THE MEASUREMENT OF TWO-DIMENSIONAL BOTTOM BACKSCATTERING COEFFICIENTS AT SHALLOW WATER

A frame with ten transducers, s paced vertically in the intervals of 0.5 m, was mounted on the sea bottom to measure the monostatic and bistatic backscattering from the sea floor. The bottom was sandy silt and the water depth was about 63 m. By turns, one of these transducers transmitted sound pulses with the frequency of 10 kHz and the rest （or the same one） received the signals scattered from the bottom. In this way, the bottom backscattering coefficients were measured as a function of both incident and scattering grazing angles （0.6°-40°）. Meanwhile, the bottom reflection coefficient and reverberation intensities were also measured in the same area under the condition of thermocline. By feeding the measured bottom scattering and reflection coefficients as well as the sound-speed profile into the model of reverberation Zhang Ren-he and Jin Guo-liang, Acta Acustica, 9,（1984）, 12-19, we have estimated the reverberation intensities which are in good agreement with the measured data.