Title
Polarization Dependence of Azimuth Cutoff From Quad-Pol SAR Images
Abstract
Although basic understanding of the synthetic aperture radar (SAR) imaging mechanism of ocean waves has been achieved, challenges still remain. In this paper, a large number of quad-polarized SAR images are analyzed to help assess how the standard SAR imaging transformation applies to all polarization channels. Foremost, the azimuth cutoff, a parameter essentially governed by the detected wave motions, is today solely related to radar configuration and the ocean wave spectrum but not to the polarization configuration. As obtained, the analyses based on quad-polarized Radarsat-2 and Gaofen-3 products document the distinct dependence of azimuth cutoff on polarization and incidence angle. Especially for cross-polarized VH measurements, azimuth cutoff estimates are generally larger than copolarized HH ones, the latter already being larger than values estimated under VV configuration. This trend increases with the incidence angle. The systematic comparisons between SAR measurements and simulations further demonstrate that the present SAR nonlinear transformation may not properly take into account the differing coherence time associated with the multi-polarized observation of ocean scenes. In particular, to reproduce the large azimuth cutoff parameters of cross-polarized images, a reduced coherence time shall be expected. This measurable sensitivity shall enhance the capabilities of polarized SAR systems to precisely derive more ocean surface properties, especially the influence of wave breakers, by combining both the copolarization and cross-polarization measurements.
Year
DOI
Venue
2019
10.1109/TGRS.2019.2929835
IEEE Transactions on Geoscience and Remote Sensing
Keywords
Field
DocType
Azimuth cutoff,quad-polarization,synthetic aperture radar (SAR)
Cutoff,Remote sensing,Polarization (waves),Azimuth,Mathematics
Journal
Volume
Issue
ISSN
57
12
0196-2892
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Huimin Li1186.13
Alexis Mouche28521.13
He Wang3155.13
Justin Stopa412.71
Bertrand Chapron524452.89