The performance of an acoustic Doppler velocimeter (ADV) was evaluated usin
g a towing tank. Rudimentary tests of the speed response were followed by t
ests of yaw and pitch response. Because only a few published land inconsist
ent values of sound speed as a function of saltwater concentration were fou
nd, a simple scheme was devised using the boundary-detection feature of the
ADV to obtain such values. Tests were also run in the stratified tank to v
erify the usability of the ADV there. The accuracy of the probe to horizont
al flow fields is generally within the range of +/-0.25% +/-0.25 cm/s, and
the yaw response is very nearly sinusoidal. Limited pitch-response tests su
ggested an indicated overspeed of some 5-10% for horizontal velocities and
an indicated underspeed of 5-15% for vertical velocities. A correction sche
me was developed to allow the ADV to be used in high-concentration saltwate
r, and its suitability was verified in homogeneous saltwater solutions. Whe
n the same scheme was used in a strongly stratified tank, however, a small
overcorrection was indicated. Tests on a new probe design suggested much im
proved pitch response.