Sonar watermark embedding and detection: a sea trial report

This paper reports on performance of a previously reported sonar watermarking algorithm in actual sea trials. Tests were conducted at the South Florida Ocean Measurement Facility in shallow water depths of 200m and a range of 7km subject to a 80dB propagation loss. The watermark was designed to match the acoustic channel simulated in the Sonar Simulation Toolset (SST), but no access to the actual acoustic channel was available prior to the test. Watermark detection was carried out over multiple ping cycles. For a 10-ping cycle, it was possible to achieve zero false alarm and a single miss at SWR=27dB. At SWR=30dB, zero false alarm was maintained but the miss rate increased to three. This experiment has rearmed the detectability of the watermark in actual sea deployment.