频率源误差对地球同步轨道SAR成像性能影响分析

频率源相位误差作为合成孔径雷达(synthetic aperture radar, SAR)系统的一种时间去相干因素,对不同SAR系统的成像性能影响不同。对于低轨单基SAR系统,频率源相位误差通常可以忽略。而地球同步轨道(geosynchronous earth orbit, GEO)SAR系统具有更长的脉冲时延和合成孔径时间,此时频率源相位误差对成像性能的影响将不能被忽略。本文分析了频率源相位误差对GEO SAR系统成像性能的影响,并据此给出了GEO SAR系统对频率源相位特性的要求。

Impact of frequency oscillator errors on GEO SAR imaging performance

The oscillator phase error, as one of the decorrelation factors for the synthetic aperture radar (SAR) systems, has different impacts on different SAR systems. The impacts of oscillator phase errors are negligible for the low orbit monostatic SAR system. However, due to the long time delay of pulse return and long synthetic aperture time, the image quality of geosynchronous earth orbit (GEO) SAR suffers from the degradation caused by the oscillator phase error. The impacts of the oscillator phase error on the GEO SAR imaging performance are investigated. Furthermore, the constraints on the oscillator phase stability are given to guarantee the GEO SAR image quality.