Calibration of acoustic Doppler current profiles

The National Ocean Service of NOAA has recently conducted tests and established a laboratory calibration technique for Doppler current profilers. A cooperative effort was established with the manufacturer to assess the technique and the instrument's performance. Several systems ranging in operating frequencies from 300 to 1200 kHz were tested and calibrated. A 1200-kHz system was characterized by the manufacturer through a series of laboratory tests and evaluation runs on a calibrated lake course. This unit was then tested by NOAA for comparison purposes. Calibrations of both bottom track and water track velocity were performed at speeds from 0 to 300 cm/s. Sources of error were investigated by NOAA and the manufacturer. Test results, calibration data, and procedures are discussed.<>