Influence of Frequency Source Stability on 2D Resolution of Spaceborne Synthetic Aperture Radar

Time counting of the spaceborne SAR payload system is realized by frequency division or frequency multiplication of the crystal oscillator source. For the monostatic SAR system, the same frequency source is used for both transceivers, and theoretically, there is no influence of frequency synchronization. However, for the actual crystal oscillator source, there is a certain frequency drift phenomenon in the sending and receiving time interval, so there will be errors during signal demodulation. In this paper, the sliding beamforming mode of monostatic spaceborne SAR radar is analyzed. First, the mathematical modeling of the echo signal of the monostatic SAR radar in this mode is carried out. Secondly, the phase error caused by the frequency drift of the frequency source is theoretically deduced. Finally, a simulation experiment is carried out to change the parameter values under different viewing angles and compare the resolution under different conditions and the output results of other parameters, so as to analyze the influence of the frequency source stability on the two-dimensional resolution of the spaceborne SAR radar.