DOPPLER SONAR MEASUREMENTS OF OCEAN WAVES AND CURRENTS

Recently Doppler sonars have been developed for the remote measurement of oceanic flows. This paper outlines the operating principles of these devices, and illustrates their present capabilities. Two classes of sonar are discussed. Pulse-to-pulse coherent sonar systems sense water motion using the change in echo phase from one pulses to the next at fixed range. Incoherent sonars are of use in measuring motions which change but slowly in space and time. Both types of sonar systems are ideal for Arctic use, where the depolyment of moorings is difficult, and the potential for ice damage encourages portable systems.