时变大气层效应对地球同步轨道SAR成像影响的分析与补偿

发布时间：2018-04-06 02:16

本文选题：地球同步轨道SAR　切入点：大气层　出处：《信号处理》2017年10期

【摘要】：大气层效应会导致穿过其中的星载合成孔径雷达(SAR)信号产生相位误差,并进而可能造成星载SAR成像结果出现散焦现象。大气层效应包括背景电离层效应、电离层多重散射效应以及对流层效应,由于地球同步轨道SAR(GEO SAR)合成孔径时间可达几百秒量级,因此在其成像积累时间内大气层效应会随时间变化,因此必须考虑时变大气层效应对GEO SAR成像的影响,同时亟需研究时变大气层效应对GEO SAR成像影响的补偿方法。本文详细分析了时变大气层效应对SAR信号的影响机理,建立了时变大气层效应影响下的高精度GEO SAR回波信号模型,分析了时变大气层效应对GEO SAR成像的影响,并基于方位向子孔径划分,通过提取时变大气层相位误差,对大气层效应造成的GEO SAR图像散焦现象进行了补偿。
[Abstract]:The atmospheric effect will lead to phase error of spaceborne synthetic aperture radar (SAR) signal passing through it, which may lead to defocusing of spaceborne SAR imaging results.The atmospheric effects include the background ionospheric effect, the ionospheric multiple scattering effect and the tropospheric effect, due to the geosynchronous orbit (SAR(GEO SAR) synthetic aperture time of several hundred seconds.Therefore, the effect of time-varying atmosphere on GEO SAR imaging must be considered, and it is urgent to study the compensation method of time-varying atmospheric effect on GEO SAR imaging.In this paper, the influence mechanism of time-varying atmosphere effect on SAR signal is analyzed in detail, and the high-precision GEO SAR echo signal model under the influence of time-varying atmosphere effect is established. The influence of time-varying atmosphere effect on GEO SAR imaging is analyzed.Based on the azimuth subaperture partition, the defocusing phenomenon of GEO SAR image caused by atmospheric effect is compensated by extracting the phase error of time-varying atmosphere.
【作者单位】：中国电子科学研究院;北京理工大学信息与电子学院;卫星导航电子信息技术教育部重点实验室(北京理工大学);
【基金】：国家自然科学基金资助(61225005,61471038,61501032,61427802,61120106004) 北京市自然科学基金资助(4162052) 中国高校“111计划”(B14010)
【分类号】：TN958;V443.2

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