摘要
川藏铁路作为中国意义非凡的重大工程,也是世界铁路史上地形最复杂、地质安全问题最严峻的铁路。合成孔径雷达干涉测量技术(interferometric synthetic aperture radar,InSAR)凭借其广覆盖、高精度、高效率等特点已成为地质灾害隐患早期识别与监测的重要手段,但是其在川藏线地形起伏剧烈的高山峡谷区域会面临较为严重的几何畸变问题。以覆盖面最广、获取时间最密的全球完全开放获取的哨兵1号卫星(Sentinel-1)数据为例,将川藏铁路沿线作为研究区域开展卫星雷达影像几何畸变与适宜性分析。综合考虑合成孔径雷达(synthetic aperture radar,SAR)成像几何、Sentinel-1影像斜距向入射角差异及被动几何畸变3个方面,提出了一套基于局部入射角的Sentinel-1影像几何畸变区域精准定量识别方法,并对川藏线全线几何畸变进行了定量计算与升降轨适宜性分析。结果显示:川藏线所在极陡高山峡谷区单轨道几何畸变区域达到31%~35%,升降轨联合观测可以有效将几何畸变区域减小至1.5%,同时约有35%区域适宜升降轨同时观测进行联合分析。
Objectives:The Sichuan-Tibet railway is not only a state key project in China,but also the most difficult super project in railway construction history due to the most complex terrain and the active geological structure.Interferometric synthetic aperture radar(InSAR) has proved to be a critical tool for detecting and monitoring geohazards because of its wide coverage,high precision,and high efficiency.However,due to its side-looking geometry,InSAR faces serious geometric distortions in mountainous areas,particularly in extremely steep high mountain and gorge areas along the Sichuan-Tibet railway.Methods:Utilizing the full open-access Sentinel-1 data,which has the wide coverage and a short revisiting time,we carry out satellite radar geometric distortion and feasibility analyses along the Sichuan-Tibet railway.Taking into account synthetic aperture radar(SAR) imaging geometry,the variations of the incidence angles across the whole SAR image,and the passive geometric distortions,we present an integrated approach to accurately determine the areas with SAR geometric distortions.Results:Our results for Sentinel-1 data show that the areas with geometric distortions for observations with a single-orbit(i.e.ascending or descending)reach 31%—35% along the Sichuan-Tibet railway,whilst the geometric distortion areas reduce to 1.5%for observations with both ascending and descending orbits;furthermore,about 35% of the whole area is suitable for joint analyses with both ascending and descending observations.Conclusions:The quantitative result also reveals the feasibility to use the Sentinel-1 data to detect and monitor geohazards along the Sichuan-Tibet railway from the perspective of geometric distortions.It can not only improve the overall understanding of the applicability of Sentinel-1 based InSAR and the InSAR results interpretation in this area,but also provide a guideline for efficiently selecting other satellite SAR datasets for detecting and monitoring geological disasters along the Sichuan-Tibet railway.
作者
戴可人
张乐乐
宋闯
李振洪
卓冠晨
许强
DAI Keren;ZHANG Lele;SONG Chuang;LI Zhenhong;ZHUO Guanchen;XU Qiang(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China;College of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China;Key Laboratory of Western China's Mineral Resources and Geological Engineering,Ministry of Education,Xi'an 710054,China;School of Engineering,Newcastle University,Newcastle NE17RU,England;Geosciences and Satellite Big Data Research Center of Chang'an University,Xi'an 710054,China)
出处
《武汉大学学报（信息科学版）》
EI
CAS
CSCD
北大核心
2021年第10期1450-1460,共11页
Geomatics and Information Science of Wuhan University
基金
国家自然科学基金(41941019,41801391)
地质灾害防治与地质环境保护国家重点实验室自主研究课题(SKLGP2020Z012)。
作者简介
第一作者:戴可人,博士,教授,主要从事基于InSAR与多光谱遥感技术的地质灾害早期识别,监测预警与风险防控研究。daikeren17@cdut.edu.cn;通讯作者:李振洪,博士,教授。zhenhong.li@chd.edu.cn。
