the lower continental margin.

The Office of Ocean Exploration and Research, National Oceanic and Atmospheric Administration (NOAA) made available a 30-day window in the schedule of the NOAA Ship Ronald H. Brown\ for the 2012 mapping cruise. The Ronald H. Brown is an 84.5 m (274 ft) 3250 ton multipurpose oceanographic research vessel with a hull-mounted Kongsberg EM122 multibeam echo sounder (MBES).\ JHC/CCOM leased a Knudsen 3260 3.5- kHz chirp sub-bottom profiler for the cruise because the ship does not have an adequate deepwater subbottom profiler. A deep-water subbottom profiler was required to image the top 50\± m of the sediment layer to aid in the identification of deposits of sediment that have been transported by gravity (down-slope) processes.

NOAA personnel aboard the ship were responsible for system maintenance and real time data management. UNH CCOM/JHC personnel were responsible for cruise planning, a patch test of the EM122 MBES, data (MBES, subbottom and water column sound speed) collection and quality control and data processing of the MBES bathymetry and acoustic backscatter and subbottom data. The cruise collected and mapped a total area of 69,287 km2.

}, keywords = {Atlantic Margin, Law of the Sea, Ron Brown}, author = {Andrew A. Armstrong and Brian R Calder and Smith, Shep M and James V. Gardner} } @article {5037, title = {Use (and Potential Abuse) of Uncertainty in Hydrography}, year = {2012}, month = {Feb 21 - Feb 26}, address = {Wellington, New Zealand}, abstract = {

The evaluation and use of uncertainty as a component of hydrographic data processing systems has grown considerably in the last decade.\  Uncertainty models for sounding data are now common, and progress has been made in developing models, methods and implementations for preserving this uncertainty in intermediate hydrographic data products.\  Less progress has been made in dealing with expressing the uncertainty in hydrographic data products to the user, however, which we contend should be our ultimate aim.

We draw here a distinction between the uncertainty assessed for observed sounding (and auxiliary) data and uncertainty as expressed to the user, and observe that the former is at best only a component part of the latter. \ \ That is, the uncertainty of soundings describes what we observe, where the uncertainty that we might typically express to the user may be more about what we did not observe: completeness instead of accuracy.

We consider the progress in development of uncertainty models for data, and highlight a number of outstanding questions in their implementation.\  We then discuss the problem of estimating uncertainty of older data, and motivate from it an alternative model of uncertainty for user-specific hydrographic products, outlining the questions that remain to be answered for this model to be effective.\  Finally, we consider the limits of uncertainty estimation, and their implications for our ability to communicate adequate descriptions of the limits of our knowledge for users.

}, keywords = {Data Processing, Hydrographic Uncertainty, Uncertainty Estimation, Uncertainty Management}, author = {Brian R Calder} } @article {, title = {Lidar-Derived National Shoreline: Empirical and Stochastic Uncertainty Analyses}, volume = {62}, year = {2011}, pages = {62-74}, publisher = {Coastal Education \& Research Foundation, Inc. [CERF]}, address = {West Palm Beach, FL, USA}, keywords = {Data Processing}, author = {White, Stephen A and Christopher E Parrish and Brian R Calder and S. Pe{\textquoteright}eri and Yuri Rzhanov} } @article {4295, title = {Comparison and evaluation of publicly available grids in the Arctic}, year = {2011}, month = {6th Bathymetric Science Day, GEBCO}, keywords = {Deep ocean bathymetry}, url = {http://www.gebco.net/about_us/gebco_science_day/documents/gsd_2011_poster_abramova.pdf}, author = {Abramova, Anastasia and Thomas C Lippmann and Brian R Calder and Larry A Mayer and Monahan, Dave} } @proceedings {4332, title = {Design and Implementation of an Extensible Variable Resolution Bathymetric Estimator}, year = {2011}, month = {25-28 April}, address = {Tampa, FL, USA}, author = {Brian R Calder and Glen A Rice} } @article {3911, title = {U.S. Law of the Sea Cruise to Complete the Mapping of Necker Ridge, Central Pacific Ocean}, year = {2011}, pages = {1-59}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Law of the Sea}, author = {James V. Gardner and Brian R Calder} } @article {, title = {Modeling uncertainty in the lidar-derived NOAA shoreline}, year = {2010}, month = {May 25 - May 27}, chapter = {11th}, address = {Mobil, AL, USA}, keywords = {Other}, author = {Christopher E Parrish and White, Stephen A and S. Pe{\textquoteright}eri and Brian R Calder and Yuri Rzhanov} } @article {, title = {Simulating an Airborne Lidar Bathymetry}, year = {2010}, month = {May 25 - May 27}, chapter = {11th}, address = {Mobil, AL, USA}, keywords = {Other}, author = {Kumar, Amaresh M and S. Pe{\textquoteright}eri and Brian R Calder} } @article {, title = {Simulating an Airborne Lidar Bathymetry (ALB) System}, year = {2010}, month = {Jun 7 - Jun 8}, address = {Tucson, AZ, USA}, keywords = {LIDAR}, author = {S. Pe{\textquoteright}eri and Kumar, Amaresh M and Brian R Calder} } @article {, title = {Stochastic Uncertainty Analysis for Lidar-Derived Shoreline and Comparison with New Experimental Results}, year = {2010}, month = {Feb 22 - Feb 26}, chapter = {2010}, address = {Portland, OR, USA}, keywords = {Other}, author = {Christopher E Parrish and White, Stephen A and Brian R Calder and S. Pe{\textquoteright}eri} } @article {, title = {Remote Acoustic Characterization of Seafloor Properties from an AUV}, year = {2010}, month = {Feb 22 - Feb 26}, chapter = {2010}, address = {Portland, OR, USA}, keywords = {AUV \& Harbor Tracking}, author = {Arthur Trembanis and Larry A Mayer and Nicole A Raineault and Val Schmidt and Yuri Rzhanov and Brian R Calder} } @proceedings {3226, title = {New Approaches for Evaluating Lidar-Derived Shoreline}, year = {2010}, month = {Jun 6 - Jun 8}, address = {Tucson, AZ, USA}, keywords = {LIDAR}, author = {Christopher E Parrish and White, Stephen A and Brian R Calder and S. Pe{\textquoteright}eri and Yuri Rzhanov} } @article {2873, title = {Seafloor Mapping In The Arctic:Support For a Potential US Extended Continental Shelf}, volume = {3}, year = {2010}, pages = {14-23}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Law of the Sea}, author = {Larry A Mayer and Andrew A. Armstrong and Brian R Calder and James V. Gardner} } @article {3902, title = {U.S. Law of the Sea Cruise to Map the Southern Flank of the Kingman Reef-Palmyra Atoll section of the Line Islands, Equatorial Pacific Ocean}, year = {2010}, month = {June 20}, pages = {81}, institution = {Center for Coastal and Ocean Mapping / Joint Hydrographic Center}, address = {Durham, NH}, keywords = {Law of the Sea}, author = {James V. Gardner and Brian R Calder} } @proceedings {, title = {Data Density and Grid Resolution}, year = {2009}, month = {May 11 - May 14}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Glen A Rice and Brian R Calder} } @article {, title = {Estimation of Sounding Uncertainty from Measurements of Water Mass Variability}, number = {2}, year = {2009}, pages = {20-38}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Data Processing}, author = {Beaudoin, Jonathan and Brian R Calder and Hiebert, J and Imahori, Gretchen} } @proceedings {, title = {Uncertainty Wedge Analysis: Quantifying the Impact of Sparse Sound Speed Profiling Regimes on Sounding Uncertainty}, year = {2009}, month = {May 11 - May 14}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Beaudoin, Jonathan and Hiebert, J and Brian R Calder and Imahori, Gretchen} } @article {, title = {Precise Distributed Timekeeping in Hydrographic Survey}, volume = {29}, number = {8}, year = {2009}, publisher = {Flatdog Media Inc.}, address = {Frederick, MD, USA}, keywords = {Other}, author = {Brian R Calder and Brennan, Rick T and Hill, R and Lear, R} } @proceedings {, title = {Traffic Analysis for the Calibration of Risk Assessment Models}, year = {2009}, month = {May 11 - May 14}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Brian R Calder and Schwehr, Kurt} } @article {2845, title = {Angular Range Analysis of Acoustic Themes from Stanton Banks Ireland: A Link Between Visual Interpretation and Multibeam Echosounder Angular Signatures}, volume = {70}, year = {2009}, pages = {1298-1304}, publisher = {Association for Computing Machinery (ACM)}, address = {New York, NY, USA}, keywords = {Seafloor Characterization}, author = {Fonseca, Luciano and Craig Brown and Brian R Calder and Larry A Mayer and Yuri Rzhanov} } @article {, title = {High-precision, High-accuracy Timekeeping in Distributed Survey Systems}, volume = {9}, number = {1}, year = {2008}, pages = {9-24}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Sonar Capabilities}, author = {Brian R Calder and Brennan, Rick T and Marcus, J and Malzone, C and Canter, P} } @article {, title = {Approaches and Requirements of Quantitative Comparison of the Multibeam Sonar Benthic Acoustic Backscatter}, year = {2008}, month = {Oct 21 - Oct 24}, edition = {5th}, chapter = {International}, address = {Durham, NH, USA}, keywords = {Multibeam Sonars}, author = {Mashkoor A Malik and Larry A Mayer and Fonseca, Luciano and Larry G Ward and Huff, Lloyd C and Brian R Calder} } @article {3508, title = {Recent Mapping and Sampling on the Chukchi Borderland and Alpha/Medeleev Ridge}, volume = {89}, number = {53}, year = {2008}, month = {Dec 15 - 19}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Larry A Mayer and Brumley, K and Andronikov, A and Dale N Chayes and Andrew A. Armstrong and Brian R Calder and John K Hall and Clyde, W C and Bothner, W A and James V. Gardner} } @article {5000, title = {Recent Mapping and Sampling on the Chukchi Borderland and Alpha/Medeleev Ridge}, year = {2008}, month = {December 2008}, address = {San Francisco, CA, United States}, author = {Larry A Mayer}, editor = {Brumley, K} } @article {3498, title = {Uncertainty Representation in Hydrographic Surveys and Products}, year = {2008}, month = {Oct 21 - Oct 24}, edition = {5th}, chapter = {International}, address = {Durham, NH, USA}, keywords = {Data Processing}, author = {Brian R Calder} } @article {3880, title = {U.S. Law of the Sea Cruise to Map the Foot of the Slope of the Northeast U.S. Atlantic Continental Margin: Leg 6}, year = {2008}, pages = {131}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Law of the Sea}, author = {Brian R Calder and James V. Gardner} } @article {2835, title = {US UNCLOS Multibeam Data: The Processing of Multibeam Bathymetry and Backcatter}, volume = {8}, number = {9}, year = {2008}, pages = {14-17}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Law of the Sea}, author = {Andrew A. Armstrong and Brian R Calder and Fonseca, Luciano and James V. Gardner and Larry A Mayer} } @article {, title = {Drowned shelf-edge delta complexes and barrier islands and related features along the outer continental shelf north of the head of De Sotot Canyon, NE Gulf of Mexico}, volume = {89}, year = {2007}, pages = {370-390}, publisher = {Elsevier}, address = {New York, NY, USA}, keywords = {Other}, author = {James V. Gardner and Brian R Calder and John E. Hughes Clarke and Larry A Mayer and Elston, Gareth R and Yuri Rzhanov} } @proceedings {, title = {Application of High-precision Timing Systems to Distributed Survey Systems}, year = {2007}, month = {May 14 - May 18}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Brian R Calder and Brennan, Rick T and Malzone, C and Marcus, J and Canter, P} } @proceedings {, title = {Clustering Acoustic Backscatter in the Angular Response Space}, year = {2007}, month = {May 14 - May 18}, pages = {0-0}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Fonseca, Luciano and Brian R Calder} } @proceedings {, title = {High-Precision Absolute Time Synchronization in Distributed Data Capture Systems}, year = {2007}, month = {May 10 - May 11}, address = {Vancouver, British Columbia, Canada}, keywords = {Other}, author = {Brian R Calder and McLeod, M} } @article {, title = {Multi-algorithm Swath Consistency Detection for Multibeam Echosounder Data}, volume = {8}, year = {2007}, pages = {5-22}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Other}, author = {Brian R Calder} } @proceedings {, title = {CCOM Research Brief 2006}, year = {2007}, month = {May 10 - May 11}, address = {Vancouver, British Columbia, Canada}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Ultraprecise Absolute Time Synchronization for Distribute Aquisition Systems}, volume = {32}, number = {4}, year = {2007}, pages = {772-785}, publisher = {IEEE}, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Brian R Calder and McLeod, M} } @proceedings {, title = {Marine Heritage Monitoring with High Resolution Survey Tools: ScapaMAP 2001-2006}, year = {2007}, month = {May 14 - May 18}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Brian R Calder and Forbes, B and Mallace, D} } @article {, title = {Maximum A Posteriori Resampling of Noisy, Spatially Correlated Data}, volume = {7}, number = {8}, year = {2006}, pages = {1-1}, publisher = {American Geophysical Union }, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Goff, John A and Jenkins, Chris and Brian R Calder} } @proceedings {, title = {Experiments for multibeam Backscatter Adjustments on the NOAA Ship FAIRWEATHER}, year = {2006}, month = {Sep 18 - Sep 22}, pages = {0-0}, chapter = {Americas}, address = {Boston, MA, USA}, keywords = {Other}, author = {Fonseca, Luciano and Brian R Calder} } @article {, title = {High Resolution Mapping and Backscatter Studies in Support of the Ripples Program}, journal = {Journal of the Acoustical Society of America}, volume = {120}, year = {2006}, pages = {3180-3180}, publisher = {Acoustical Society of America}, address = {Melville, NY, USA}, keywords = {Other}, author = {Kraft, Barbara J and de Moustier, Christian and Brian R Calder and Larry A Mayer} } @article {, title = {CUBE User Guide}, year = {2006}, pages = {46}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {CUBE}, author = {Brian R Calder and David E Wells} } @proceedings {, title = {Uncertainty Patch Tests}, year = {2006}, month = {Jan 23 - Jan 23}, pages = {0-0}, address = {Seattle, WA, USA}, keywords = {Other}, author = {Brian R Calder} } @article {2805, title = {On the Uncertainty of Archive Hydrographic Datasets}, volume = {31}, number = {2}, year = {2006}, pages = {249-265}, publisher = {IEEE}, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {The Open Navigation Surface Project}, volume = {6}, number = {2}, year = {2005}, pages = {1-10}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Other}, author = {Brian R Calder and Shannon Byrne and Lamey, B and Brennan, Rick T and Case, James D and Fabre, D and Gallagher, B and Ladner, R W and Moggert, Friedhelm and Paton, Mark} } @proceedings {, title = {Geocoder: An Efficient Backscatter Map Constructor}, year = {2005}, month = {Mar 29 - Mar 31}, pages = {0-0}, address = {San Diego, CA, USA}, keywords = {Other}, author = {Fonseca, Luciano and Brian R Calder} } @proceedings {, title = {Adapting CUBE for Phase Measuring Bathymetric Sonars}, year = {2005}, month = {Sep 12 - Sep 15}, pages = {0-0}, edition = {4th}, address = {Plymouth, Devon, UK}, keywords = {CUBE}, author = {Hiller, R and Brian R Calder and Hogarth, P and Lindsay Gee} } @proceedings {, title = {Multibeam Swath Consistency Detection and Downhill Filtering from Alaska to Hawaii}, year = {2005}, month = {Mar 29 - Mar 31}, pages = {0-0}, address = {San Diego, CA, USA}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {On the use of historical bathymetric data to determine changes in bathymetry}, volume = {6}, number = {3}, year = {2005}, pages = {25-41}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Other}, author = {Martin Jakobsson and Andrew A. Armstrong and Brian R Calder and Huff, Lloyd C and Larry A Mayer and Larry G Ward} } @article {, title = {Multibeam Bathymetric and Sediment Profiler Evidence for Ice Grounding on the Chukchi Borderland, Arctic Ocean}, volume = {63}, year = {2005}, pages = {150-160}, publisher = {Elsevier}, address = {New York, NY, USA}, keywords = {Other}, author = {Martin Jakobsson and James V. Gardner and Vogt, Peter R and Larry A Mayer and Andrew A. Armstrong and Backman, Jan and Brennan, Rick T and Brian R Calder and John K Hall and Kraft, Barbara J} } @proceedings {, title = {Field Verification of MBES Error Models}, year = {2005}, month = {Sep 12 - Sep 15}, pages = {0-0}, edition = {4th}, address = {Plymouth, Devon, UK}, keywords = {Other}, author = {Brian R Calder and Mashkoor A Malik} } @article {, title = {High-resolution Mapping and Backscatter Studies in Support of the Ripples DRI, Ripples DRI Program}, year = {2005}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Other}, author = {Larry A Mayer and de Moustier, Christian and Kraft, Barbara J and Brian R Calder} } @article {3864, title = {New Views of the Gulf of Alaska Margin Mapped for UNCLOS Applications}, year = {2005}, pages = {2}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Law of the Sea}, author = {Larry A Mayer and James V. Gardner and Andrew A. Armstrong and Brian R Calder and Mashkoor A Malik and Angwenyi, Clive and Karlipata, Srinivas and Montoro, Hugo and Morishita, Taisei and Mustapha, Abubakar} } @article {2779, title = {Shelf-edge Deltas and Drowned Barrier-island Complexes on the Northwest Florida Outer Continental Shelf}, volume = {64}, number = {3}, year = {2005}, pages = {133-166}, publisher = {Elsevier}, address = {New York, NY, USA}, keywords = {Other}, author = {James V. Gardner and Dartnell, Peter and Larry A Mayer and John E. Hughes Clarke and Brian R Calder and Duffy, G} } @article {, title = {Security in the Open Navigation Surface Model}, year = {2004}, pages = {12}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Drowned barrier-island complexes and shelf-edge deltas on the northwest Florida outer continental self}, volume = {64}, year = {2004}, pages = {133-166}, publisher = {Elsevier}, address = {New York, NY, USA}, keywords = {Other}, author = {James V. Gardner and Dartnell, Peter and Larry A Mayer and John E. Hughes Clarke and Brian R Calder and Duffy, G} } @proceedings {, title = {Modelbased Refraction Correction in Intermediate Depth Multibeam Echosounder Survey}, year = {2004}, month = {Jul 5 - Jul 8}, pages = {795-800}, edition = {7th}, address = {Delft, Delft, The Netherlands}, keywords = {Other}, author = {Brian R Calder and Kraft, Barbara J and de Moustier, Christian and Lewis, J and Stein, P} } @proceedings {, title = {CUBE and Navigation Surface: New Approaches for Hydrographic Data Processing and Management}, year = {2004}, pages = {0-0}, address = {St. Andrews, New Brunswick, Canada}, keywords = {CUBE}, author = {Brian R Calder} } @article {, title = {DNews Configuration for Private Ship to Shore Usenet Communication}, year = {2004}, pages = {21}, institution = {National Oceanic and Atmospheric Adminiatration (NOAA)}, address = {National Ocean Service (NOS) / Office of Response and Restoration (ORR)}, keywords = {Other}, author = {Paquin, Nathan and Brian R Calder} } @article {, title = {PHB Evaluation Report on CUBE/Navigation Surface, Snow Passage, Memo for NOS}, year = {2004}, pages = {4}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {CUBE}, author = {Brian R Calder} } @article {, title = {Multibeam Error Management: New Data Processing Trends in Hydrography}, volume = {8}, year = {2004}, pages = {6-9}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Other}, author = {Hare, R and Brian R Calder and Alexander, Lee and Sebastian, S} } @proceedings {, title = {Tackling Modern Multibeam Data with CUBE}, year = {2004}, month = {Nov 22 - Nov 25}, pages = {0-0}, edition = {9th}, address = {Hamburg, Hamburg, Germany}, keywords = {CUBE}, author = {Brian R Calder} } @article {, title = {Digital Security in the Open Navigation Surface Model}, year = {2004}, pages = {12}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Tectonic Details of the Tjornes Fracture Zone, an Onshore-Offshore Ridge-transform in N-Iceland}, year = {2004}, month = {Dec 13 - Dec 17}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Brandsdottir, B and Richter, B and Riedel, C and Dahm, T and Helgadottir, G and Kjartansson, E and Detrick, R S and Magnusson, A and Asgrimmsson, A L and Palsson, B H and Karson, J and S{\textquoteright}mundsson, K and Larry A Mayer and Brian R Calder and Driscoll, Neal W} } @article {, title = {Estimation and Visualization of Seafloor Uncertainty - Annual Report}, year = {2004}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Other}, author = {Brian R Calder and Kraft, Barbara J and Larry A Mayer} } @article {, title = {A Time Comparison of Computer-Assisted and Manual Bathymetric Processing}, volume = {5}, year = {2004}, pages = {10-23}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Other}, author = {Brian R Calder and Smith, Shep M} } @proceedings {, title = {On the Uncertainty of Archive Hydrographic Datasets}, year = {2004}, month = {May 28 - May 31}, pages = {0-0}, address = {Toronto, Ontario, Canada}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Bathymetric Uncertainty Assessment}, year = {2004}, pages = {6}, institution = {Office of Naval Reasearch (ONR) }, address = {DRI}, keywords = {Other}, author = {Larry A Mayer and Brian R Calder} } @article {, title = {The Tectonic Evolution of the Tjornes Fracture Zone, Offshore Northern Iceland-ridge Jumps and Rift Propagation}, volume = {84}, number = {46}, year = {2003}, month = {Dec 8 - Dec 12}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Detrick, R S and Brandsdottir, B and Driscoll, Neal W and Richter, B and Larry A Mayer and Fornair, D and Brian R Calder and Kent, G M} } @article {, title = {Development Notes: The CCOM Implementation of CUBE}, year = {2003}, pages = {23}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {CUBE}, author = {Brian R Calder} } @proceedings {, title = {New Paradigms for Hydrographic Data Processing and Products}, year = {2003}, month = {Nov 17 - Nov 20}, pages = {0-0}, edition = {3rd}, address = {St. Andrews, New Brunswick, Canada}, keywords = {Other}, author = {Larry A Mayer and Brian R Calder and Brennan, Rick T and Lindsay Gee and Smith, Shep M and Colin Ware and Alexander, Lee and Andrew A. Armstrong and Roland Arsenault and Jurley, M and Moggert, Friedhelm and Plumlee, Matt D and Paton, Mark} } @proceedings {, title = {Electronic Chart of the Future: The Hampton Roads Project}, year = {2003}, month = {Mar 24 - Mar 27}, pages = {0-8}, address = {Biloxi, MS, USA}, keywords = {Other}, author = {Brennan, Rick T and Colin Ware and Alexander, Lee and Andrew A. Armstrong and Larry A Mayer and Huff, Lloyd C and Brian R Calder and Smith, Shep M and Plumlee, Matt D and Roland Arsenault and Glang, Gerd} } @article {, title = {How to Run CUBE (Server Processing Installation)}, year = {2003}, pages = {12}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {CUBE}, author = {Brian R Calder} } @article {, title = {Constructing Composite Chart/Bathymetry Hybrids with Fledermaus}, year = {2003}, pages = {4}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Automatic Statistical Processing of Multibeam Echosounder Data}, volume = {4}, number = {1}, year = {2003}, pages = {0-16}, publisher = {Geomatics Information \& Trading Center - GITC}, address = {Lemmers, Amsterdam, The Netherlands}, keywords = {Other}, author = {Brian R Calder} } @proceedings {, title = {The Integrated Seafloor: Efficient Multi Sensor Processing and Visualization Techniques for Seafloor Mapping Data}, year = {2003}, month = {Nov 23 - Nov 27}, pages = {0-0}, edition = {4th}, chapter = {Australasian Hydrographic Symposium}, address = {Christchurch, Christchurch, New Zealand}, keywords = {Other}, author = {Paton, Mark and Lindsay Gee and Brian R Calder and Larry A Mayer} } @proceedings {, title = {Comparison and Combination of Shallow Survey 2003 Datasets}, year = {2003}, month = {Nov 17 - Nov 20}, pages = {0-0}, edition = {3rd}, address = {St. Andrews, New Brunswick, Canada}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Lost in Iceland? Fracture Zone Complications Along the mid-Atlantic Plate Boundary}, volume = {84}, number = {46}, year = {2003}, month = {Dec 8 - Dec 12}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Brandsdottir, B and Einarsson, P and Detrick, R S and Larry A Mayer and Brian R Calder and Driscoll, Neal W and Richter, B} } @article {, title = {On Variable Resolution Grids in R}, year = {2003}, pages = {12}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {How to Run CUBE (with the Baseline CCOM/JHC Implementation)}, year = {2003}, pages = {8}, institution = {University of New Hampshire (UNH)}, address = {Center for Coastal and Ocean Mapping (CCOM)/Joint Hydrographic Center (JHC)}, keywords = {CUBE}, author = {Brian R Calder} } @proceedings {, title = {Automated and Visual Inspection Tools for Multibeam Quality Assurance and Data Analysis}, year = {2003}, month = {Nov 17 - Nov 20}, pages = {0-0}, edition = {3rd}, address = {St. Andrews, New Brunswick, Canada}, keywords = {Other}, author = {Paton, Mark and Brian R Calder and Sebastian, S} } @article {3457, title = {High-Resolution Multibeam Sonar Survey and Interactive 3-D Exploration of the D-day Wrecks off Normandy}, volume = {84}, number = {46}, year = {2003}, month = {Dec 8 - Dec 12}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Larry A Mayer and Brian R Calder and Schmidt, J S} } @proceedings {3028, title = {Providing the Third Dimension: High-resolution Multibeam Sonar as a Tool for Archaeological Investigations - An Example from the D-day Beaches of Normandy}, year = {2003}, month = {Mar 24 - Mar 27}, pages = {0-16}, address = {Biloxi, MS, USA}, keywords = {D-Day, Other}, author = {Larry A Mayer and Brian R Calder and Schmidt, J S and Malzone, C} } @proceedings {, title = {A Comparison of the Automated Navigation Surface to Traditional Smooth Sheet Compilation}, year = {2002}, month = {May 28 - May 31}, pages = {0-0}, address = {Toronto, Ontario, Canada}, keywords = {Other}, author = {Brian R Calder and Smith, Shep M} } @article {, title = {On the Estimation of Errors in Sparse Geophysical Datasets}, volume = {107}, number = {12}, year = {2002}, pages = {14-14}, publisher = {American Geophysical Union }, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Martin Jakobsson and Brian R Calder and Larry A Mayer} } @article {, title = {On the Effect of Random Errors in Gridded Bathymetric Compilations}, volume = {107}, number = {12}, year = {2002}, pages = {1-11}, publisher = {American Geophysical Union }, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Martin Jakobsson and Brian R Calder and Larry A Mayer} } @article {3410, title = {Automatic Estimation of the Seafloor Geomorphology of the Santos Basin, Brazil}, volume = {83}, number = {47}, year = {2002}, month = {Dec 6 - Dec 10}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Brian R Calder and Fonseca, Luciano and Francolin, Joao B} } @proceedings {, title = {Robust Automatic Multi-beam Bathymetric Processing}, year = {2001}, month = {May 21 - May 24}, pages = {0-20}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Brian R Calder and Larry A Mayer} } @article {, title = {Discovery of an Active Submarine Mud Volcano Along the Nootka Fault West of Vancouver Island}, volume = {82}, number = {47}, year = {2001}, month = {Dec 10 - Dec 14}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Reidel, M and Kelley, D S and Delaney, J R and Spence, G D and Hyndman, R D and Larry A Mayer and Brian R Calder and Lilley, M D and Olson, Hilary C and Schrenk, M O and Coffin, R} } @article {, title = {On the Estimation of Errors in Sparse Bathymetric Data Sets}, year = {2001}, pages = {0-31}, publisher = {American Geophysical Union }, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Martin Jakobsson and Brian R Calder and Larry A Mayer} } @article {, title = {Automatic Processing of High-rate, High-density Multibeam Echosounder Data}, volume = {4}, year = {2001}, pages = {0-24}, publisher = {American Geophysical Union }, address = {Washington DC, Washington DC, USA}, keywords = {Other}, author = {Brian R Calder and Larry A Mayer} } @proceedings {, title = {Robustness in Automatic Processing of Multibeam Echosounder Data}, year = {2001}, month = {Sep 24 - Sep 24}, pages = {0-0}, edition = {2nd}, address = {Portsmouth, NH, USA}, keywords = {Other}, author = {Brian R Calder} } @article {, title = {Automatic Processing of Bathymetric Data from Multibeam Echosounders}, volume = {82}, number = {47}, year = {2001}, month = {Dec 10 - Dec 14}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Brian R Calder} } @article {3970, title = {Automatic Processing of Bathymetric Data from Multibeam Echosounders}, year = {2001}, month = {December 10-14}, publisher = {American Geophysical Union }, address = {San Francisco, CA}, keywords = {automatic processing, bathymetric data, multibeam echosounders}, author = {Brian R Calder} } @proceedings {2972, title = {Comparing Historical and Contemporary Hydrographic Data Sets: An Example from Great Bay, New Hampshire}, year = {2001}, month = {Sep 24 - Sep 24}, pages = {0-0}, edition = {2nd}, address = {Portsmouth, NH, USA}, keywords = {Great Bay, Other}, author = {Martin Jakobsson and Andrew A. Armstrong and Brian R Calder and Larry A Mayer} } @proceedings {2974, title = {Error Estimation of Bathymetric Grid Models Derived from Historic and Contemporary Data Sets}, year = {2001}, month = {May 21 - May 24}, pages = {0-17}, address = {Norfolk, VA, USA}, keywords = {Other}, author = {Martin Jakobsson and Brian R Calder and Larry A Mayer and Andrew A. Armstrong} } @article {3972, title = {On the Estimation of Errors in Gridded Bathymetric Compilations}, year = {2001}, month = {December 10-14}, publisher = {American Geophysical Union }, address = {San Francisco, CA}, keywords = {estimation of errors, gridded bathymetric compilations}, author = {Martin Jakobsson and Brian R Calder and Larry A Mayer and Andrew A. Armstrong} } @article {3439, title = {On the Estimation of Errors in Sparse Bathymetric Geophysical Data Sets}, volume = {82}, number = {20}, year = {2001}, month = {May 29 - Jun 2}, pages = {0-0}, chapter = {Spring Meeting}, address = {Boston, MA, USA}, keywords = {Other}, author = {Martin Jakobsson and Brian R Calder and Larry A Mayer and Andrew A. Armstrong} } @article {2711, title = {Physiography and Late Quaternary-Holocene Processes of Northeastern Gulf of Mexico Outer Continental Shelf off Mississippi and Alabama}, number = {2}, year = {2001}, pages = {132-157}, publisher = {Marine Environmental Sciences Consortium of Alabama}, keywords = {Other}, author = {James V. Gardner and Dartnell, Peter and Sulak, K J and Brian R Calder and Hellequin, L} } @article {, title = {Statistical Processing of Multibeam Sonar Data from SAX-99}, volume = {81}, number = {48}, year = {2000}, month = {Dec 15 - Dec 19}, pages = {0-0}, chapter = {Fall Meeting}, address = {San Francisco, CA, USA}, keywords = {Other}, author = {Brian R Calder and Yuri Rzhanov and Fonseca, Luciano and Larry A Mayer and Flood, R D} }