ADCP - Acoustic Doppler Current Profiler

 

An Acoustic Doppler Current Profiler (ADCP) is a hydroacoustic current meter similar to a sonar, attempting to measure water current velocities over a depth range using the Doppler effect of sound waves scattered back from particles within the water column. ADCPs contain piezoelectric oscillators to transmit and receive sound signals. The traveling time of sound waves gives an estimate of the distance, the red or blue shift can be converted to a velocity. To measure 3D velocities, at least three vector components have to be estimated, this is why the instrument typically has four of them.