基于DFT滤波器组的大斜视SAR成像算法

Highly Squint SAR Imaging Algorithm Based on DFT Filter Banks

传统的大斜视角SAR成像算法利用时域线性走动减少距离徙动校正的难度,运用非线性变标算法改善方位向的聚焦效果,然而变标因子的引入也带来了一些处理上的不便。针对这一问题,该文从分块近似匹配的角度出发,结合DFT滤波器组理论,提出了一种方位向聚焦的新算法。与传统的方位非线性变标类算法相比,新算法不引入相位操作,能更好地补偿空变的多普勒调频率,稳定性和成像性能都得到了提高,且在一般情况下算法的计算量要少于传统算法。仿真结果证明了算法的有效性。

The traditional highly squint SAR imaging algorithm reduces the difficulty in range migration correction by using the time-domain linear walking, and improves the azimuth focusing effect by applying non-linear scaling algorithm. However, the variable standard factor introduced also causes some difficulty for processing. To tackle this problem, this article proposes a new algorithm of azimuth focusing on basis of DFT filter bank theory. Compared with the traditional non-linear scaling algorithm, the new algorithm can compensate Doppler frequency rate better by no introduction of phase operation. The stability is improved and the calculation needed is also less than the traditional algorithm. The simulation results presented proves the effectiveness of the proposed algorithm.