Retrieving internal wave surface currents from SAR image
SAR海洋内波表层流反演方法探讨

Based on ocean internal wave Synthetic Aperture Radar (SAR) imaging mechanism and the M4S model, which was applied to simulate the oceanic features of ocean surface, one new method for retrieving internal wave surface currents from SAR image is introduced. Firstly, according to the AH linear theory, the first guessed surface currents could be estimated from the normalized radar crossing section (NRCS) of the internal wave profile in SAR image, and the signal induced by internal wave surface currents can be simulated by M4S. Then the wind speed and internal wave surface currents gradients are modified using the dichotomy method step by step, which causes the simulated signal close to the NRCS measured from SAR image. Finally, the wind speed and the surface currents could be retrieved until a satisfied match between the simulated signals and SAR images. This method is tested on three ERS-2 SAR images in the South China Sea. The results show that the simulated internal wave signal is consistent with the NRCS of internal wave SAR images. Their correlation coefficients are up to 90%, which indicate that this method is convergent and applicable.