{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T19:22:32Z","timestamp":1778181752724,"version":"3.51.4"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,4,21]],"date-time":"2022-04-21T00:00:00Z","timestamp":1650499200000},"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":["42171355"],"award-info":[{"award-number":["42171355"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42071410"],"award-info":[{"award-number":["42071410"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41871069"],"award-info":[{"award-number":["41871069"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Sichuan Science and Technology Program","award":["2021JDJQ0009"],"award-info":[{"award-number":["2021JDJQ0009"]}]},{"name":"Sichuan Science and Technology Program","award":["2020YJ0322"],"award-info":[{"award-number":["2020YJ0322"]}]},{"name":"Sichuan Science and Technology Program","award":["2020JDTD0003"],"award-info":[{"award-number":["2020JDTD0003"]}]},{"name":"Sichuan Science and Technology Program","award":["2019ZDZX0042"],"award-info":[{"award-number":["2019ZDZX0042"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Mapping the outlines of glaciers has primarily relied on the interpretation of satellite optical images. However, the accurate delineation of glaciers in complex terrain mountain regions remains challenging, mainly because the supraglacial debris-covered ablation zones and snow-covered accumulation zones often exhibit the same spectral properties as their adjacent grounds in optical images. This study presents a novel approach by exploring both the satellite synthetic aperture radar (SAR) amplitude and interferometric coherence to map mountain glaciers. This method explores the deviation of the glacier surface signal in the SAR time series to distinguish glacier ice from the surrounding stable ground. To this end, we explored the classifying capabilities of two indices from a set of SAR images, SAR interferometric coherence and amplitude deviation index (ADI), to determine glacier boundary. We found that the two indices complement each other for mapping glaciers. A ratio map based on ADI and SAR coherence (ACR) was then derived, from which the glacier outline was automatically tracked using a specified threshold, followed by manual modification. We validated this approach on two typical valley glaciers, the debris-covered Hailuogou Glacier and debris-free Mozigou Glacier, in Mount Gongga in the southeastern Tibetan Plateau. The results show that the proposed ACR criteria can significantly enhance the contrast between glaciers and their surroundings. By comparing our results with manually delineated glacier outlines from high-resolution cloud-free satellite optical imagery, we found that the misclassification rate and difference rate for our results were 2.6% and 4.2%, respectively. The approach presented in this study can be easily adapted to map the outlines of mountain glaciers worldwide efficiently and is useful for inferring glacier boundary changes in a climate warming context.<\/jats:p>","DOI":"10.3390\/rs14091993","type":"journal-article","created":{"date-parts":[[2022,4,24]],"date-time":"2022-04-24T00:45:21Z","timestamp":1650761121000},"page":"1993","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Semi-Automated Mapping of Complex-Terrain Mountain Glaciers by Integrating L-Band SAR Amplitude and Interferometric Coherence"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7056-1124","authenticated-orcid":false,"given":"Bo","family":"Zhang","sequence":"first","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guoxiang","family":"Liu","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"},{"name":"State-Province Joint Engineering Laboratory of Spatial Information Technology of High-Speed Rail Safety, Chengdu 611756, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6532-9606","authenticated-orcid":false,"given":"Xiaowen","family":"Wang","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"},{"name":"State-Province Joint Engineering Laboratory of Spatial Information Technology of High-Speed Rail Safety, Chengdu 611756, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yin","family":"Fu","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7285-5425","authenticated-orcid":false,"given":"Qiao","family":"Liu","sequence":"additional","affiliation":[{"name":"Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bing","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu 610500, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0809-7682","authenticated-orcid":false,"given":"Rui","family":"Zhang","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"},{"name":"State-Province Joint Engineering Laboratory of Spatial Information Technology of High-Speed Rail Safety, Chengdu 611756, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhilin","family":"Li","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"},{"name":"State-Province Joint Engineering Laboratory of Spatial Information Technology of High-Speed Rail Safety, Chengdu 611756, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.cageo.2006.05.015","article-title":"Remote sensing and GIS technology in the Global Land Ice Measurements from Space (GLIMS) Project","volume":"33","author":"Raup","year":"2007","journal-title":"Comput. Geosci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1080\/10106040408542307","article-title":"Global Land Ice Measurements from Space (GLIMS): Remote Sensing and GIS Investigations of the Earth\u2019s Cryosphere","volume":"19","author":"Bishop","year":"2004","journal-title":"Geocarto Int."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"537","DOI":"10.3189\/2014JoG13J176","article-title":"The Randolph Glacier Inventory: A globally complete inventory of glaciers","volume":"60","author":"Pfeffer","year":"2014","journal-title":"J. Glaciol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"357","DOI":"10.3189\/2015JoG14J209","article-title":"The second Chinese glacier inventory: Data, methods and results","volume":"61","author":"Guo","year":"2015","journal-title":"J. Glaciol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"849","DOI":"10.5194\/tc-9-849-2015","article-title":"The GAMDAM glacier inventory: A quality-controlled inventory of Asian glaciers","volume":"9","author":"Nuimura","year":"2015","journal-title":"Cryosphere"},{"key":"ref_6","unstructured":"Sakai, A. (2015). GAMDAM glacier inventory for High Mountain Asia. PANGAEA."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1657\/AAAR0013-104","article-title":"Glacier Changes in the Lancang River Basin, China, between 1968\u20131975 and 2005\u20132010","volume":"47","author":"Liu","year":"2015","journal-title":"Arctic Antarct. Alp. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"103","DOI":"10.5194\/tc-12-103-2018","article-title":"Recent glacier mass balance and area changes in the Kangri Karpo Mountains from DEMs and glacier inventories","volume":"12","author":"Wu","year":"2018","journal-title":"Cryosphere"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"116450","DOI":"10.1016\/j.epsl.2020.116450","article-title":"Interannual flow dynamics driven by frontal retreat of a lake-terminating glacier in the Chinese Central Himalaya","volume":"546","author":"Liu","year":"2020","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/j.rse.2005.07.004","article-title":"Multispectral imaging contributions to global land ice measurements from space","volume":"99","author":"Kargel","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"444","DOI":"10.3189\/002214309788816632","article-title":"Estimation of debris cover and its temporal variation using optical satellite sensor data: A case study in Chenab basin, Himalaya","volume":"55","author":"Shukla","year":"2009","journal-title":"J. Glaciol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.rse.2009.08.015","article-title":"Landsat-based inventory of glaciers in western Canada, 1985\u20132005","volume":"114","author":"Bolch","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1016\/j.rse.2013.07.043","article-title":"The glaciers climate change initiative: Methods for creating glacier area, elevation change and velocity products","volume":"162","author":"Paul","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"6607","DOI":"10.1080\/01431161.2019.1582114","article-title":"Development of glacier mapping in Indian Himalaya: A review of approaches","volume":"40","author":"Kaushik","year":"2019","journal-title":"Int. J. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3078","DOI":"10.3390\/rs4103078","article-title":"Decision Tree and Texture Analysis for Mapping Debris-Covered Glaciers in the Kangchenjunga Area, Eastern Himalaya","volume":"4","author":"Racoviteanu","year":"2012","journal-title":"Remote Sens."},{"key":"ref_16","unstructured":"Raup, B., and Khalsa, S.J.S. (2010). GLIMS Analysis Tutorial, National Snow. Available online: http:\/\/www.glims.net\/MapsAndDocs\/assets\/GLIMS_Analysis_Tutorial_a4.pdf."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1525","DOI":"10.1126\/science.262.5139.1525","article-title":"Satellite Radar Interferometry for Monitoring Ice Sheet Motion: Application to an Antarctic Ice Stream","volume":"262","author":"Goldstein","year":"1993","journal-title":"Science"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2384","DOI":"10.1109\/TGRS.2002.805079","article-title":"Glacier motion estimation using SAR offset-tracking procedures","volume":"40","author":"Strozzi","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"867","DOI":"10.5194\/tc-12-867-2018","article-title":"Using SAR satellite data time series for regional glacier mapping","volume":"12","author":"Winsvold","year":"2018","journal-title":"Cryosphere"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"102948","DOI":"10.1016\/j.earscirev.2019.102948","article-title":"Remote sensing of glacier and ice sheet grounding lines: A review","volume":"201","author":"Friedl","year":"2020","journal-title":"Earth-Sci. Rev."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"S186","DOI":"10.5589\/m10-014","article-title":"Using L-band SAR coherence to delineate glacier extent","volume":"36","author":"Atwood","year":"2010","journal-title":"Can. J. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"832","DOI":"10.1016\/j.rse.2012.06.020","article-title":"Compilation of a glacier inventory for the western Himalayas from satellite data: Methods, challenges, and results","volume":"124","author":"Frey","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"372","DOI":"10.1016\/j.rse.2015.10.001","article-title":"Automated classification of debris-covered glaciers combining optical, SAR and topographic data in an object-based environment","volume":"170","author":"Robson","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"811","DOI":"10.1017\/jog.2018.70","article-title":"Automatic delineation of debris-covered glaciers using InSAR coherence derived from X-, C- and L-band radar data: A case study of Yazgyl Glacier","volume":"64","author":"Lippl","year":"2018","journal-title":"J. Glaciol."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Shi, Y., Liu, G., Wang, X., Liu, Q., Zhang, R., and Jia, H. (2019). Assessing the Glacier Boundaries in the Qinghai-Tibetan Plateau of China by Multi-Temporal Coherence Estimation with Sentinel-1A InSAR. Remote Sens., 11.","DOI":"10.3390\/rs11040392"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Zakhvatkina, N., Smirnov, V., and Bychkova, I. (2019). Satellite SAR Data-based Sea Ice Classification: An Overview. Geosciences, 9.","DOI":"10.3390\/geosciences9040152"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1109\/36.898661","article-title":"Permanent scatterers in SAR interferometry","volume":"39","author":"Ferretti","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2942","DOI":"10.1109\/TGRS.2010.2043442","article-title":"Decorrelation of L-Band and C-Band Interferometry Over Vegetated Areas in California","volume":"48","author":"Wei","year":"2010","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"215","DOI":"10.3189\/002214310791968520","article-title":"Recent shrinkage and hydrological response of Hailuogou glacier, a monsoon temperate glacier on the east slope of Mount Gongga, China","volume":"56","author":"Liu","year":"2010","journal-title":"J. Glaciol."},{"key":"ref_30","first-page":"112","article-title":"Persistent scatterer interferometric synthetic aperture radar for crustal deformation analysis, with application to Volc\u00e1n Alcedo, Gal\u00e1pagos","volume":"112","author":"Hooper","year":"2007","journal-title":"J. Geophys. Res. Earth Solid Earth"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1109\/36.739146","article-title":"Coherence estimation for SAR imagery","volume":"37","author":"Touzi","year":"1999","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_32","unstructured":"Werner, C., Wegm\u00fcller, U., Strozzi, T., and Wiesmann, A. (2000, January 16\u201320). Gamma SAR and interferometric processing software. Proceedings of the Ers-Envisat Symposium, Gothenburg, Sweden."},{"key":"ref_33","unstructured":"Ferretti, A., Monti-Guarnieri, A., Prati, C., Rocca, F., and Massonnet, D. (2007). InSAR Principles: Guidelines for SAR Interferometry Processing and Interpretation, European Space Agency (ESA) Publications."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1080\/2151237X.2007.10129236","article-title":"Adaptive Thresholding using the Integral Image","volume":"12","author":"Bradley","year":"2007","journal-title":"J. Graph. Tools"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1109\/TSMC.1979.4310076","article-title":"A threshold selection method from gray-level histograms","volume":"9","author":"Otsu","year":"1979","journal-title":"IEEE Trans. Syst. Man Cybern."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1035","DOI":"10.3189\/2013JoG12J184","article-title":"The influence of debris cover and glacial lakes on the recession of glaciers in Sikkim Himalaya, India","volume":"59","author":"Basnett","year":"2013","journal-title":"J. Glaciol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2063","DOI":"10.1080\/2150704X.2015.1034886","article-title":"A new band ratio technique for mapping debris-covered glaciers using Landsat imagery and a digital elevation model","volume":"36","author":"Alifu","year":"2015","journal-title":"Int. J. Remote Sens."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3501","DOI":"10.1029\/2000GL012484","article-title":"Penetration depth of interferometric synthetic-aperture radar signals in snow and ice","volume":"28","author":"Rignot","year":"2001","journal-title":"Geophys. Res. Lett."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"668","DOI":"10.1038\/ngeo2999","article-title":"A spatially resolved estimate of High Mountain Asia glacier mass balances from 2000 to 2016","volume":"10","author":"Brun","year":"2017","journal-title":"Nat. Geosci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1038\/s41561-018-0271-9","article-title":"Twenty-first century glacier slowdown driven by mass loss in High Mountain Asia","volume":"12","author":"Dehecq","year":"2019","journal-title":"Nat. Geosci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/9\/1993\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:58:09Z","timestamp":1760137089000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/9\/1993"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,4,21]]},"references-count":40,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2022,5]]}},"alternative-id":["rs14091993"],"URL":"https:\/\/doi.org\/10.3390\/rs14091993","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,4,21]]}}}