高效星载TOPSAR场景回波信号模拟方法

Efficient Spaceborne TOPS Mode SAR Raw Signal Simulation of Extended Scenes

星载TOPSAR回波信号模拟中时域逐点法运算效率低,而2维频域法又无法直接模拟星载TOPSAR回波信号。针对这个问题,该文提出了一种高效的星载TOPSAR模式场景回波模拟方法。该方法在距离向上利用参考点回波与场景散射矩阵卷积完成,在方位向上采用对逐个慢时间进行模拟和存储。文中详细给出该方法的处理流程,分析了该方法的运算量,同时还对比了点目标模拟结果与精确的时域模拟方法的差异,最后利用模拟回波信号的成像及干涉结果验证了该文方法的有效性。

The SAR raw signal simulator in the time domain by the target-by-target method is inefficient,while the simulator in the two-dimensional（2-D） frequency domain can not be directly used to generate the Terrain Observation by Progressive Scans（TOPS） raw data.As for this issue,an efficient TOPS raw data simulation approach is proposed.In the range direction,the 1-D convolution between echoes of referenced point target and scattering coefficient of the imaged scene is introduced,while raw data is simulated and stored by the pulse-by-pulse method in azimuth.The processing steps of the simulator are given in detail,and its computational complexity is analyzed.Simulated echoes of the proposed simulator and the accurate time domain simulator are compared.Finally,the imaging and interferometry results of the simulated data are given to validate the effectiveness of the proposed approach.