A Chirp Scaling Algorithm for Forward-Looking Linear-Array SAR With Constant Acceleration

For forward-looking linear-array synthetic aperture radar (FLLA-SAR) with constant acceleration, the conventional hyperbolic range model is incorrect, and the range-dependent range cell migration (RCM) cannot be ignored any more. Hence, the traditional chirp scaling (CS) algorithm based on the hyperbolic range model also cannot be used. To overcome these problems, a modified range model for the FLLA-SAR which has taken the platform's acceleration into consideration is proposed in this letter. Based on the model, an improved CS method is proposed for FLLA-SAR to eliminate the space-variant characteristic of the RCM. Simulation results are presented to validate the range model and the proposed method.