Performance improvement for ADCPs on surface buoys

Abstract

Improvements to motion compensation in current profile data from surface buoys have been previously presented [1] and here we expand on this previous work on the integration of Attitude and Heading Reference Sensors (AHRS) to Acoustic Doppler Current Profilers (ADCP). Presently, the applicability of surface buoy-mounted ADCPs is generally limited to those applications where spatial and temporal averaging are acceptable methods to address motion concerns. However, the increasing demand from both the research and operational communities for ever finer resolution in space and time is rendering averaging as an unacceptable method for these type of deployments. But recent technological advances in miniature gyro-compensated motion sensors (improved accuracy and resolution, and reduction in physical size, power consumption, and cost) addresses some of the earlier concerns with surface buoy-mounted ADCPs. This is achieved through real-time bin mapping at the individual ping level where true tilt data is derived from the AHRS, as opposed to non-gyro-compensated tilt sensors that are the norm for ADCPs up to now. These advances allow for more precise validation of surface buoy-mounted ADCP data against static-mounted reference systems. Data from test deployments is presented, including comparison with reference systems, as well as comparison with simulated “standard” tilt sensors.