基于北斗反射波的干涉SAR及形变监测研究

地表形变对人类生存环境和正常经济生活造成了严重的威胁，需要进行长期连续的地表形变监测。原位站点测量方法精度高但观测点稀疏、甚至因为形变体危险导致无法布设。普通SAR卫星遥感观测受到卫星数量少和重返周期长等限制导致观测不连续。本项目提出利用北斗卫星和地基/机载接收机组成基于北斗反射电波的双基地干涉SAR(BDS-InSAR)，用于形变监测。研究内容包括：（1）建立利用重复轨道的北斗卫星配合地面反射接收机构成重轨干涉模型和利用地面双天线接收的单轨干涉模型，研究干涉图的生成算法；（2）研究BDS-InSAR干涉图应用于地表形变监测的流程和算法，包括永久散射体提取、相位解缠等；（3）研究BDS-InSAR中的各类误差因素，研究减弱/消除误差的算法。.项目研究成果将拓展北斗导航系统的新应用，并为星载BDS-InSAR的地形监测打下基础。

Since surface deformation poses a serious threat to human living environment and normal economic life, Long-term continuous monitoring of surface deformation is required. The in-situ site equipment has high accuracy but the observation points are sparse, and even the device cannot be deployed due to the danger of deformation bodies. The remote sensing observation of SAR satellite is limited by the number of satellites and the long return period, which leads to the discontinuity of observation. . In this project, a bistatic interferometric SAR (BDS-InSAR) based on Beidou reflected radio waves is proposed for deformation, which is composed of Beidou satellite and ground / airborne receiver. The main research contents include: (1) establish the repeat-pass differential interferometric model composed of the Beidou satellite with the ground reflection receiver and the single orbit interference model received by the ground dual antenna, and give the generation algorithm of the interferogram; (2) explore the processing flow and algorithm of BDS-InSAR interferogram applied to the surface deformation monitoring , including the extraction of permanent scatterers and the phase unwrapping; (3) study various error factors in BDS-InSAR, and study the algorithm of reducing / eliminating errors. .The research results of the project will expand the new application of Beidou navigation system and lay a foundation for the terrain monitoring of BDS-InSAR on board.