Estimating the velocity of moving targets in multichannel SAR images by fourier analysis and optimally-weighted velocity averaging

A scheme is developed to estimate the radial velocities of moving targets in multichannel synthetic aperture radar (SAR) images. A moving target generally consists of multiple pixels. First, a radial velocity estimate is obtained from each of these pixels via the spatial Fourier analysis, which is more robust against the clutter than the interferometry method because the target signal and the clutter are separate in the spatial frequency domain. Then, the radial velocity estimate of the moving target is obtained by a weighted averaging of the radial velocity estimates, and the weight of each radial velocity estimate is designed to minimize the mean square error (MSE) between the estimate and the truth. This optimally weighted averaging scheme is also more accurate than the optimally weighted averaging scheme related to the interferometry method, because the weight of each radial velocity estimate is designed according to the intensity of the target signal instead of the intensity of the target signal and the clutter. The effectiveness of the proposed scheme is demonstrated by the experimental results of simulated and real SAR data.