{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T15:33:42Z","timestamp":1760369622578,"version":"build-2065373602"},"reference-count":40,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,6,8]],"date-time":"2020-06-08T00:00:00Z","timestamp":1591574400000},"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":["41901304","41971318"],"award-info":[{"award-number":["41901304","41971318"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Water clarity, commonly measured as the Secchi disk depth (    Z  s d     ), is an important parameter that depicts water quality in aquatic ecosystems. China\u2019s new generation Advanced HyperSpectral Imager (AHSI) on board the GF-5 satellite has significant potential for applications of more accurate water clarity estimation compared with existing multispectral satellite imagery, considering its high spectral resolution with a 30-m spatial resolution. In this study, we validate the semi-analytical model with various Quasi-Analytical Algorithms (QAA), including     Q A  A  V 5      ,     Q A  A  V 6      ,     Q A  A  L 09       and     Q A  A  M 14      , for the AHSI images with concurrent in situ measurements in four inland water bodies with a     Z  s d      range of 0.3\u20134.5 m. The semi-analytical method with     Q A  A  V 5       can yield the most accurate     Z  s d      predictions with approximated atmospheric-corrected remote sensing reflectance. For 84 concurrent sampling sites, the estimated     Z  s d      had a mean absolute error (MAE) of 0.35 m, while the mean relative error (MRE) was 25.3%. Specifically, the MAEs of estimated     Z  s d      were 0.22, 0.46, and 0.24 m for     Z  s d      of 0.3\u20131, 1\u20133, and 3\u20134.5 m, respectively. The corresponding MREs were 33.1%, 29.1% and 6.3%, respectively. Although further validation is still required, especially in terms of highly turbid waters, this study indicates that AHSI is effective for water clarity monitoring.<\/jats:p>","DOI":"10.3390\/rs12111849","type":"journal-article","created":{"date-parts":[[2020,6,9]],"date-time":"2020-06-09T05:16:14Z","timestamp":1591679774000},"page":"1849","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["Secchi Disk Depth Estimation from China\u2019s New Generation of GF-5 Hyperspectral Observations Using a Semi-Analytical Scheme"],"prefix":"10.3390","volume":"12","author":[{"given":"Yao","family":"Liu","sequence":"first","affiliation":[{"name":"Land Satellite Remote Sensing Application Center, Ministry of Natural Resources of China, Beijing 100048, China"}]},{"given":"Chenchao","family":"Xiao","sequence":"additional","affiliation":[{"name":"Land Satellite Remote Sensing Application Center, Ministry of Natural Resources of China, Beijing 100048, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8590-9736","authenticated-orcid":false,"given":"Junsheng","family":"Li","sequence":"additional","affiliation":[{"name":"Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9628-1817","authenticated-orcid":false,"given":"Fangfang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China"}]},{"given":"Shenglei","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"Institute of Remote Sensing and Geographic Information System, Peking University, Beijing 100871, China"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1007\/s00267-010-9440-3","article-title":"Eutrophication of lake waters in China: Cost, causes, and control","volume":"45","author":"Le","year":"2010","journal-title":"Environ. 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