{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T01:15:37Z","timestamp":1772759737785,"version":"3.50.1"},"reference-count":48,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2014,10,28]],"date-time":"2014-10-28T00:00:00Z","timestamp":1414454400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Chinese 973 program","award":["2013CB733404"],"award-info":[{"award-number":["2013CB733404"]}]},{"name":"Dragon III Project","award":["10448"],"award-info":[{"award-number":["10448"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41101395"],"award-info":[{"award-number":["41101395"]}],"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>Spatial monitoring of the sowing date plays an important role in crop yield estimation at the regional scale. The feasibility of using polarimetric synthetic aperture radar (SAR) data for early season monitoring of the sowing dates of oilseed rape (Brassica napus L.) fields is explored in this paper. Polarimetric SAR responses of six parameters, relying on polarization decomposition methods, were investigated as a function of days after sowing (DAS) during the entire growing season, by means of five consecutive Radarsat-2 images. A near-continuous temporal evolution of these parameters was observed, based on 88 oilseed rape fields. It provided a solid basis for determining the suitable temporal window and the best polarimetric parameters for sowing date monitoring. A high sensitivity of all polarimetric parameters to the DAS at different growing stages was shown. Simple linear models could be calibrated to estimate sowing dates at early growth stages and were validated on an independent data set. Although Volume and Span parameters provided the highest sowing date estimation accuracy at the earlier growth stages, the other four parameters (Volume\/Total, Odd\/Total, Entropy and Alpha) were more accurate for a wider temporal window. These results demonstrate the capability and high potential of polarimetric SAR data for monitoring the sowing date of crops in the early season.<\/jats:p>","DOI":"10.3390\/rs61110375","type":"journal-article","created":{"date-parts":[[2014,10,28]],"date-time":"2014-10-28T10:25:07Z","timestamp":1414491907000},"page":"10375-10394","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Temporal Polarimetric Behavior of Oilseed Rape (Brassica napus L.) at C-Band for Early Season Sowing Date Monitoring"],"prefix":"10.3390","volume":"6","author":[{"given":"Hao","family":"Yang","sequence":"first","affiliation":[{"name":"Institute of Forest Resource Information Techniques, Chinese Academy of Forestry,  Beijing 100091, China"},{"name":"Beijing Research Center for Information Technology in Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China"}]},{"given":"Zengyuan","family":"Li","sequence":"additional","affiliation":[{"name":"Institute of Forest Resource Information Techniques, Chinese Academy of Forestry,  Beijing 100091, China"}]},{"given":"Erxue","family":"Chen","sequence":"additional","affiliation":[{"name":"Institute of Forest Resource Information Techniques, Chinese Academy of Forestry,  Beijing 100091, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1448-5091","authenticated-orcid":false,"given":"Chunjiang","family":"Zhao","sequence":"additional","affiliation":[{"name":"Beijing Research Center for Information Technology in Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China"}]},{"given":"Guijun","family":"Yang","sequence":"additional","affiliation":[{"name":"Beijing Research Center for Information Technology in Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3091-7680","authenticated-orcid":false,"given":"Raffaele","family":"Casa","sequence":"additional","affiliation":[{"name":"Department of Agriculture, Forests, Nature and Energy (DAFNE), Universita' della Tuscia,  Viterbo 01100, Italy"}]},{"given":"Stefano","family":"Pignatti","sequence":"additional","affiliation":[{"name":"Institute of Methodologies for Environmental Analysis, Consiglio Nazionale delle Ricerche,  Tito Scalo (PZ) 85050, Italy"}]},{"given":"Qi","family":"Feng","sequence":"additional","affiliation":[{"name":"Institute of Forest Resource Information Techniques, Chinese Academy of Forestry,  Beijing 100091, China"}]}],"member":"1968","published-online":{"date-parts":[[2014,10,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/0378-4290(94)90096-5","article-title":"Date of sowing effects on grain-yield and yield components of irrigated spring wheat cultivars and relationships with radiation and temperature in Ludhiana, India","volume":"37","author":"Dhillon","year":"1994","journal-title":"Field Crops Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.fcr.2006.09.012","article-title":"Remote sensing assessment of regional yield losses due to sub-optimal planting dates and fallow period weed management","volume":"101","author":"Lobell","year":"2007","journal-title":"Field Crops Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.agsy.2012.09.003","article-title":"Satellite detection of earlier wheat sowing in India and implications for yield trends","volume":"115","author":"Lobell","year":"2013","journal-title":"Agric. 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