{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,6]],"date-time":"2026-06-06T08:01:28Z","timestamp":1780732888111,"version":"3.54.1"},"reference-count":84,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2022,5,19]],"date-time":"2022-05-19T00:00:00Z","timestamp":1652918400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"ESA CCI+","award":["4000126684\/19\/I-NB"],"award-info":[{"award-number":["4000126684\/19\/I-NB"]}]},{"name":"TAPAS TOSCA\/CNES","award":["4000126684\/19\/I-NB"],"award-info":[{"award-number":["4000126684\/19\/I-NB"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Soil moisture is an essential parameter for a better understanding of water processes in the soil\u2013vegetation\u2013atmosphere continuum. Satellite synthetic aperture radar (SAR) is well suited for monitoring water content at fine spatial resolutions on the order of 1 km or higher. Several methodologies are often considered in the inversion of SAR signals: machine learning techniques, such as neural networks, empirical models and change detection methods. In this study, we propose two hybrid methodologies by improving a change detection approach with vegetation consideration or by combining a change detection approach together with a neural network algorithm. The methodology is based on Sentinel-1 and Sentinel-2 data with the use of numerous metrics, including vertical\u2013vertical (VV) and vertical\u2013horizontal (VH) polarization radar signals, the classical change detection surface soil moisture (SSM) index ISSM, radar incidence angle, normalized difference vegetation index (NDVI) optical index, and the VH\/VV ratio. Those approaches are tested using in situ data from the ISMN (International Soil Moisture Network) with observations covering different climatic contexts. The results show an improvement in soil moisture estimations using the hybrid algorithms, in particular the change detection with the neural network one, for which the correlation increases by 54% and 33% with respect to that of the neural network or change detection alone, respectively.<\/jats:p>","DOI":"10.3390\/rs14102434","type":"journal-article","created":{"date-parts":[[2022,5,20]],"date-time":"2022-05-20T00:18:11Z","timestamp":1653005891000},"page":"2434","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Hybrid Methodology Using Sentinel-1\/Sentinel-2 for Soil Moisture Estimation"],"prefix":"10.3390","volume":"14","author":[{"given":"Simon","family":"Nativel","sequence":"first","affiliation":[{"name":"CESBIO, CNES\/CNRS\/INRAE\/IRD\/UPS, Universit\u00e9 de Toulouse, 18 Av. Edouard Belin, Bpi 2801, CEDEX 9, 31401 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emna","family":"Ayari","sequence":"additional","affiliation":[{"name":"CESBIO, CNES\/CNRS\/INRAE\/IRD\/UPS, Universit\u00e9 de Toulouse, 18 Av. Edouard Belin, Bpi 2801, CEDEX 9, 31401 Toulouse, France"},{"name":"National Agronomic Institute of Tunisia, Carthage University, Tunis 1082, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3796-149X","authenticated-orcid":false,"given":"Nemesio","family":"Rodriguez-Fernandez","sequence":"additional","affiliation":[{"name":"CESBIO, CNES\/CNRS\/INRAE\/IRD\/UPS, Universit\u00e9 de Toulouse, 18 Av. Edouard Belin, Bpi 2801, CEDEX 9, 31401 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9461-4120","authenticated-orcid":false,"given":"Nicolas","family":"Baghdadi","sequence":"additional","affiliation":[{"name":"CIRAD, CNRS, INRAE, TETIS, University of Montpellier, AgroParisTech, CEDEX 5, 34093 Montpellier, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Remi","family":"Madelon","sequence":"additional","affiliation":[{"name":"CESBIO, CNES\/CNRS\/INRAE\/IRD\/UPS, Universit\u00e9 de Toulouse, 18 Av. Edouard Belin, Bpi 2801, CEDEX 9, 31401 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Clement","family":"Albergel","sequence":"additional","affiliation":[{"name":"European Space Agency Climate Office, ECSAT, Harwell Campus, Oxforshire, Didcot OX11 0FD, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6141-8222","authenticated-orcid":false,"given":"Mehrez","family":"Zribi","sequence":"additional","affiliation":[{"name":"CESBIO, CNES\/CNRS\/INRAE\/IRD\/UPS, Universit\u00e9 de Toulouse, 18 Av. Edouard Belin, Bpi 2801, CEDEX 9, 31401 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1138","DOI":"10.1126\/science.1100217","article-title":"Regions of Strong Coupling Between Soil Moisture and Precipitation","volume":"305","author":"Koster","year":"2004","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1415","DOI":"10.5194\/hess-12-1415-2008","article-title":"Analysis of surface and root-zone soil moisture dynamics with ERS scatterometer and the hydrometeorological model SAFRAN-ISBA-MODCOU at Grand Morin watershed (France)","volume":"12","author":"Anguela","year":"2008","journal-title":"Hydrol. Earth Syst. 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