240-kHz bistatic bottom scattering measurements in shallow water

High-frequency bistatic sediment scattering experiment was conducted in the shallow waters off the east coasts of Korea. Acoustic data were taken as a function of grazing angle (30/spl deg/, 45/spl deg/, and 60/spl deg/), scattered angle (30/spl deg/, 45/spl deg/, and 60/spl deg/), and bistatic (azimuthal) angle (0/spl deg/, 60/spl deg/, and 120/spl deg/). Besides a flat bottom it was artificially raked so as to produce directional ripples. The measured scattering strengths for a flat bottom were compared to model predictions of D.R. Jackson et al. (1986). The surface reverberation component is seen to dominate over the volume scattering part at the frequency of 240 kHz. Compared to the flat bottom case, the scattering strengths for directional ripples showed lower and higher variation depending on the ripple's orientation.