Further Development in the Doppler Method of Water-Velocity Measurement

A Doppler current meter was developed to provide an instrument for the measurement of water-flow velocity. This type of instrument detects the Doppler frequency shift which occurs in the acoustic signal received from reflections from moving microscopic particles in water which are excited by an acoustic beam of high-frequency energy. Mechanical inertias are minimal and there are no moving parts, so high accuracy is possible even under transient conditions. A test facility was designed to determine the instrument accuracy. Certain unusual phenomena were revealed.