Factors affecting the performance of a shipboard acoustic correlation current profiler

An RD Instruments 22 kHz acoustic correlation current profiler (ACCP) has been fitted to RRS Discovery since February 1995. Target specifications included obtaining current profiles to at least 1000 m at 4 ms^-1 and underway bottom track velocity in 4000 m. However, the results on Discovery have not lived up to all the authors´ expectations based on the instrument´s theoretical predicted performance or to the performance of the ACCP on the USS Dolphin research submarine or to the Discovery unit when installed on RDI´s small trials vessel. They have identified and quantified a number of ship-related noise sources that degraded the performance of the hull-mounted ACCP