Acoustic Doppler Current Profiler to Measure Current Velocity

摘要

Doppler speed log, an instrument that measures the speed of ships through the water or over the sea bottom was used before adcp. The first ADCP which was commercial, was based on concept of a commercial speed log . The speed log was refabricated to measure water velocity more precisely and to allow measurement in range cells over a depth profile. Henceforth, the first vessel-mounted ADCP was made. TRDI produced its first ADCP, a self-contained instrument designed for use in long-term in 1982. TRDI produced its first vessel-mounted ADCP In 1983. By 1986, TRDI had made five different frequencies (75-1200 kHz) and three different ADCP models (self-contained, vesselmounted, and direct-reading). The concept of Doppler signal processing has established itself with the instruments afterwards. Speed logs used relatively simple processing with phase locked loops. The first generation of ADCPs used a narrow-bandwidth, single-pulse, autocorrelation method that computes the first moment of the Doppler frequency spectrum. This method was the first to produce water velocity measurements with sufficient quality for use by oceanographers.