地球同步轨道合成孔径雷达差分干涉处理理论与方法研究

项目名称： 地球同步轨道合成孔径雷达差分干涉处理理论与方法研究

项目编号： No.61471038

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 胡程

作者单位： 北京理工大学

项目金额： 80万元

中文摘要： 地球同步轨道合成孔径雷达差分干涉（GEO D-InSAR）利用地球同步轨道SAR卫星连续获取图像的相位差分信息来实现地表形变的反演。但是，相比于低轨D-InSAR，GEO D-InSAR合成孔径时间长（近千秒量级），弯曲轨迹效应明显；同时受电离层扰动影响大，信号存在欠相干效应；因此，高保相成像与欠相干约束下的高精度三维形变场反演是GEO D-InSAR亟待解决的核心科学问题。本项目将基于Appleton公式及多相屏理论实现GEO D-InSAR时空变电离层物理建模及定量影响分析；提出基于级数反转理论的两维非线性频率变标（NCS）与保相方法实现高保相成像；提出基于最大似然相关与KS (Kolmogorov-Smirnov)同类散射点检测实现欠相干区域的永久散射体增强；结合时空连续多角度观测与马尔可夫随机场模型实现高精度的三维形变场反演，为我国首颗GEO D-InSAR卫星的发射奠定理论基础。

中文关键词： 地球同步轨道合成孔径雷达；合成孔径雷达成像；电离层；差分干涉

英文摘要： Geosynchronous Synthetic Aperture Radar differential Interferometry (GEO D-InSAR) is able to obtain the surface deformation information by utilizing differential phase information of sequential time-series GEO SAR images. However, compared with low- orbit D-InSAR technnique, GEO D-InSAR has the extremely long synthetic apeture time (up to 1000-second order) and consequently the effect of trajectory curvature should be taken into account. Meanwhile, signal decorrelation is rather serious due to ionosphere interfering. Therefore, the investigations on image formation with high-quality phase perservation and 3-D deformation field retrieval under the constraint of deteriorated signal corherence are essential for GEO D-InSAR. There are 4 key issues involved in this project: 1) physical modeling with accomodation of temporal and spatial variance based on Appleton expression and multi-phase screen theory, and subsequently quantitative analysis of ionosphere effect; 2) higly accurate phase-preservation algorithm based on methods of series reversion and two-dimensional Nonlinear Chirp Scaling (NCS); 3) enhancement of permanent scatterers with deteriorated coherence through maximum likelihood correlation and Kolmogorov-Smirnov statistically homogeneous pixels detection; 4) retrieval of highly accurate three-dimensional deformation field by utilizing continuous temporal and spatial observations with multi-angle and Markov random field model. These works will lay the strong theorectical and technical foundation for the future launch of our first GEO D-InSAR satellite in China.

英文关键词： Geosynchronous SAR;SAR imaging;Ionosphere;D-InSAR