摘要：
The stability of side slope is very important to the construction and operation of high-speed railway. In this study, we proposed to jointly apply Interferometric synthetic aperture radar (InSAR) and BeiDou Navigation Satellite System (BDS) techniques to identify and monitor side slope along the Changgan high-speed railway. Deformation information along the Changgan high-speed railway was firstly derived by time-series InSAR (TSInSAR) using 68 Sentinel-1A SAR images spanning September 2019 to December 2021 for side slope identification, and then the identified unstable side slope (i.e., Xiahen side slope) was jointly monitored and analyzed by TSInSAR, BDS and unmanned aerial vehicle (UAV). The results show that: (1) TSInSAR can effectively identify unstable side slope, and monitoring results of side slope obtained by TSInSAR and BDS showed good agreement. (2) A large subsidence bowl was identified in the Xiahen side slope, and the maximum subsidence velocity reached − 57 mm/a. (3) Side slope stability was related to side slope treatment. The rainfall change was one of the important factors that affected the deformation of the Xiahen side-slope. The subsidence mainly happened in the rainy season, and a certain lag effect was observed in the subsidence change. (4) Geological structure had a certain influence on side slope deformation.
作者机构：
[Sheng, Haiquan; Zhou, Lv; Chen, Yukai; Xian, Lingxiao; Ma, Shubian] Guilin Univ Technol, Coll Geomatics & Geoinformat, Guilin 541004, Peoples R China.;[Huang, Changjun] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Yang, Fei] China Univ Min & Technol Beijing, Geosci & Survey Engn Coll, Beijing 100083, Peoples R China.
通讯机构：
[Lv Zhou] C;College of Geomatics and Geoinformation, Guilin University of Technology, Guilin 541004, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
InSAR;persistent scatterer;Beijing;plain;Sentinel-1A;time series
期刊：
Journal of the Indian Society of Remote Sensing,2023年51(10):2041-2056 ISSN：0255-660X
通讯作者：
Huang, CJ
作者机构：
[Xue, Yun; Huang, Changjun; Cao, Yuanzhi; Liu, Fenliang] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Huang, Changjun] Key Lab Key Technol Digital Urban Rural Spatial Pl, Yiyang 413000, Peoples R China.;[Zhou, Lv] Guilin Univ Technol, Sch Geomat & Geoinformat, Guilin 541004, Peoples R China.
通讯机构：
[Huang, CJ ] H;Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;Key Lab Key Technol Digital Urban Rural Spatial Pl, Yiyang 413000, Peoples R China.
作者机构：
[Xue, Yun; Huang, Changjun; Cao, Yuanzhi; Liu, Fenliang] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Zhou, Lv] Guilin Univ Technol, Sch Geomat & Geoinformat, Guilin 541004, Peoples R China.;[Liu, Zhong] Hunan Remote Sensing Geol Survey & Monitoring Inst, Changsha 411000, Peoples R China.
通讯机构：
[Changjun Huang] S;School of Municipal and Surveying Engineering, Hunan City University, Yiyang 413000, China<&wdkj&>Author to whom correspondence should be addressed.
作者机构：
[Xue, Yun; Xi, Zhen; Liu, Fenliang; Huang, Changjun] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.;[Gao, Hongshan] Lanzhou Univ, Coll Earth & Environm Sci, Key Lab Western Chinas Environm Syst, Minist Educ, Lanzhou 730000, Peoples R China.;[Li, Zongmeng] Xinyang Normal Univ, Sch Geog Sci, Xinyang 464000, Peoples R China.
通讯机构：
[Liu, FL ] H;Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang 413000, Peoples R China.
关键词：
lacustrine sediment;terrace;river evolution;Jinsha River
摘要：
<jats:p>The formation of the Jinsha River drainage is a significant subject of concern in the geological and geomorphological fields. Among them, one key question is whether there was a regional paleo lake into which Lower Jinsha River drainage drained during the late Pliocene to early Pleistocene, due to massive fluvio-lacustrine sediments widely distributed in the Lower Jinsha River. Nevertheless, there has yet to be a consensus on the genesis of those fluvio-lacustrine sediments due to poor sedimentological and chronological data. In this study, to unravel the origin of those fluvio-lacustrine sediments and the formation model of the Lower Jinsha River, sedimentary characteristics, including spatial distribution, lithological composition, and stratigraphic contact relationship of those fluvio-lacustrine sediments were analyzed, and chronological determination of the fluvio-lacustrine sediments using Electron Spin Resonance and Optically stimulated luminescence method was conducted. The results show that in the Lower Jinsha River, the lacustrine sediments are mainly composed of silt and clay, with apparent horizontal bedding, stacked with fluvial cobble-gravel and sand, and are in unconformable contact with the underlying bedrock strata or paleo soil. The lacustrine sediments are spatially discontinuous and mainly distributed in the Shigu, Taoyuan, Panzhihua, and Longjie reaches. Downstream of these reaches are deeply incised gorges with an average slope >30°, and many landslide landforms and deposits can be identified here. In each reach, the lacustrine sediments were closely distributed along the trunk and tributary channels in the plane and were distributed at different altitudes, forming a sequence of lacustrine terraces. Chronological analysis shows that in different reaches, the deposition ages of lacustrine sediments are significantly different. In each reach, the deposition age of the lacustrine terraces of high altitude is older than that of low altitude. The above characteristics collectively indicate that the lacustrine sediments in the Lower Jinsha River were locally deposited by individual dammed lakes, probably induced by landslide rather than a regional paleo lake by tectonic activities. During the incision process of the river valley, landslides continuously block the river channel, forming dammed lakes, and then deposited lacustrine sediments at different elevations, forming lacustrine terraces. The lacustrine sediment of the topmost lacustrine terrace in Panzhihua reach was dated to be 1.78 Ma, combined with previous studies on the fluvial terraces, indicating the Lower Jinsha River existed and started to incise its valley before the early Pleistocene. The widespread dammed lake sediment indicates that the formation of the Jinsha River valley follows the pattern of “incision-landslide-damming-aggradation-incision”.</jats:p>
作者机构：
[蒋瑜; 刘正才] College of Civil Engineering and Mechanics Xiangtan University, Xiangtan, 411105, China;[邬明权] State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100101, China;Institute of Municipal and Mapping Engineering Hunan City University, Yiyang, 413000, China;[黄长军] College of Civil Engineering and Mechanics Xiangtan University, Xiangtan, 411105, China<&wdkj&>Institute of Municipal and Mapping Engineering Hunan City University, Yiyang, 413000, China
作者机构：
[黄长军; 杨亚夫] School of Municipal and Surveying Engineering, Hunan City University, Yiyang;Hunan;413000, China;School of Geosciences and Info-Physics, Central South University, Changsha;410083, China
关键词：
遥感;合成孔径雷达;经验模态分解;永久散射体;噪声相位;概率统计
摘要：
基于经验模态分解(EMD),提出了一种改进的永久散射体(PS)探测方法。对干涉图进行多尺度分解,基于梯度的自适应滤波对分解的本征模函数中的噪声进行低信噪比区域强滤波和高信噪比区域弱滤波,估算滤波后各PS候选(PSC)点的噪声相位。基于各PSC点的幅度和相位稳定性,对选取的PSC点的相位信息进行分析,判断其作为PS点的概率,进而选取可靠的PS点。实验结果表明:与传统的PS点选取方法相比,所提方法避免了探测过程中PS点的误判和漏判,准确性更高。 In this study, an improved method based on empirical mode decomposition is proposed for the detection of persistent scatterers (PSs). The interferograms are decomposed from different angles, and noises contained in the decomposed intrinsic mode function (IMF) are strongly filtered in the low signal-to-noise ratio regions and weakly filtered in the high signal-to-noise ratio regions based on gradient adaptive filtering; the noise phase of each persistent scatterer candidate (PSC) point is estimated after filtering. Based on the stability of the amplitude and the phase of each PSC point, the phase information of the selected PSC point is analyzed to determine its probability of being a PS point, and the reliable PS points are selected. The experimental results denote that the proposed method avoids misjudgment and omission possibilities in the process of PS point detection with higher accuracy when compared to that exhibited by the traditional PS point detection method.
摘要：
In view of the low accuracy of traditional adjustment, an improved multiple-group adjustment method in indirect adjustment is proposed in this paper. In the process of improved multiple-group adjustment, the first group is first adjusted, and then the adjustment result of the first group and the observation value of the second group are adjusted together, which makes the results in the first-group adjustment meet the overall adjustment results. Finally, the posteriori unit-weight variance value, the coordinated factor matrix of the adjustment result, and the unknown function weight reciprocal are calculated. The experimental results show that the accuracy of multiple-group adjustment in the indirect grouping adjustment will be more accurate than the traditional indirect adjustment method. Moreover, this work provides important ideas and techniques for handling the goniometric triangular network of control surveys.
