Single beam, high resolution pulse-to-pulse coherent Doppler profiler

Reports on the development of a single beam, 1.7 MHz coherent Doppler sonar. The system is PC-controlled, using a digital signal processor (DSP) to acquire and extract the velocity and backscatter amplitude data. Results from a series of tow tank calibration tests demonstrate an accuracy in the order of 5 mm s/sup -1/, for data rates of 10 profiles/second in 75, 1.5 cm range bins. The authors present data showing the systematic decorrelation of backscatter signals due to particle advection. Example observations include velocity profiles spanning the bottom boundary layer under shallow water waves.