圆周合成孔径雷达的快速时域成像算法

为实现圆周合成孔径雷达（Circular Synthetic Aperture Radar, CSAR）快速成像，提出一种用于CSAR的快速时域成像算法。该算法通过将CSAR的圆孔径分成若干子孔径，分别对子孔径采用快速因式分解后向投影算法处理，再将各子图像相干插值叠加至同一坐标系下得到成像结果。详细分析算法实现中的坐标转换、误差控制和运算效率等关键问题，并用点目标仿真和实测数据处理结果验证算法的有效性。所研究方法具有成像范围大、计算量小等优点。
In order to make the process of CSAR (circular synthetic aperture radar) imaging more efficient, a fast time-domain CSAR imaging method was presented. The proposed method was based on the circular aperture of the CSAR model, and the full aperture was divided into several sub-apertures; those sub-apertures were processed by the fast factorized back projection algorithm to get their corresponding sub-images; the final focused image was obtained by the coherent interpolation of the sub-images from the polar coordinate to the global coordinate system. Some key problems in the algorithm realization, such as coordinate transformation, error control and computation efficiency, were analyzed in detail. Experiments results based on the simulated data and real data were given to prove the validity of the proposed method. The proposed method has the advantages of improving imaging extension and lowering computational complexity.