Current Measurement Showdown: Workhorse 300 vs Signature 55 vs MAVS

Daniel J Torres1, Kurt L Polzin2, Susan Wjiffels1, Gunnar Voet3, Matthew Alford3 and Brian Hogue4, (1)Woods Hole Oceanographic Institution, Woods Hole, MA, United States, (2)WHOI, Woods Hole, MA, United States, (3)Scripps Institution of Oceanography, La Jolla, CA, United States, (4)Woods Hole Oceanographic Institution, United States
An experimental mooring was designed in order to test the performance of three different velocity measuring devices. The mooring, deployed at the 1100m isobath at 32o 36.3 N, 117 o 27.5 W near the San Diego Trough, consisted of an upward facing Nortek Signature 55 (Sig55) current profiler deployed at 1090m depth, a downward facing Teledyne RD Instruments 300 kHz Workhorse ADCP deployed at 900 m depth, and a string of five NOBSKA Modular Acoustic Velocity Sensors (MAVS) deployed at discrete depths between 900m – 1100m. The MAVS is an acoustic travel time point-measurement current meter that in many respects is equivalent to an acoustic anemometer used in atmospheric boundary layer turbulence studies. It has a 10 cm cube sensing volume and an intrinsic sensitivity of 0.3 mm/s. We have evaluated the current measurement performance of the Sig55 and the MAVS current meter against the Workhorse ADCP. Additionally, we evaluated the range and power consumption of the Sig55 against manufacture stated specifications. Presented here are the results of those comparisons over a 60-day deployment period.