{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T22:57:21Z","timestamp":1768258641995,"version":"3.49.0"},"reference-count":40,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2021,8,10]],"date-time":"2021-08-10T00:00:00Z","timestamp":1628553600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000844","name":"European Space Agency","doi-asserted-by":"publisher","award":["4000107360\/12\/I-492LG"],"award-info":[{"award-number":["4000107360\/12\/I-492LG"]}],"id":[{"id":"10.13039\/501100000844","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100010890","name":"Chinese Government Scholarship","doi-asserted-by":"publisher","award":["xxxx"],"award-info":[{"award-number":["xxxx"]}],"id":[{"id":"10.13039\/501100010890","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Rain Signatures on C-band Synthetic Aperture Radar (SAR) images acquired over ocean are common and can dominate the backscattered signal from the ocean surface. In many cases, the inability to decipher between ocean and rain signatures can disturb the analysis of SAR scenes for maritime applications. This study relies on Sentinel-1 SAR acquisitions in the Interferometric Wide swath mode and high-resolution measurements from ground-based weather radar to document the rain impact on the radar backscattered signal in both co- and cross-polarization channels. The dark and bright rain signatures are found in connection with the timeliness of the rain cells. In particular, the bright patches are demonstrated by the hydrometeors (graupels, hails) in the melting layer. In general, the radar backscatter under rain increases with rain rate for a given sea state and decreases when the sea state strengthens. The rain also has a stronger impact on the radar signal in both polarizations when the incidence angle increases. The complementary sensitivity of the SAR signal of rain in both channels is then used to derive a filter to locate the areas in SAR scenes where the signal is not dominated by rain. The filter optimized to match the rain observed by the ground-based weather radar is more efficient when both polarization channels are considered. Case studies are presented to discuss the advantages and limitations of such a filtering approach.<\/jats:p>","DOI":"10.3390\/rs13163155","type":"journal-article","created":{"date-parts":[[2021,8,10]],"date-time":"2021-08-10T08:57:14Z","timestamp":1628585834000},"page":"3155","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Automated Rain Detection by Dual-Polarization Sentinel-1 Data"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7277-9063","authenticated-orcid":false,"given":"Yuan","family":"Zhao","sequence":"first","affiliation":[{"name":"Laboratoire d\u2019Oc\u00e9anographie Physique et Spatiale (LOPS), Ifremer, 29280 Plouzan\u00e9, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6832-3274","authenticated-orcid":false,"given":"Nicolas","family":"Long\u00e9p\u00e9","sequence":"additional","affiliation":[{"name":"ESA, 00044 Frascati, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1250-4436","authenticated-orcid":false,"given":"Alexis","family":"Mouche","sequence":"additional","affiliation":[{"name":"Laboratoire d\u2019Oc\u00e9anographie Physique et Spatiale (LOPS), Ifremer, 29280 Plouzan\u00e9, France"}]},{"given":"Romain","family":"Husson","sequence":"additional","affiliation":[{"name":"CLS, 29280 Plouzan\u00e9, France"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,10]]},"reference":[{"key":"ref_1","unstructured":"Fu, L.L., and Holt, B. (1982). Seasat Views Oceans and Sea Ice with Synthetic-Aperture Radar, Jet Propulsion Laboratory, California Institute of Technology."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"112031","DOI":"10.1016\/j.rse.2020.112031","article-title":"An assessment of marine atmospheric boundary layer roll detection using Sentinel-1 SAR data","volume":"250","author":"Wang","year":"2020","journal-title":"Remote Sens. Environ."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Fan, S., Kudryavtsev, V., Zhang, B., Perrie, W., Chapron, B., and Mouche, A. (2019). On C-Band Quad-Polarized Synthetic Aperture Radar Properties of Ocean Surface Currents. Remote Sens., 11.","DOI":"10.3390\/rs11192321"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"8362","DOI":"10.1109\/TGRS.2019.2920750","article-title":"On quad-polarized SAR measurements of the ocean surface","volume":"57","author":"Kudryavtsev","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"6046","DOI":"10.1002\/2014JC010173","article-title":"Quad-polarization SAR features of ocean currents","volume":"119","author":"Kudryavtsev","year":"2014","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"46","DOI":"10.5670\/oceanog.2013.30","article-title":"Tropical cyclone winds retrieved from synthetic aperture radar","volume":"26","author":"Horstmann","year":"2013","journal-title":"Oceanography"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"272","DOI":"10.1175\/JTECH-D-13-00006.1","article-title":"High-resolution hurricane vector winds from C-band dual-polarization SAR observations","volume":"31","author":"Zhang","year":"2014","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6746","DOI":"10.1109\/TGRS.2017.2732508","article-title":"Combined co-and cross-polarized SAR measurements under extreme wind conditions","volume":"55","author":"Mouche","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4929","DOI":"10.1109\/JSTARS.2016.2587840","article-title":"Wave breaking in slicks: Impacts on C-band quad-polarized SAR measurements","volume":"9","author":"Hansen","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/j.rse.2017.10.032","article-title":"X-, C-, and L-band SAR signatures of newly formed sea ice in Arctic leads during winter and spring","volume":"204","author":"Johansson","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4050","DOI":"10.1109\/TGRS.2018.2889519","article-title":"Comparative evaluation of sea ice lead detection based on SAR imagery and altimeter data","volume":"57","author":"Thibaut","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3040","DOI":"10.1109\/TGRS.2020.3007789","article-title":"Extraction of Sea Ice Cover by Sentinel-1 SAR Based on Support Vector Machine With Unsupervised Generation of Training Data","volume":"59","author":"Li","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"5831","DOI":"10.1109\/JSTARS.2021.3074068","article-title":"Prediction of categorized Sea Ice Concentration from Sentinel-1 SAR images based on a Fully Convolutional Network","volume":"14","author":"Gelis","year":"2021","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"18867","DOI":"10.1029\/98JC00779","article-title":"Investigation of multifrequency\/multipolarization radar signatures of rain cells over the ocean using SIR-C\/X-SAR data","volume":"103","author":"Melsheimer","year":"1998","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"937","DOI":"10.1109\/36.921411","article-title":"An ERS-1 synthetic aperture radar image of a tropical squall line compared with weather radar data","volume":"39","author":"Lin","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3507","DOI":"10.1109\/TGRS.2009.2022271","article-title":"Assessment of Atmospheric Propagation Effects in SAR Images","volume":"47","author":"Danklmayer","year":"2009","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.rse.2016.10.015","article-title":"Rain footprints on C-band synthetic aperture radar images of the ocean-Revisited","volume":"187","author":"Alpers","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1080\/01431160500239214","article-title":"Multi-frequency scatterometer measurements on water surfaces agitated by artificial and natural rain","volume":"27","author":"Braun","year":"2006","journal-title":"Int. J. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1109\/36.628780","article-title":"The effects of rain on TOPEX\/Poseidon altimeter data","volume":"35","author":"Tournadre","year":"1997","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1109\/TAP.1978.1141845","article-title":"The aR b relation in the calculation of rain attenuation","volume":"26","author":"Olsen","year":"1978","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"112177","DOI":"10.1016\/j.rse.2020.112177","article-title":"A note on radar signatures of hydrometeors in the melting layer as inferred from Sentinel-1 SAR data acquired over the ocean","volume":"253","author":"Alpers","year":"2020","journal-title":"Remote Sens. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1519","DOI":"10.1109\/LGRS.2014.2298095","article-title":"Rain identification in ASCAT winds using singularity analysis","volume":"11","author":"Lin","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"4665","DOI":"10.1029\/2000JC000263","article-title":"Simultaneous observations of rain cells over the ocean by the synthetic aperture radar aboard the ERS satellites and by surface-based weather radars","volume":"106","author":"Melsheimer","year":"2001","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1546","DOI":"10.1002\/2015JC010975","article-title":"A study of radar backscattering from water surface in response to rainfall","volume":"121","author":"Liu","year":"2016","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"702","DOI":"10.1109\/TGRS.2003.818811","article-title":"Directional analysis of SAR images aiming at wind direction","volume":"42","author":"Koch","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Long\u00e9p\u00e9, N., Mouche, A., Ferro-Famil, L., and Husson, R. (2021). Co-Cross Polarization Coherence over the Sea Surface from Sentinel-1 SAR Data: Perspectives for Mission Calibration and Wind Field Retrieval. IEEE Trans. Geosci. Remote Sens.","DOI":"10.1109\/TGRS.2021.3055979"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1175\/1520-0469(1948)005<0165:TDORWS>2.0.CO;2","article-title":"The distribution of raindrops with size","volume":"5","author":"Marshall","year":"1948","journal-title":"J. Meteor."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1364","DOI":"10.1126\/science.266.5189.1364","article-title":"Origin of storm footprints on the sea seen by synthetic aperture radar","volume":"266","author":"Atlas","year":"1994","journal-title":"Science"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1109\/JOE.1979.1145408","article-title":"Preliminary study of rain effects on radar scattering from water surfaces","volume":"4","author":"Moore","year":"1979","journal-title":"IEEE J. Ocean. Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1080\/014311697219385","article-title":"Rain generated ring-waves: Measurements and modelling for remote sensing","volume":"18","author":"Bliven","year":"1997","journal-title":"Int. J. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/S0034-4257(96)00159-9","article-title":"SIR-C\/X-SAR observations of rain storms","volume":"59","author":"Jameson","year":"1997","journal-title":"Remote Sens. Environ."},{"key":"ref_32","first-page":"86","article-title":"Wind fields from SAR: Could they improve our understanding of storm dynamics?","volume":"21","author":"Katsaros","year":"2000","journal-title":"Johns Hopkins Apl Tech. Dig."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1078","DOI":"10.1038\/1701078b0","article-title":"Cross-polarization of the radar melting-band","volume":"170","author":"Browne","year":"1952","journal-title":"Nature"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"908","DOI":"10.1175\/1520-0426(1989)006<0908:TIAMAO>2.0.CO;2","article-title":"The interpretation and meteorological application of radar backscatter amplitude ratios at linear polarizations","volume":"6","author":"Jameson","year":"1989","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_35","unstructured":"(2005). Federal Meteorologica Handbook No. 11, Doppler Radar Meteorological Observations. Part B, Doppler Radar Theory and Meteorology, Technical Report."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1109\/LGRS.2010.2085417","article-title":"C-band cross-polarization wind speed retrieval","volume":"8","author":"Vachon","year":"2010","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"7195","DOI":"10.1002\/2015JC011149","article-title":"Global C-Band Envisat, RADARSAT-2 and Sentinel-1 SAR measurements in copolarization and cross-polarization","volume":"120","author":"Mouche","year":"2015","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"952","DOI":"10.1109\/10.846690","article-title":"Receiver operating characteristic analysis for intelligent medical systems-a new approach for finding confidence intervals","volume":"47","author":"Tilbury","year":"2000","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1002\/1097-0142(1950)3:1<32::AID-CNCR2820030106>3.0.CO;2-3","article-title":"Index for rating diagnostic tests","volume":"3","author":"Youden","year":"1950","journal-title":"Cancer"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"7961","DOI":"10.1029\/94JC00250","article-title":"Footprints of storms on the sea: A view from spaceborne synthetic aperture radar","volume":"99","author":"Atlas","year":"1994","journal-title":"J. Geophys. Res. Ocean."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/16\/3155\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:43:16Z","timestamp":1760164996000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/16\/3155"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,8,10]]},"references-count":40,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2021,8]]}},"alternative-id":["rs13163155"],"URL":"https:\/\/doi.org\/10.3390\/rs13163155","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,8,10]]}}}