条带式合成孔径雷达成像方法研究

Study of the stripmap synthetic aperture radar imaging method

提出准正侧视合成孔径雷达小斜视角度的校正方法和子孔径参考信号相位对齐算法.准正侧视合成孔径雷达(SAR)成像的校正方法采用正侧视的子孔径聚束算法对准正侧视SAR的实测数据进行成像,根据所成的像估计出小角度斜视角,采用校正的斜视子孔径聚束算法完成最后的成像.子孔径参考信号相位对齐算法本质是将各个子孔径参考信号的相位调整为同相,并构造新的聚束窗函数进行SAR成像.理论分析指出,在不增加采样数据的条件下,该方法能增大雷达方位向成像场景范围.计算机仿真结果证实了所提方法的正确性.

The paper deals with a calibration method for quasi-broadsie side-looking mode SAR imaging with a small squint angle. First, the method adopts the broadside side-looking mode subaperture spotlighting algorithm to image the real data of the quasi-broadside side-looking mode SAR, and then based on the obtained image the small squint angle is estimated. Finally, the calibrated squint side-looking mode subaperture spotlighting algorithm is employed to obtain the final image. The paper also places emphasis on a novel method called the phase alignment algorithm for subaperture reference signals. The algorithm adjusts phases of respective subaperture reference signals in order to make them in phase and constructs a new spotlighting window function for SAR imaging. The theoretical analysis shows that under the condition of the same sample data, the novel method can increase the SAR scene area in azimuth dimension. The methods are verified by the results of computer simulation.