Spotlight SAR squinted model sub-aperture chirp scaling algorithm

The article presents a spotlight SAR imaging algorithm for large scenes. Based on the classical chirp scaling algorithm, the algorithm divides the datum into several sub-apertures to image. Squinted equivalent range model is used. Range scaling is combined with range compression. Rational scaling factor is selected to remove the difference of sub-apertures. Phase compensatory factor is amended to make azimuth time outstanding. After azimuth compression, the sub-apertures are arrayed and synthesized to offer a full-aperture resolution image. Validity of the algorithm is testified by computer simulations.