机载斜视聚束合成孔径雷达快速成像算法

Fast imaging algorithm for airborne SAR with squinted spotlight mode

极坐标格式算法（PFA）是传统聚柬SAR的经典成像算法，但用于斜视聚束成像存在二维频域插值计算量巨大、插值精度受插值核函数长度制约以及最终图像旋转带来成像质量下降等问题。针对上述问题，文中提出一种基于尺度变化的快速PFA算法，不仅避免斜视成像后的图像旋转操作，还具有计算效率高的优势。快速PFA算法只需要FFT和复乘运算即可完成，与直接插值PFA算法相比计算量降低到原来的30％～50％。仿真实验验证了文中方法的有效性。

Polar format algorithm （PFA） is a classic imaging algorithm for spotlight SAR, but in squinted mode it brings some problems such as a great amount of 2D interpolation calculation and a limited interpolation accuracy restricted by the length of interpolation kernel as well as low imaging quality caused by image rotation. Aiming at the above problems, a novel fast PFA algorithm based on chirp scaling transformation is presented in this paper, which can avoid the image rotation operation after squinted imaging and also has the advantage of high computational efficiency. Fast PFA algorithm can just be realized by FFT and complex multiplication operation, so it can reduce the calculation to 30% 50% of the original. The simulation results verify the effectiveness of the proposed method.