Investigating layover effects in cross-correlation based interferometry for synthetic aperture sonar

Conference: EUSAR 2018 - 12th European Conference on Synthetic Aperture Radar
06/04/2018 - 06/07/2018 at Aachen, Germany

Proceedings: EUSAR 2018

Pages: 6Language: englishTyp: PDF

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Authors:
Lorentzen, Ole Jacob; Synnes, Stig Asle Vaksvik; Hansen, Roy Edgar; Saebo, Torstein Olsmo (Norwegian Defence Research Establishment (FFI), Norway)

Abstract:
For a synthetic aperture sonar (SAS) system with two receivers displaced by a vertical baseline, interferometric processing using cross-correlation can estimate the direction of arrival and thereby the topography. The cross-correlation peak position and value are utilized for time-delay and coherence estimates. In scenes with topography which causes layover, signal interference occurs. We show examples of when more information can be extracted from the crosscorrelation function in layover regions in order to detect and measure discrepancies, both in simulations and real sonar data collected by a HUGIN autonomous underwater vehicle carrying a wideband interferometric SAS.