{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T14:26:34Z","timestamp":1775658394645,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,23]],"date-time":"2025-05-23T00:00:00Z","timestamp":1747958400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000780","name":"European Union","doi-asserted-by":"publisher","award":["101091616"],"award-info":[{"award-number":["101091616"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000780","name":"European Union","doi-asserted-by":"publisher","award":["UIDB\/04683"],"award-info":[{"award-number":["UIDB\/04683"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000780","name":"European Union","doi-asserted-by":"publisher","award":["UIDP\/04683"],"award-info":[{"award-number":["UIDP\/04683"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["101091616"],"award-info":[{"award-number":["101091616"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/04683"],"award-info":[{"award-number":["UIDB\/04683"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UIDP\/04683"],"award-info":[{"award-number":["UIDP\/04683"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Remote sensing applications for marine placer deposit exploration remain limited due to the mineralogical complexity and dynamic coastal processes. This study presents the first medium- to high-level detailed multi-scale remote sensing analysis of placer deposits in the R\u00edas Baixas, NW Spain, focusing on five beaches within the Vigo Estuary. Ten beach samples were analyzed for their heavy mineral (HM) content and spectral signatures, using bromoform separation and FieldSpec 4 spectroradiometer equipment, respectively. The spectral signatures of beach samples with a high HM content were characterized and resampled for the Sentinel-2 application, employing the Spectral Angle Mapper (SAM) algorithm. Field validation and an unmanned aerial vehicle (UAV) survey confirmed surface placer occurrences and the SAM\u2019s results. Santa Marta Beach exhibited significant placer anomalies (up to 30% HM), correlating with low SAM values (minimum value\u20130.10), indicating high spectral similarity. The SAM-derived anomaly patches aligned with the field observations, demonstrating Sentinel-2\u2019s potential for placer deposit mapping. This work highlights the application of Sentinel-2 in the exploration of placer deposits and the use of a specific spectral range of these deposits in coastal environments. These tools are non-invasive, more environmentally friendly, and sustainable, and can be extrapolated to other regions of the world with similar characteristics.<\/jats:p>","DOI":"10.3390\/rs17111824","type":"journal-article","created":{"date-parts":[[2025,5,23]],"date-time":"2025-05-23T09:58:09Z","timestamp":1747994289000},"page":"1824","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Spectral Angle Mapper Application Using Sentinel-2 in Coastal Placer Deposits in Vigo Estuary, Northwest Spain"],"prefix":"10.3390","volume":"17","author":[{"given":"Wai L.","family":"Ng-Cutipa","sequence":"first","affiliation":[{"name":"Marine Geology Resources and Extreme Environments, Geological Survey of Spain (IGME-CSIC), Calle R\u00edos Rosas 23, 28003 Madrid, Spain"},{"name":"Departamento de Mineralog\u00eda y Petrolog\u00eda, Facultad de Ciencias Geol\u00f3gicas, Universidad Complutense de Madrid, Calle Jose Antonio Novais 12, Ciudad Universitaria, 28040 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8620-6506","authenticated-orcid":false,"given":"Ana","family":"Lobato","sequence":"additional","affiliation":[{"name":"Marine Geology Resources and Extreme Environments, Geological Survey of Spain (IGME-CSIC), Calle R\u00edos Rosas 23, 28003 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6311-1950","authenticated-orcid":false,"given":"Francisco Javier","family":"Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Marine Geology Resources and Extreme Environments, Geological Survey of Spain (IGME-CSIC), Calle R\u00edos Rosas 23, 28003 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-1180-2519","authenticated-orcid":false,"given":"Georgios P.","family":"Georgalas","sequence":"additional","affiliation":[{"name":"Hellenic Survey of Geology & Mineral Exploration (HSGME), Spirou Loui 1, 13677 Athens, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3440-4316","authenticated-orcid":false,"given":"Irene","family":"Zananiri","sequence":"additional","affiliation":[{"name":"Hellenic Survey of Geology & Mineral Exploration (HSGME), Spirou Loui 1, 13677 Athens, Greece"}]},{"given":"Morgana","family":"Carvalho","sequence":"additional","affiliation":[{"name":"Institute of Earth Sciences, Faculty of Sciences, University of Porto, Rua Campo Alegre s\/n, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8265-3897","authenticated-orcid":false,"given":"Joana","family":"Cardoso-Fernandes","sequence":"additional","affiliation":[{"name":"Institute of Earth Sciences, Faculty of Sciences, University of Porto, Rua Campo Alegre s\/n, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5451-2288","authenticated-orcid":false,"given":"Luis","family":"Somoza","sequence":"additional","affiliation":[{"name":"Marine Geology Resources and Extreme Environments, Geological Survey of Spain (IGME-CSIC), Calle R\u00edos Rosas 23, 28003 Madrid, Spain"}]},{"given":"Rub\u00e9n","family":"Pi\u00f1a","sequence":"additional","affiliation":[{"name":"Departamento de Mineralog\u00eda y Petrolog\u00eda, Facultad de Ciencias Geol\u00f3gicas, Universidad Complutense de Madrid, Calle Jose Antonio Novais 12, Ciudad Universitaria, 28040 Madrid, Spain"}]},{"given":"Rosario","family":"Lunar","sequence":"additional","affiliation":[{"name":"Departamento de Mineralog\u00eda y Petrolog\u00eda, Facultad de Ciencias Geol\u00f3gicas, Universidad Complutense de Madrid, Calle Jose Antonio Novais 12, Ciudad Universitaria, 28040 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8043-6431","authenticated-orcid":false,"given":"Ana Claudia","family":"Teodoro","sequence":"additional","affiliation":[{"name":"Institute of Earth Sciences, Faculty of Sciences, University of Porto, Rua Campo Alegre s\/n, 4169-007 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"618","DOI":"10.1016\/j.oregeorev.2007.03.006","article-title":"The Changing Vision of Marine Minerals","volume":"33","author":"Rona","year":"2008","journal-title":"Ore Geol. 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