A simulator for spotlight SAR image formation

In this paper, a simulator for spotlight SAR image formation is presented. The simulator produces radar returns from a simulated aircraft positioned at an arbitrary distance and altitude. The radar returns are produced from an image, where the return is a summation of chirp signals delayed by the distance of each pixel in the image to the aircraft. Range profiles are formed from the returns via stretch processing or by demodulation and matched filtering of the return signals. Finally, the simulated SAR images are formed by a summed back projection of each of the range profiles. The significance of producing radar returns from an image, is that the resulting SAR data can be directly compared to an original image with tradition image processing metrics. The simulator shows that both stretch processing and matched filtering produce good imagery, with stretch processing producing marginally higher quality imagery by an average 0.46 dB in PSNR.