An extended nonlinear chirp scaling algorithm for missile borne SAR imaging

•Extended azimuth nonlinear chirp scaling algorithm is proposed for missile borne SAR imaging.•A realistic geometry of the missile borne SAR model is built.•Thorough algorithm derivation and approximation error analysis are presented.•Numerical simulation illustrates easy implementation and high efficiency of the method.

In this paper, an extended nonlinear chirp scaling algorithm for focusing missile borne synthetic aperture radar data is proposed. Firstly, a missile borne SAR signal model is built. Then, LRWC and SRC operations are applied to mitigate the echo signal cross coupling and focus the range signal. Finally, a modified azimuth NLCS operation is used to equalize the azimuth frequency modulation rate for azimuth compression. By compensating the azimuth dependent characteristic of the azimuth FM rate and adopting higher order approximation processing, the image acquired has better accuracy and little distortion. The whole imaging procedure only consists of fast Fourier transform and complex multiplication, without interpolation, which means easier implementation and higher efficiency. The simulation results prove the accuracy and efficiency of the proposed algorithm.