回波仿真是进行合成孔径雷达(synthetic aperture radar,SAR)研究的重要途径,但其计算量巨大,所需的时间较长。为了快速实现SAR回波仿真,提出一种改进的同心圆方法进行快速计算,同时考虑到运算较为规整的特点,采用现场可编程门阵列(field programmable gate array,FPGA)作为主处理芯片。设计了专用于SAR回波信号模拟的数字信号处理板卡,并在板卡上编程实现整个回波模拟算法,给出资源使用情况和量化噪声影响,实际应用结果显示,采用FPGA来实现SAR回波仿真可以在保证精度的前提下大大加快仿真速度。
Echo simulation is of great significance to the research on synthetic aperture radar(SAR),but massive computation and longer time are needed.In order to realize SAR echo simulation fast,an improved concentric circles method is adopted to obtain a fast computation.Considering that the computation has the characteristics of regulation,the field programmable gate array(FPGA) is adopted as the kernel chirp to design the digital signal processing board to be specially used in SAR echo simulation.The simulation algorithm is realized on the board by programming,and then the resource usage and the quantization noise are given.The application result shows that the realization of SAR echo simulation based on FPGA can greatly accelerate the simulation speed and significantly reduce energy consumption.