A new solution to internal wave detection and parameter estimation in SAR ocean image is presented in this paper. It improves the traditional Radon transform through normalizing the Radon coefficients in an ellipse region and thus can detect the inconspicuous lines with ocean background. Making use of the idea of glide windows we use the proposed transform to detect the internal wave region

and then we can estimate the wave direction and the wavelength simply through dealing with the Radon coefficients. The experiment on real SAR images show that the proposed method can process the SAR images automatically

it can detect the internal wave region correctly and the estimated parameter is consistent to the real observation.