Evaluation of AUV-based ADCP measurements

Derek A Fong, Nicole L Jones

Limnol. Oceanogr. Methods 4:58-67 (2006) | DOI: 10.4319/lom.2006.4.58

ABSTRACT: Recent development and commercialization of relatively portable and inexpensive autonomous underwater vehicles (AUVs) have led to new methods for making hydrodynamic, chemical, and biological measurements in near-coastal, lake, and estuarine systems. Equipped with Doppler velocity log (DVL) technology to allow for deadreckoning navigation, this new class of AUVs has the potential to log not only vehicle motions, but water velocities as well. In this article, we assess the performance of the DVL acoustic Doppler current profiler (ADCP) equipped on the REMUS AUV (Hydroid) in three different environments: a tidally forced lake; a wave-forced, near-shore fringing coral reef; and a gently sloping continental shelf. In all three data sets, the water velocities measured by the AUV DVL compare favorably with measurements from nearby stationary acoustic Doppler current profilers. Nevertheless, the water velocity component measured parallel to the vehicle’s tracks exhibited a bias in the direction of AUV motion, consistent with a previously reported bias found for the ship-mounted ADCP application in low-scattering environments. The fringing reef data suggest that DVLs are capable of partially resolving wave motion.