A modified Omega-K algorithm for squint circular trace scanning SAR using improved range model

Abstract

Abstract For squint circular trace scanning SAR (CTSSAR), the circular flight trajectory and squint angle make the conventional hyperbolic range model (CHRM) hard to accurately represent the true range history. Traditional frequency domain algorithms cannot accomplish precise imaging directly. To address this problem, a modified Omega-K algorithm with improved range model is proposed. The algorithm can be divided into two main steps: Range-independent error compensation and range-dependent error compensation. By employing the improved range model, the complex coarse range-independent range phase error is compensated. Then the omega-K algorithm is implemented to remove the residual range-dependent phase error for target focusing. Simulation results validate the effectiveness of the proposed range model together with the imaging algorithm.