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Dual-Beam Interferometry for Ocean Surface Current Vector Mapping

Authors :
Frasier, Stephen J.
Camps, Adriano J.
Source :
IEEE Transactions on Geoscience and Remote Sensing. Feb, 2001, Vol. 39 Issue 2, 401
Publication Year :
2001

Abstract

The recent use of along-track interferometry (ATI) in synthetic aperture radar (SAR) has shown promise for synoptic measurement of ocean surface currents. ATI-SARs have been used to estimate wave fields, currents, and current features. This paper describes and analyzes a dual-beam along-track interferometer to provide spatially resolved vector surface velocity estimates with a single pass of an aircraft. The design employs a pair of interferometer beams, one squinted forward and one squinted aft. Each interferometric phase is sensitive to the component of surface Doppler velocity in the direction of the beam. Therefore, a proper combination of these measurements provides a vector surface velocity estimate in one pass of the aircraft. We find that precise measurements dictate widely spaced beams and that the spatial resolution for the squinted SAR is essentially identical to the sidelooking case. Practical instrument design issues are discussed, and an airborne system currently in development is described. Through computer simulation, we observe the azimuthal displacement of interferometric phases by moving surfaces identical to those of conventional SAR and find that such displacement can bias the estimated surface velocity. Index Terms--Along-track, interferometry, ocean surface currents.

Details

ISSN :
01962892
Volume :
39
Issue :
2
Database :
Gale General OneFile
Journal :
IEEE Transactions on Geoscience and Remote Sensing
Publication Type :
Academic Journal
Accession number :
edsgcl.72275784