A new method for ground moving target imaging with single-antenna SAR

When the synthetic aperture radar (SAR) imaging is applied to observe a ground scene containing a ground moving target, the moving target image will be typically smeared due to the range cell migration and Doppler spectrum broadening caused by target motions. To eliminate these motion effects, a novel algorithm for ground moving target imaging, which is based on an improved axis rotation-time reversal transform (IAR-TRT), is proposed in this paper. In this method, the linear range migration is corrected by an improved axis rotation (IAR) operation and then the coherent integration is accomplished by a time reversal transform (TRT). The proposed method has low computational complexity since the exhaustive searching for the Doppler chirp rate estimation is avoided, which is suitable for real-time imaging. In addition, the defocusing influence of Doppler ambiguity can be eliminated. The effectiveness of the proposed algorithm is demonstrated by the simulation results in a single-channel airborne SAR system.