Calibration and validation of inertial measurement unit for wave resolving drifters

Abstract

We examine the performance of the Yost Engineering Incorporated 3-Space Sensor Data-Logging (TSS-DL) for use in wave resolving drifters (WRDs) that collect ocean surface wave data. We create a surface wave orbital motion simulator to test the TSS-DL in a controlled, laboratory setting at the Naval Postgraduate School. Tests are conducted in three different configurations at five frequencies within the swell and wind-sea bands. Results from the tests show that the TSS-DL can accurately resolve the vertical simulated wave motions to within37% of the analytic signal amplitude and can resolve the horizontal simulated wave motions to within2133% of the analytic signal amplitude. We further examine some field data collected using the TSS-DL onboard WRDs deployed in June 2013 near the mouth of the Columbia River. This analysis, based on comparison with independent GPS wave measurements, demonstrates that the TSS-DL yields reliable estimates of surface wave spectra and can track surface wave profiles even under extreme conditions with large breaking waves. Overall, this study shows that the TSS-DL is a suitable sensor for use in ocean surface drifters to accurately record surface waves.