{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,27]],"date-time":"2025-12-27T07:32:58Z","timestamp":1766820778897,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2024,4,29]],"date-time":"2024-04-29T00:00:00Z","timestamp":1714348800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42161067","202202AD080010","202401AU070173","2024J0067"],"award-info":[{"award-number":["42161067","202202AD080010","202401AU070173","2024J0067"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Major Scientific Technological Projects of Yunnan Province","award":["42161067","202202AD080010","202401AU070173","2024J0067"],"award-info":[{"award-number":["42161067","202202AD080010","202401AU070173","2024J0067"]}]},{"name":"Yunnan Fundamental Research Projects","award":["42161067","202202AD080010","202401AU070173","2024J0067"],"award-info":[{"award-number":["42161067","202202AD080010","202401AU070173","2024J0067"]}]},{"name":"Scientific Research Fund Project of Yunnan Provincial Department of Education","award":["42161067","202202AD080010","202401AU070173","2024J0067"],"award-info":[{"award-number":["42161067","202202AD080010","202401AU070173","2024J0067"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>SAR imagery plays a crucial role in geological and environmental monitoring, particularly in highland mountainous regions. However, inherent geometric distortions in SAR images often undermine the precision of remote sensing analyses. Accurately identifying and classifying these distortions is key to analyzing their origins and enhancing the quality and accuracy of monitoring efforts. While the layover and shadow map (LSM) approach is commonly utilized to identify distortions, it falls short in classifying subtle ones. This study introduces a novel LSM ground-range slope (LG) method, tailored for the refined identification of minor distortions to augment the LSM approach. We implemented the LG method on Sentinel-1 SAR imagery from the tri-junction area where the Xiaojiang, Pudu, and Jinsha rivers converge at the Yunnan-Sichuan border. By comparing effective monitoring-point densities, we evaluated and validated traditional methods\u2014LSM, R-Index, and P-NG\u2014against the LG method. The LG method demonstrates superior performance in discriminating subtle distortions within complex terrains through its secondary classification process, which allows for precise and comprehensive recognition of geometric distortions. Furthermore, our research examines the impact of varying slope parameters during the classification process on the accuracy of distortion identification. This study addresses significant gaps in recognizing geometric distortions and lays a foundation for more precise SAR imagery analysis in complex geographic settings.<\/jats:p>","DOI":"10.3390\/s24092834","type":"journal-article","created":{"date-parts":[[2024,4,29]],"date-time":"2024-04-29T10:33:36Z","timestamp":1714386816000},"page":"2834","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Accuracy Assessment of Geometric-Distortion Identification Methods for Sentinel-1 Synthetic Aperture Radar Imagery in Highland Mountainous Regions"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-8042-961X","authenticated-orcid":false,"given":"Chao","family":"Shi","sequence":"first","affiliation":[{"name":"Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China"}]},{"given":"Xiaoqing","family":"Zuo","sequence":"additional","affiliation":[{"name":"Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China"}]},{"given":"Jianming","family":"Zhang","sequence":"additional","affiliation":[{"name":"Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China"}]},{"given":"Daming","family":"Zhu","sequence":"additional","affiliation":[{"name":"Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China"}]},{"given":"Yongfa","family":"Li","sequence":"additional","affiliation":[{"name":"Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9412-3121","authenticated-orcid":false,"given":"Jinwei","family":"Bu","sequence":"additional","affiliation":[{"name":"Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"229482","DOI":"10.1016\/j.tecto.2022.229482","article-title":"The 23 February 2020 Qotur-Ravian earthquake doublet at the Iranian-Turkish border: Seismological and InSAR evidence for escape tectonics","volume":"838","author":"Taymaz","year":"2022","journal-title":"Tectonophysics"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"107577","DOI":"10.1016\/j.jvolgeores.2022.107577","article-title":"Unrest at Cayambe Volcano revealed by SAR imagery and seismic activity after the Pedernales subduction earthquake, Ecuador (2016)","volume":"428","author":"Audin","year":"2022","journal-title":"J. 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