PROCEEDINGS OF THE IEEE FOURTH WORKING CONFERENCE ON CURRENT MEASUREMENT, pp 192-201

Deep Ocean Acoustic Doppler Current Profiling

Eric Firing¹ and R. Lee Gordon²

¹University of Hawaii at Manoa, Honolulu, HI USA

²RD Instruments, San Diego, CA, USA

A standard 300-kHz self-contained ADCP has been mounted with a CTD on a rosette sampler and used to obtain relative velocity profiles over the full ocean depth range. The unknown motion of the ADCP-CTD package is removed by averaging individual vertical shear profiles in depth bins and then integrating over the water column to get a velocity profile relative to an unknown constant of integration. The resulting profile is useful at scales of a few hundred meters, but has errors that accumulate to 10-20 cm/s over a few thousand meters. The errors are an order of magnitude larger than predicted by our simple model. More thorough error and data analysis remain to be done.