基于星载SAR信号的TEC反演新方法  

A new approach of TEC retrieval from the space-borne SAR

作　　者：王成[1] 张民[1] 许正文[2] 毛聪[3] 陈春[2] 

机构地区：[1]西安电子科技大学物理与光电工程学院,西安710071 [2]中国电波传播研究所,电波环境特性及模化技术重点实验室,青岛266107 [3]北京理工大学信息与电子学院,北京100081

出　　处：《地球物理学报》2014年第11期3570-3576,共7页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(61032009;61372004)资助

摘　　要：由于星载合成孔径雷达(SAR)系统工作于电离层之上,其信号不可避免地将受到电离层的影响.背景电离层以及电离层电子密度不规则体多重散射效应可引起距离向图像质量的下降,在强起伏情况下,多重散射效应对信号的延迟影响不可忽略.针对此问题,本文提出了一种基于SAR回波信号的三频相位自适应TEC反演新方法,利用反演的结果对电离层的影响进行校正.给出了校正前后的点目标成像仿真,结果显示此方法充分考虑了多重散射效应引起的TEC估计误差,可以有效地补偿电离层对距离向成像的影响,提高了距离向点目标图像质量.Due to the background ionosphere and irregularities in the electron density of the ionosphere, the space-borne synthetic aperture radar （SAR） imaging at low-frequency is affected by it inevitably. From the simulations, it can be seen that under the strong fluctuation regimes, the path delay of multiple scattering plays an important role in the total path delay of SAR signals. Aiming at this problem, a tri-band phase autofocus method of TEC retrieval based on the SAR echo is proposed, which compensates the effects of the ionosphere on SAR imaging. Simulation results show that when this method is used under strong fluctuations, both the image quality in range and the precision of SAR calibration are generally increased after compensation.

关 键 词：星载合成孔径雷达 电子密度不规则体 多重散射 三频相位自适应 

分 类 号：P352[天文地球—空间物理学] P237[天文地球—地球物理学]