电离层闪烁对GEO SAR成像的影响分析

Analysis of the Ionospheric Scintillation Effects on GEO SAR Imaging

研究电离层闪烁效应对GEO SAR成像的影响.针对GEO SAR系统的特点,首先通过GEO SAR系统参数的仿真,分析电离层对于GEO SAR影响的特殊性,而后通过多相屏理论,仿真分析电离层闪烁产生的随机起伏现象对GEO SAR系统图像质量的影响,最后结合Monte Carlo仿真,给出了不同电离层起伏条件下GEO SAR直接合成孔径处理的最优积累时间.分析结果表明:相同GEO SAR系统参数下,电离层闪烁起伏越大,合成时间越长,成像质量结果越差,甚至会出现无法聚焦的情况.

The ionospheric scintillation effects on GEO SAR imaging was analyzed.Firstly,according to the characteristics of the GEO SAR system,corresponding simulations were carried out to illustrate the particular effects of the ionosphere on the GEO SAR.Then,based on the multiple phase screen theory,the effect of random phase fluctuation phenomena caused by the ionosphere scintillation was simulated and analyzed on the quality of GEO SAR imaging.At last,the optimal accumulation time of the GEO SAR processing was presented under the condition of the ionospheric scintillation through Monte Carlo methods.Simulation results show that GEO SAR imaging become deteriorated and even defocused when the scintillation is severe and the synthetic aperture time is much longer.