Synthetic Aperture Sonar Multi-aspect Differential Interferometry for Detection of Internal Waves

Conference: EUSAR 2022 - 14th European Conference on Synthetic Aperture Radar
07/25/2022 - 07/27/2022 at Leipzig, Germany

Proceedings: EUSAR 2022

Pages: 6Language: englishTyp: PDF

Authors:
Saeboa, Torstein Olsmo (Norwegian Defence Research Establishment (FFI), Kjeller, Norway)
Hansen, Roy Edgar (Norwegian Defence Research Establishment (FFI), Kjeller, Norway & University of Oslo, Department of Informatics, Oslo, Norway)
Lyons, Anthony (Center for Coastal & Ocean Mapping, Jere A. Chase Ocean Engineering Lab, Durham, NH, USA)

Abstract:
Refractive effects due to breaking internal waves can be present in synthetic aperture sonar (SAS) images and SAS bathymetries. These effects cause large linear structures (tens of meters by several meters) in the SAS images and may be misinterpreted as actual bathymetric features on the seafloor. Such misinterpretations limit our ability to acquire accurate knowledge of the seafloor and are therefore important to resolve. Detection of internal waves in SAS images using repeated passes has been suggested, but a robust detection method for single passes is still missing in the literature. We suggest a novel method which uses multi-aspect differential interferometry to detect these features caused by refractive effects. We present results from the MANEX’13 experiment, where internal wave effects where present in the SAS data and originally detected using multiple passes. We also include a reference dataset from outside Horten, Norway, where there are no indications of internal waves.