Comparison of algorithms for squint side-looking strip imaging mode SAR

Squint side-looking strip imaging mode SAR has a variable squint angle from the side-looking direction, and has the capabilities of 'advance imaging' and 'turn-back imaging' to the terrain. The conventional side-looking mode SAR is only a special example of the squint mode SAR. Because of the large range migration and serious range-azimuth coupling terms, the imaging processing of squint mode SAR is a intrinsically 2D phenomenon. In this paper, different algorithms, which can be used for the imaging processing of squint mode SAR, are compared with each other in terms of their focusing quality and their ability to handle the large range migration and the space-variance of the correlation kernel of the squint side-looking mode SAR. And their ability of real-time imaging are also discussed. The algorithms contained here are 2D FFT method, fast polynomial transform method, and the direct correcting method based on range-Doppler focusing algorithms. Other new methods are also discussed here briefly.