{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T10:38:40Z","timestamp":1784716720774,"version":"3.55.0"},"reference-count":37,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,13]],"date-time":"2021-11-13T00:00:00Z","timestamp":1636761600000},"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":["41604003, 41704017, 41704018, 41874032 and 41931076"],"award-info":[{"award-number":["41604003, 41704017, 41704018, 41874032 and 41931076"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2020YFB0505800"],"award-info":[{"award-number":["2020YFB0505800"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Flood is a kind of natural disaster that is extremely harmful and occurs frequently. To reduce losses caused by the hazards, it is urgent to monitor the disaster area timely and carry out rescue operations efficiently. However, conventional space observers cannot achieve sufficient spatiotemporal resolution. As spaceborne GNSS-R technique can observe the Earth\u2019s surface with high temporal and spatial resolutions; and it is expected to provide a new solution to the problem of flood hazards. During 19\u201321 July 2021, Henan province, China, suffered a catastrophic flood and urban waterlogging. In order to test the feasibility of flood disaster monitoring on a daily basis by using GNSS-R observations, the CYGNSS (Cyclone Global Navigation Satellite System) Level 1 Science Data were processed for a few days before and after the flood to obtain surface reflectivity by correcting the analog power. Afterwards, the flood was monitored and mapped daily based on the analysis of changes in surface reflectivity from spaceborne GNSS-R mission. The results were evaluated based on the image from MODIS (Moderate Resolution Imaging Spectroradiometer) data, and compared with the observations of SMAP (Soil Moisture Active Passive) in the same period. The results show that the area with high CYGNSS reflectivity corresponds to the flooded area monitored by MODIS, and it is also in high agreement with SMAP. Moreover, CYGNSS can achieve more detailed mapping and quantification of the inundated area and the duration of the flood, respectively, in line with the specific situation of the flood. Thus, spaceborne GNSS-R technology can be used as a method to monitor floods with high temporal resolution.<\/jats:p>","DOI":"10.3390\/rs13224561","type":"journal-article","created":{"date-parts":[[2021,11,14]],"date-time":"2021-11-14T20:51:53Z","timestamp":1636923113000},"page":"4561","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Daily Flood Monitoring Based on Spaceborne GNSS-R Data: A Case Study on Henan, China"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8034-4716","authenticated-orcid":false,"given":"Wentao","family":"Yang","sequence":"first","affiliation":[{"name":"Institute of Space Science, Shandong University, Weihai 264209, China"},{"name":"School of Geological Engineering and Surveying and Mapping, Chang\u2019an University, Xi\u2019an 710054, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fan","family":"Gao","sequence":"additional","affiliation":[{"name":"Institute of Space Science, Shandong University, Weihai 264209, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5818-6264","authenticated-orcid":false,"given":"Tianhe","family":"Xu","sequence":"additional","affiliation":[{"name":"Institute of Space Science, Shandong University, Weihai 264209, China"},{"name":"School of Geological Engineering and Surveying and Mapping, Chang\u2019an University, Xi\u2019an 710054, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nazi","family":"Wang","sequence":"additional","affiliation":[{"name":"Institute of Space Science, Shandong University, Weihai 264209, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinsheng","family":"Tu","sequence":"additional","affiliation":[{"name":"College of Geographic Information and Tourism, Chuzhou University, Chuzhou 239004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lili","family":"Jing","sequence":"additional","affiliation":[{"name":"Institute of Space Science, Shandong University, Weihai 264209, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yahui","family":"Kong","sequence":"additional","affiliation":[{"name":"Institute of Space Science, Shandong University, Weihai 264209, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,13]]},"reference":[{"key":"ref_1","unstructured":"Messner, F., and Meyer, V. 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