Open water test of the SonTek acoustic Doppler velocimeter

In June of 1994, the SonTek acoustic Doppler velocimeter (ADV) was deployed for two days from the dock at the Woods Hole Oceanographic Institution and for one day from the R/V Asterias in Buzzards Bay. The ADV was hung at a depth of approximately 2 meters below the surface. A vector averaging current meter (VMCM), used as a standard, was deployed along side. The ADV had a signal to noise of 18 to 20 dB and the velocity record is very clean with very few dropouts. During a two hour time period, 7 second averaged speeds from the two current meters had a correlation coefficient of 0.955, a mean difference of 1.8 cm s^-1 and a standard deviation of 2.1 cm s^-1. In an effort to characterize the high frequency response of the ADV, burst sample data, with sampling at 25 Hz and collected in different wave conditions, in artificially introduced bubble clouds and in the wake of the ship propeller, is examined