{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,24]],"date-time":"2026-01-24T16:49:33Z","timestamp":1769273373509,"version":"3.49.0"},"reference-count":42,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2018,1,22]],"date-time":"2018-01-22T00:00:00Z","timestamp":1516579200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Rice is a major staple food for nearly half of the world\u2019s population and has a considerable contribution to the global agricultural economy. While spaceborne Synthetic Aperture Radar (SAR) data have proved to have great potential to provide rice cultivation area, few studies have been performed to provide practical information that meets the user requirements. In rice growing regions where the inter-field crop calendar is not uniform such as in the Mekong Delta in Vietnam, knowledge of the start of season on a field basis, along with the planted rice varieties, is very important for correct field management (timing of irrigation, fertilization, chemical treatment, harvest), and for market assessment of the rice production. The objective of this study is to develop methods using SAR data to retrieve in addition to the rice grown area, the sowing date, and the distinction between long and short cycle varieties. This study makes use of X-band SAR data from COSMO-SkyMed acquired from 19 August to 23 November 2013 covering the Chau Thanh and Thoai Son districts in An Giang province, Viet Nam, characterized by a complex cropping pattern. The SAR data have been analyzed as a function of rice parameters, and the temporal and polarization behaviors of the radar backscatter of different rice varieties have been interpreted physically. New backscatter indicators for the detection of rice paddy area, the estimation of the sowing date, and the mapping of the short cycle and long cycle rice varieties have been developed and assessed. Good accuracy has been found with 92% in rice grown area, 96% on rice long or short cycle, and a root mean square error of 4.3 days in sowing date. The results have been discussed regarding the generality of the methods with respect to the rice cultural practices and the SAR data characteristics.<\/jats:p>","DOI":"10.3390\/s18010316","type":"journal-article","created":{"date-parts":[[2018,1,22]],"date-time":"2018-01-22T13:40:39Z","timestamp":1516628439000},"page":"316","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":63,"title":["Mapping of Rice Varieties and Sowing Date Using X-Band SAR Data"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9685-6281","authenticated-orcid":false,"given":"Hoa","family":"Phan","sequence":"first","affiliation":[{"name":"Centre d\u2019Etudes Spatiales de la Biosph\u00e8re (CESBIO), 31401 Toulouse, France"},{"name":"Telespazio France, 31023 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thuy","family":"Le Toan","sequence":"additional","affiliation":[{"name":"Centre d\u2019Etudes Spatiales de la Biosph\u00e8re (CESBIO), 31401 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7428-4339","authenticated-orcid":false,"given":"Alexandre","family":"Bouvet","sequence":"additional","affiliation":[{"name":"Centre d\u2019Etudes Spatiales de la Biosph\u00e8re (CESBIO), 31401 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lam","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Space Technology Application Center, Ho Chi Minh City 700000, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tien","family":"Pham Duy","sequence":"additional","affiliation":[{"name":"An Giang University, An Giang 880000, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6141-8222","authenticated-orcid":false,"given":"Mehrez","family":"Zribi","sequence":"additional","affiliation":[{"name":"Centre d\u2019Etudes Spatiales de la Biosph\u00e8re (CESBIO), 31401 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,1,22]]},"reference":[{"key":"ref_1","unstructured":"(2014, November 02). Rice Market Monitor. Available online: http:\/\/www.fao.org\/3\/a-i4147e.pdf."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"769","DOI":"10.3390\/s150100769","article-title":"Application of remote sensors in mapping rice area and forecasting its production: A review","volume":"15","author":"Mosleh","year":"2015","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2101","DOI":"10.1080\/01431161.2012.738946","article-title":"Remote sensing of rice crop areas","volume":"34","author":"Kuenzer","year":"2013","journal-title":"Int. J. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1109\/36.551933","article-title":"Rice crop mapping and monitoring using ERS-1 data based on experiment and modeling results","volume":"35","author":"Ribbes","year":"1997","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1080\/014311699213172","article-title":"Rice field mapping and monitoring with RADARSAT data","volume":"20","author":"Ribbes","year":"1999","journal-title":"Int. J. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1016\/S0034-4257(00)00212-1","article-title":"Rice monitoring and production estimation using multitemporal RADARSAT","volume":"76","author":"Shao","year":"2001","journal-title":"Remote Sens. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"517","DOI":"10.1109\/TGRS.2008.2007963","article-title":"Monitoring of the Rice Cropping System in the Mekong Delta Using ENVISAT\/ASAR Dual Polarisation Data","volume":"47","author":"Bouvet","year":"2009","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1090","DOI":"10.1016\/j.rse.2010.12.014","article-title":"Use of ENVISAT\/ASAR wide-swath data for timely rice fields mapping in the Mekong River Delta","volume":"115","author":"Bouvet","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"33563","DOI":"10.1117\/1.3271046","article-title":"Effects of changing cultural practices on C-band SAR backscatter using Envisat ASAR data in the Mekong River Delta","volume":"3","author":"Apan","year":"2009","journal-title":"J. Appl. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Torbick, N., Chowdhury, D., Salas, W., and Qi, J. (2017). Monitoring Rice Agriculture across Myanmar Using Time Series Sentinel-1 Assisted by Landsat-8 and PALSAR-2. Remote Sens., 9.","DOI":"10.3390\/rs9020119"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Yuzugullu, O., Marelli, S., Erten, E., Sudret, B., and Hajnsek, I. (2017). Determining Rice Growth Stage with X-Band SAR: A Metamodel Based Inversion. Remote Sens., 9.","DOI":"10.3390\/rs9050460"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.rse.2017.02.004","article-title":"Retrieval of vegetation height in rice fields using polarimetric SAR interferometry with TanDEM-X data","volume":"192","author":"Erten","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_13","first-page":"012015","article-title":"Synthetic Aperture Radar (SAR)-based paddy rice monitoring system: Development and application in key rice producing areas in Tropical Asia","volume":"Volume 54","author":"Setiyono","year":"2017","journal-title":"IOP Conference Series: Earth and Environmental Science"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1109\/TGRS.1989.1398243","article-title":"Multitemporal and dual-polarization observations of agricultural vegetation covers by X-band SAR images","volume":"27","author":"Laur","year":"1989","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/0034-4257(91)90081-G","article-title":"Crop parameter estimation from ground-based x-band (3-cm wave) radar backscattering data","volume":"37","author":"Bouman","year":"1991","journal-title":"Remote Sens. Environ."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2695","DOI":"10.1109\/TGRS.2011.2176740","article-title":"Rice phenology monitoring by means of SAR polarimetry at X-band","volume":"50","author":"Cloude","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1109\/JSTARS.2010.2047634","article-title":"First results of rice monitoring practices in Spain by means of time series of TerraSAR-X dual-pol images","volume":"4","author":"Hajnsek","year":"2011","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"10773","DOI":"10.3390\/rs61110773","article-title":"Towards an operational SAR-based rice monitoring system in Asia: Examples from 13 demonstration sites across Asia in the RIICE project","volume":"6","author":"Nelson","year":"2014","journal-title":"Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1080\/01431161.2015.1131902","article-title":"A study of the use of COSMO-SkyMed SAR PingPong polarimetric mode for rice growth monitoring","volume":"37","author":"Corcione","year":"2016","journal-title":"Int. J. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.rse.2013.09.001","article-title":"Capability of C-band backscattering coefficients from high-resolution satellite SAR sensors to assess biophysical variables in paddy rice","volume":"140","author":"Inoue","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"15868","DOI":"10.3390\/rs71215808","article-title":"Mapping Rice Seasonality in the Mekong Delta with Multi-Year Envisat ASAR WSM Data","volume":"7","author":"Nguyen","year":"2015","journal-title":"Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1412","DOI":"10.1109\/36.718845","article-title":"Application of multitemporal ERS-2 synthetic aperture radar in delineating rice cropping systems in the Mekong River Delta, Vietnam","volume":"36","author":"Liew","year":"1998","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2953","DOI":"10.1080\/014311697217143","article-title":"The identification of rice fields using multi-temporal ERS-1 C band SAR data","volume":"18","author":"Kurosu","year":"1997","journal-title":"Int. J. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"5995","DOI":"10.3390\/rs6075995","article-title":"Potential of X-band images from high-resolution satellite SAR sensors to assess growth and yield in paddy rice","volume":"6","author":"Inoue","year":"2014","journal-title":"Remote Sens."},{"key":"ref_25","unstructured":"(2016, December 29). General Statistics Office of Viet Nam, Available online: https:\/\/www.gso.gov.vn\/."},{"key":"ref_26","unstructured":"(2016, December 29). An Giang Department of Agriculture and Rural Development, Available online: http:\/\/www.angiang.gov.vn\/wps\/portal\/."},{"key":"ref_27","unstructured":"(2017, January 10). Ho Chi Minh City Food Joint Stock Company. Available online: http:\/\/www.foodcosa.vn\/index.php\/vi\/tin-noi-bo-01\/239-t-ng-h-p-th-tru-ng-lua-g-o-ngay-23\u201303."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"130","DOI":"10.1016\/j.rse.2016.10.007","article-title":"Retrieval of agricultural crop height from space: A comparison of SAR techniques","volume":"187","author":"Erten","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1109\/36.239913","article-title":"Change detection techniques for ERS-1 SAR data","volume":"31","author":"Rignot","year":"1993","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"603","DOI":"10.1080\/014311697218962","article-title":"Multi-variate optimal speckle reduction in SAR imagery","volume":"18","author":"Bruniquel","year":"1997","journal-title":"Int. J. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2373","DOI":"10.1109\/36.964973","article-title":"Filtering of multichannel SAR images","volume":"39","author":"Quegan","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.1109\/36.406692","article-title":"Electromagnetic scattering model for a tree trunk above a tilted ground plane","volume":"33","author":"Lin","year":"1995","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_33","unstructured":"Lopez-Sanchez, J.M., Ballester-Berman, J.D., Paya, S., Cazcarra, V., and Navarro, V.D. (2010, January 7\u201310). An advanced electromagnetic model for rice fields at X-band: Development and interpretation of dual-pol TerraSAR-X images. Proceedings of the 8th European Conference on Synthetic Aperture Radar (EUSAR), Aachen, Germany."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.rse.2005.10.004","article-title":"Mapping paddy rice agriculture in South and Southeast Asia using multi-temporal MODIS images","volume":"100","author":"Xiao","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3512","DOI":"10.1109\/JSTARS.2016.2539498","article-title":"Contribution to real-time estimation of crop phenological states in a dynamical framework based on NDVI time series: Data fusion with SAR and temperature","volume":"9","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Guan, X., Huang, C., Liu, G., Meng, X., and Liu, Q. (2016). Mapping rice cropping systems in Vietnam using an NDVI-based time-series similarity measurement based on DTW distance. Remote Sens., 8.","DOI":"10.3390\/rs8010019"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/S0034-4257(01)00343-1","article-title":"Season-long daily measurements of multifrequency (Ka, Ku, X, C, and L) and full-polarization backscatter signatures over paddy rice field and their relationship with biological variables","volume":"81","author":"Inoue","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3521","DOI":"10.1109\/TGRS.2010.2047399","article-title":"An end-to-end error model for classification methods based on temporal change or polarization ratio of SAR intensities","volume":"48","author":"Bouvet","year":"2010","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"4643","DOI":"10.1080\/01431160802632249","article-title":"Multi-year monitoring of rice crop phenology through time series analysis of MODIS images","volume":"30","author":"Boschetti","year":"2009","journal-title":"Int. J. Remote Sens."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"De Bernardis, C.G., Vicente-Guijalba, F., Martinez-Marin, T., and Lopez-Sanchez, J.M. (2016). Particle Filter Approach for Real-Time Estimation of Crop Phenological States Using Time Series of NDVI Images. Remote Sens., 8.","DOI":"10.3390\/rs8070610"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1008","DOI":"10.1109\/JSTARS.2014.2372898","article-title":"Estimation of Key Dates and Stages in Rice Crops using Dual-Polarisation SAR Time Series and a Particle Filtering Approach","volume":"8","year":"2015","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.rse.2014.02.015","article-title":"Good practices for estimating area and assessing accuracy of land change","volume":"148","author":"Olofsson","year":"2014","journal-title":"Remote Sens. Environ."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/1\/316\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:52:08Z","timestamp":1760194328000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/1\/316"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,1,22]]},"references-count":42,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2018,1]]}},"alternative-id":["s18010316"],"URL":"https:\/\/doi.org\/10.3390\/s18010316","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,1,22]]}}}