A clutter suppression method in single channel SAR image domain

Moving targets submerged in the stationary background clutter can be hardly indicated by a single channel synthetic aperture radar (SAR) system directly. In this paper, a symmetry Doppler pixel (SDP) method, which is performed on complex SAR image domain, is proposed to indicate targets for single channel SAR. Because the Doppler spectrum of clutter is symmetrically distributed in the complex SAR image domain whereas that of the targets are not, two symmetry images can be directly obtained by performing azimuth inverse Fourier transform on the positive and negative part of the Doppler spectrum of the original complex image data. In the two symmetry images, the clutter is coherent but the targets appear at different positions and have different intensities. Then, by stacking the pixels of these two symmetry images, the SDP filter is designed to minimize the clutter-pulse-noise component and keep the under test target component. Moreover, it provides more robust target indication performance when there exists pixels mis-registration between the two symmetry images.