机载合成孔径雷达成像算法研究

The Study on Airborne SAR Imaging Algorithms

首先建立了机载合成孔径雷达回波信号的理论模型 ,阐述了SAR成像的基本原理 ,分析了目标与雷达之间的相对运动对成像的影响。然后对各种机载SAR成像处理算法进行了讨论和比较 ,包括标准的距离 -多普勒 (R -D)算法、改进的R -D算法、标准Chirp -Scaling(C -S)算法、扩展C -S算法和非线性C -S算法。分析表明 ,C -S算法以较小的运算量取得了较好的斜视情况下的性能 ,已取代R -D算法成为机载SAR成像的标准算法。最后指出了机载SAR成像算法今后的发展方向。

In this paper, the theoretical model of airborne SAR signal is constructed firstly. The principle of SAR imaging and the effects of relative motion between radar and target on imaging are analyzed. Then some airborne SAR imaging techniques are discussed and compared, including Range-Doppler (R-D) algorithm, improved R-D algorithm, Chirp-Scaling (C-S) algorithm, extended C-S algorithm and nonlinear C-S algorithm. The analyses show that C-S algorithm has the better performance in the squint mode with the lower computational cost, and it has been the standard airborne SAR imaging algorithm instead of the R-D algorithm. At last the frontier of airborne SAR imaging techniques is pointed out.