Bottom/subbottom surveying using a new, parametric, sidescan sonar
The Naval Research Laboratory (NRL) has developed a dual-frequency, towed, interferometric, sidescan sonar system known as the Subbottom Swath System, which is capable of detecting objects and structures buried below the sea floor. The transducer geometry is that of a conventional interferometer side scan sonar system but with a more powerful (241 dB re I @a @ Im) source. As a result of this power, s3 is capable of generating low frequency (500 Hz - 2 kHz) parametric signals (-203 dB re I @a @ lm for 1600 Hz) that can easily penetrate several meters to tens of meters into the bottom. Datafrom a test in Puget Sound, WA show evidence of bottom penetration of parametrically generated sound.
SourceIn: High Frequency Seafloor Acoustics (SACLANTCEN Conference Proceedings CP-45), 1997, pp. 607-612
Wood, Warren T.;
Gettrust, Joseph F.;
Sen, Mrinal K.;
Kosalas, James G.