An optimized dechirping approach for moving target velocity estimation by synthetic aperture radar

In this paper, a novel algorithm for motion parameters estimation, i.e. radial and along-track velocities, of ground-moving targets by synthetic aperture radar is proposed. This algorithm transforms the conventional two-dimensional search operation into an efficient one-dimensional search operation. Thus, a significant reduction in computational load is achieved. After clutter suppression by traditional methods like Displaced Phase Center Antenna (DPCA), the remaining echoes, which belong to the moving target, represent a chirp-like behavior. Two important parameters of this inherent LFM signal, i.e. Doppler centroid frequency and Doppler rate, are estimated in an one-dimensional optimization problem of a deramping approach. These two parameters are of vital importance for image formation algorithms. Because the suitable matched filter in the azimuth compression part should be designed based on them. Performance evaluation is done by computer simulations to validate the theoretical discussions.