Plan to Rescheme NOAA ENC Coverage

TitlePlan to Rescheme NOAA ENC Coverage
Publication TypeConference Abstract
AuthorsAuclert, G, Wittrock, A, Pe'eri, S, Kampia, A, Harmon, C, Nyberg, J
Conference NameU.S. Hydro Conference 2017
Conference LocationGalveston, TX
Conference DatesMarch 20 - 23

The scheme – or footprints – of NOAA ENCs are based on the footprints of the raster charts from which they were derived. As a result, changing current ENC coverage to incorporate additional survey data outside of the existing bounds is complex and poses a challenge. In addition, the scale ranges chosen for the ENC navigational usage bands differ from the International Hydrographic Organization’s (IHO) recommendations. As part of the “ENC first” effort, an ENC rescheming approach was developed to provide a seamless, tiled coverage that can easily be segmented or extended based on geographic location, available data and scale. In this new regular gridded ENC coverage approach, only a limited number of chart scales are used (down from the current 131 different scales). The new ENC scales conform to IHO S-57 and IHO S-101 ENC format specification. The new scheme segments the ENC tiles into three geographic zones. All individual ENC cell limits within each zone are along even lines of latitude and longitude. At higher latitudes, the regular longitudinal width of cells is increased twice to account for the convergence of meridians at the poles.