Sea Trials of a Lowered, Three-Axis Current Meter

Results of sea trials for a prototype over-the-side three-axis current meter/CTD are reported. The instrument is novel in that it measures three components of velocity, of acceleration and of magnetometic field, thus enabling conversion of the measured velocity into earth coordinates. Suitable processing of the accelerometer data also permits the measured velocity to be corrected for short-period instrument motions induced by the ship. The tests reported here indicate that the technique can measure currents relative to the mean ship drift with an error of order 1 cm/sec in a variety of sea states.