Performance of a broadband acoustic Doppler current profiler

A broadband acoustic Doppler current profiler (ADCP) with enhanced performance is described. It has a useful range comparable to that of a commercially available narrowband system of the same acoustic frequency. The extra performance may be traded off among reduced velocity variance, reduced averaging time, and finer depth resolution. An expression predicting rms velocity error in terms of system parameters and the measured acoustic data is given and is shown to be consistent with the independently measured velocity error among redundant beams. The major source of bias error in narrowband ADCPs is shown to be greatly reduced for the broad band system