Patent ID: RE43090

Claim:
A Doppler sonar flow measurement system comprising: a transducer assembly mounted on a platform wherein the transducer assembly is adapted to transmit plurality of different frequency acoustic signals underwater and then receive backscattered echoes of the acoustic signals, wherein the transducer assembly comprises a first phased array transducer transmitting at a first frequency and a second phased array transducer transmitting at a second frequency; an electronic assembly that drives the transducer assembly to generate the plurality of different frequency acoustic signals, and processes the echoes so as to determine relative velocity of underwater characteristics of a river flowing in a defined channel; and a housing assembly that houses the transducer assembly so as to reduce the disturbance of the flow of the river caused by the sonar system, wherein the first and second phased array transducers are adapted to measure underwater characteristics of the river at two different, respective, depth ranges.