由于机动平台成像的复杂性,常规SAR成像方法无法直接应用于俯冲模式下的大斜视成像处理。针对此问题,该文详细分析了俯冲段几何成像模型以及大斜视成像支撑区选择问题,提出一种基于坐标轴旋转的俯冲段大斜视SAR波数域成像算法。该算法根据部分孔径数据提出波数域聚焦处理,并通过坐标轴旋转实现频谱的高利用率,在有效避免了位置域聚焦的大量补零的前提下,保障了成像分辨率,提高了处理效率。仿真和实测数据处理验证了所提算法的有效性。
Due to the complexity of SAR imaging of maneuvering platform, traditional imaging algorithms are unavailable in the diving stage with high squint angle. To deal with these problems, the geometric model in diving stage of high squint SAR is constructed and discussed in detail. Furthermore, the spectrum support zone is analyzed. Then, a wavenumber-domain imaging algorithm for high squint diving SAR based on axes rotation is proposed. The wave-number domain imaging processing for sub-aperture data obtains high-usage of spectrum by axes rotation to guarantee the resolution. By doing so, zero-pudding operations in imaging domain are decreased effectively, which lead to the promotion of efficiency. Simulation results and real data processing are presented to valid the superiority of the proposed approach.