Velocity estimation of moving targets in SAR imaging

A new scheme is presented for velocity estimation of moving targets in synthetic aperture radar imaging. First, the moving target is imaged using a range-Doppler algorithm, where clutter lock, range correction, and focus filtering are done automatically. Then, the parameters obtained in this algorithm are used to estimate the velocity of the moving target. The Doppler centroid is used to estimate the radial velocity of the moving target, and the out-of-focus coefficient is used to estimate the cross-range velocity of the moving target. The ambiguity of the Doppler centroid is resolved according to the range-migration coefficient and the out-of-focus coefficient. This scheme is accurate and computationally efficient.