A Spaceborne SAR Simulator
星载合成孔径雷达回波信号模拟源研究

This paper introduces a real-time spaceborne SAR simulator and the hardware design based onthe PCI bus and CPLD chip. This simulator is mainly based on the parameters of the SAR and the satelliteorbit. The foundations of the simulation method are the point target model, the ellipse orbit model, andthe ellipse earth model. First, the simulation software can calculate both the phase-shifted data and theweighted data of the azimuth direction of antenna. These data can be synthesized and stored in one file.Second, these data are transferred to the time-controlled unit through PCI bus. Then, the LFM generatesthe linear frequency modulated signal, which is phase-shifted and weighted in the simulator, by means ofthe delay signal generated by CPLD timer. Finally, the system echo signal is formed. This signal can beused to verify the system characteristics, such as resolution, bandwidth, and the spectrum features etc..After digitalization, the data are stored in the storage device in the PC. Based on the classical R-Dalgorithm, the compressed data can be achieved. The compression results in this paper show that thismethod is feasible, and that the flexibility of the software and the hardware of the simulator hasadvantages in the system update and the distributed target simulator design.