Abstract:
Measurements of the variation of acoustic bottom backscatter with incident angle have been made at 100 and 200 kHz at sites in Sydney Harbour, Australia, with bottom types varying from sand waves to mud. The measurements were made with transducers mounted on a rotating arm with a radius of approximately 2.4 m. Angular resolution of approximately 0.2(degrees) was achieved over a range of nearly 90(degrees). Twin cameras attached to the rotating arm allow the recording of stereo images of the bottom in favorable cases, giving a model of the scattering surface allowing a comparison of measured backscatter with that numerically estimated from surface scattering alone.