GNSS/INS-equipped buoys for altimetry validation: lessons learnt and new directions from the Bass Strait Validation Facility
journal contributionposted on 2023-05-20, 18:06 authored by Boye ZhouBoye Zhou, Christopher WatsonChristopher Watson, Benoit LegresyBenoit Legresy, Matt KingMatt King, Jack BeardsleyJack Beardsley, Deane, A
Global Navigation Satellite System (GNSS)-equipped buoys have a fundamental role in the validation of satellite altimetry. Requirements to validate next generation altimeter missions are demanding and call for a greater understanding of the systematic errors associated with the buoy approach. In this paper, we assess the present-day buoy precision using archived data from the Bass Strait validation facility. We explore potential improvements in buoy precision by addressing two previously ignored issues: changes to buoyancy as a function of external forcing, and biases induced by platform dynamics. Our results indicate the precision of our buoy against in situ mooring data is ~15 mm, with a ~8.5 mm systematic noise floor. Investigation into the tether tension effect on buoyancy showed strong correlation between currents, wind stress and buoy-against-mooring residuals. Our initial empirical correction achieved a reduction of 5 mm in the standard deviation of the residuals, with a 51% decrease in variance over low frequency bands. Corrections associated with platform orientation from an Inertial Navigation System (INS) unit showed centimetre-level magnitude and are expected to be higher under rougher sea states. Finally, we conclude with further possible improvements to meet validation requirements for the future Surface Water Ocean Topography (SWOT) mission.
Australian Research Council
Publication titleRemote Sensing
Department/SchoolSchool of Geography, Planning and Spatial Sciences
Place of publicationSwitzerland
Rights statement© 2020 by the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/