{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T17:45:37Z","timestamp":1772300737379,"version":"3.50.1"},"reference-count":33,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2021,3,17]],"date-time":"2021-03-17T00:00:00Z","timestamp":1615939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"2017 ESA S3 challenge and Copernicus Masters overall winner award (\u201cFSSCat\u201d project)","award":["(\u201cFSSCat\u201d project)"],"award-info":[{"award-number":["(\u201cFSSCat\u201d project)"]}]},{"name":"SPOT: Sensing with Pioneering Opportunistic Techniques","award":["RTI2018-099008-B-C21 \/ AEI \/ 10.13039\/501100011033"],"award-info":[{"award-number":["RTI2018-099008-B-C21 \/ AEI \/ 10.13039\/501100011033"]}]},{"name":"Unidad de Excelencia Maria de Maeztu","award":["MDM-2016-0600"],"award-info":[{"award-number":["MDM-2016-0600"]}]},{"DOI":"10.13039\/501100004837","name":"Spanish Ministry of Science and Innovation","doi-asserted-by":"publisher","award":["ESP2017-89463-C3"],"award-info":[{"award-number":["ESP2017-89463-C3"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Centro de Excelencia Severo Ochoa","award":["CEX2019-000928-S"],"award-info":[{"award-number":["CEX2019-000928-S"]}]},{"name":"FPU fellowship from the Spanish Ministry of Education","award":["FPU18\/06107"],"award-info":[{"award-number":["FPU18\/06107"]}]},{"name":"AGAUR - Generalitat de Catalunya (FEDER)","award":["FI-DGR 2018"],"award-info":[{"award-number":["FI-DGR 2018"]}]},{"name":"\u201cla Caixa\u201d Foundation (ID 100010434)","award":["LCF\/BQ\/DI18\/11660050"],"award-info":[{"award-number":["LCF\/BQ\/DI18\/11660050"]}]},{"name":"European Union\u2019s Horizon 2020 research and innovation programme","award":["Marie Sklodowska-Curie grant agreement No. 713673"],"award-info":[{"award-number":["Marie Sklodowska-Curie grant agreement No. 713673"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>CubeSat-based Earth Observation missions have emerged in recent times, achieving scientifically valuable data at a moderate cost. FSSCat is a two 6U CubeSats mission, winner of the ESA S3 challenge and overall winner of the 2017 Copernicus Masters Competition, that was launched in September 2020. The first satellite, 3Cat-5\/A, carries the FMPL-2 instrument, an L-band microwave radiometer and a GNSS-Reflectometer. This work presents a neural network approach for retrieving sea ice concentration and sea ice extent maps on the Arctic and the Antarctic oceans using FMPL-2 data. The results from the first months of operations are presented and analyzed, and the quality of the retrieved maps is assessed by comparing them with other existing sea ice concentration maps. As compared to OSI SAF products, the overall accuracy for the sea ice extent maps is greater than 97% using MWR data, and up to 99% when using combined GNSS-R and MWR data. In the case of Sea ice concentration, the absolute errors are lower than 5%, with MWR and lower than 3% combining it with the GNSS-R. The total extent area computed using this methodology is close, with 2.5% difference, to those computed by other well consolidated algorithms, such as OSI SAF or NSIDC. The approach presented for estimating sea ice extent and concentration maps is a cost-effective alternative, and using a constellation of CubeSats, it can be further improved.<\/jats:p>","DOI":"10.3390\/rs13061139","type":"journal-article","created":{"date-parts":[[2021,3,17]],"date-time":"2021-03-17T11:48:22Z","timestamp":1615981702000},"page":"1139","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["Sea Ice Concentration and Sea Ice Extent Mapping with L-Band Microwave Radiometry and GNSS-R Data from the FFSCat Mission Using Neural Networks"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4917-5798","authenticated-orcid":false,"given":"David","family":"Llaveria","sequence":"first","affiliation":[{"name":"CommSensLab Unidad Mar\u00eda de Maeztu\u2014Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6441-6676","authenticated-orcid":false,"given":"Juan Francesc","family":"Munoz-Martin","sequence":"additional","affiliation":[{"name":"CommSensLab Unidad Mar\u00eda de Maeztu\u2014Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2578-8522","authenticated-orcid":false,"given":"Christoph","family":"Herbert","sequence":"additional","affiliation":[{"name":"CommSensLab Unidad Mar\u00eda de Maeztu\u2014Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2694-7107","authenticated-orcid":false,"given":"Miriam","family":"Pablos","sequence":"additional","affiliation":[{"name":"Physical and Technological Oceanography Group, Institut de Ci\u00e8ncies del Mar, Consejo Superior de Investigaciones Cient\u00edficas (ICM-CSIC), 08003 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0031-0802","authenticated-orcid":false,"given":"Hyuk","family":"Park","sequence":"additional","affiliation":[{"name":"CommSensLab Unidad Mar\u00eda de Maeztu\u2014Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9514-4992","authenticated-orcid":false,"given":"Adriano","family":"Camps","sequence":"additional","affiliation":[{"name":"CommSensLab Unidad Mar\u00eda de Maeztu\u2014Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,17]]},"reference":[{"key":"ref_1","unstructured":"NASA\u2019s Jet Propulsion Laboratory (2021, February 20). 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