{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,21]],"date-time":"2026-01-21T08:54:34Z","timestamp":1768985674153,"version":"3.49.0"},"reference-count":48,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2016,6,22]],"date-time":"2016-06-22T00:00:00Z","timestamp":1466553600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Optical and microwave images have been combined for land cover monitoring in different agriculture scenarios, providing useful information on qualitative and quantitative land cover changes. This study aims to assess the complementarity and interoperability of optical (SPOT-5 Take-5) and synthetic aperture radar (SAR) (Sentinel-1A) data for crop parameter (basal crop coefficient (Kcb) values and the length of the crop\u2019s development stages) retrieval and crop type classification, with a focus on crop water requirements, for an irrigation perimeter in Angola. SPOT-5 Take-5 images are used as a proxy of Sentinel-2 data to evaluate the potential of their enhanced temporal resolution for agricultural applications. In situ data are also used to complement the Earth Observation (EO) data. The Normalized Difference Vegetation Index (NDVI) and dual (VV + VH) polarization backscattering time series are used to compute the Kcb curve for four crop types (maize, soybean, bean and pasture) and to estimate the length of each phenological growth stage. The Kcb values are then used to compute the crop\u2019s evapotranspiration and to subsequently estimate the crop irrigation requirements based on a soil water balance model. A significant R2 correlation between NDVI and backscatter time series was observed for all crops, demonstrating that optical data can be replaced by microwave data in the presence of cloud cover. However, it was not possible to properly identify each stage of the crop cycle due to the lack of EO data for the complete growing season.<\/jats:p>","DOI":"10.3390\/rs8060525","type":"journal-article","created":{"date-parts":[[2016,6,23]],"date-time":"2016-06-23T18:29:50Z","timestamp":1466706590000},"page":"525","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":70,"title":["Crop Monitoring Based on SPOT-5 Take-5 and Sentinel-1A Data for the Estimation of Crop Water Requirements"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4207-1611","authenticated-orcid":false,"given":"Ana","family":"Navarro","sequence":"first","affiliation":[{"name":"IDL, Departamento de Engenharia Geogr\u00e1fica, Geof\u00edsica e Energia, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1782-2732","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Rolim","sequence":"additional","affiliation":[{"name":"LEAF, Departamento de Ci\u00eancias e Engenharia de Biossistemas, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal"}]},{"given":"Irina","family":"Miguel","sequence":"additional","affiliation":[{"name":"Departamento de Geologia, Faculdade de Ci\u00eancias, Universidade Agostinho Neto, 1231 Luanda, Angola"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1028-4644","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Catal\u00e3o","sequence":"additional","affiliation":[{"name":"IDL, Departamento de Engenharia Geogr\u00e1fica, Geof\u00edsica e Energia, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"}]},{"given":"Joel","family":"Silva","sequence":"additional","affiliation":[{"name":"NOVA IMS, Information Management School, Universidade Nova de Lisboa, 1070-312 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1136-3387","authenticated-orcid":false,"given":"Marco","family":"Painho","sequence":"additional","affiliation":[{"name":"NOVA IMS, Information Management School, Universidade Nova de Lisboa, 1070-312 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5677-8298","authenticated-orcid":false,"given":"Zolt\u00e1n","family":"Vekerdy","sequence":"additional","affiliation":[{"name":"ITC, Department of Water Resources, Faculty of Geo-information Science and Earth Observation, University of Twente, P.O. Box 6, 7500 AA Enschede, The Netherlands"}]}],"member":"1968","published-online":{"date-parts":[[2016,6,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"10400","DOI":"10.3390\/rs70810400","article-title":"Land cover and crop type classification along the season based on biophysical variables retrieved from multi-sensor high-resolution time series","volume":"7","author":"Waldner","year":"2015","journal-title":"Remote Sens."},{"key":"ref_2","first-page":"1009","article-title":"Multi-date SAR\/TM synergism for crop classification in Western Canada","volume":"61","author":"Brisco","year":"1995","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1080\/014311600210678","article-title":"Land cover discrimination from multitemporal ERS images and multispectral Landsat images: A study case in an agricultural area in France","volume":"21","author":"Quesney","year":"2000","journal-title":"Int. J. 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