Theoretical expression for an ocean internal soliton synthetic aperture radar image and determination of the soliton characteristic half width

Abstract

This paper deals with the development of techniques for satellite synthetic aperture radar (SAR) ocean image interpretation. We derived a theoretical model of a radar image for a Korteweg‐de Vries type ocean internal soliton and validated the model using ocean internal wave signals taken from ERS‐1 SAR and RADARSAT SAR images. The results indicate that the model perfectly simulates ocean internal soliton signatures with double‐sign variations of radar backscatter. On the basis of the model, we developed the curve fitting method and the peak‐to‐peak method for determining the internal soliton characteristic half widths, which then were used to calculate the internal soliton amplitudes. The test results indicate that ocean internal soliton amplitudes derived by the two methods agree with in situ data acquired on the Portuguese Continental Shelf and in the South China Sea with reasonable accuracy. The role that wind fields play in ocean radar remote sensing was also analyzed. Finally, the modulation ratio of ocean internal waves on radar images was quantitatively estimated.