Multiping Multibeam Echo-Sounding Using Time-Frequency Coded Waveform Sets
Existing commercial wideband multiping multibeam echo-sounders increase the along-track sounding density by transmitting multiple pings in separate bandwidth channels. These systems utilize multiple transducer arrays which inherently cost more to produce. The same increase in along-track sounding density can be achieved using existing bandwidth more effectively, increasing the complexity of the system instead of the manufacturing cost. Simply increasing the ping rate in a single bandwidth channel causes two-way travel time ambiguity. We propose a system in which this is resolved by time-frequency coding the pings. The increased ping rate also causes receiver blanking to occur whenever pings are transmitted, and some of the additional seafloor detections are missed. However, the number of soundings lost from receiver blanking is small relative to the overall increase that is a result of transmitting multiple pings so that a net gain is still achieved.
Brian O’Donnell is a Ph.D. student in the Electrical Engineering Department at the University of New Hampshire. His Ph.D. research is the system design and testing of a multiping multbeam echo sounder. He received his M.S. in Electrical Engineering from the University of New Hampshire in 2009 and his B.S. in Electrical Engineering from Worcester Polytechnic Institute in 2005.