{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T20:59:44Z","timestamp":1775509184430,"version":"3.50.1"},"reference-count":47,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2024,12,4]],"date-time":"2024-12-04T00:00:00Z","timestamp":1733270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministry of Science, Innovation and Universities\u2014National Research Agency","award":["PID2021-124272OB-C22"],"award-info":[{"award-number":["PID2021-124272OB-C22"]}]},{"name":"Spanish Ministry of Science, Innovation and Universities\u2014National Research Agency","award":["TED2021-130321B-I00"],"award-info":[{"award-number":["TED2021-130321B-I00"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Coastal zones, particularly sandy beaches, are highly dynamic environments subject to a variety of natural and anthropogenic forcings. Instantaneous shoreline is a widely used indicator of beach changes in image-based applications, and it can display undulations at different spatial and temporal scales. Megacusps, periodic seaward and landward shoreline perturbations, are an example of such undulations that can significantly modify beach width and impact its usability. Traditionally, the study of these phenomena relied on video monitoring systems, which provide high-frequency imagery but limited spatial coverage. Instead, this study explored the potential of employing multispectral satellite-derived shorelines, specifically from Sentinel-2 (S2) and PlanetScope (PLN) platforms, for characterizing and monitoring megacusps\u2019 formation and their dynamics over time. First, a tool was developed and validated to guarantee accurate shoreline detection, based on a combination of spectral indices, along with both thresholding and unsupervised clustering techniques. Validation of this shoreline detection phase was performed on three micro-tidal Mediterranean beaches, comparing with high-resolution orthomosaics and in-situ GNSS data, obtaining a good subpixel accuracy (with a mean absolute deviation of 1.5\u20135.5 m depending on the satellite type). Second, a tool for megacusp characterization was implemented and subsequent validation with reference data proved that satellite-derived shorelines could be used to robustly and accurately describe megacusps. The methodology could not only capture their amplitude and wavelength (of the order of 10 and 100 m, respectively) but also monitor their weekly\u2013daily evolution using different potential metrics, thanks to combining S2 and PLN imagery. Our findings demonstrate that multispectral satellite imagery provides a viable and scalable solution for monitoring shoreline megacusp undulations, enhancing our understanding and offering an interesting option for coastal management.<\/jats:p>","DOI":"10.3390\/rs16234553","type":"journal-article","created":{"date-parts":[[2024,12,4]],"date-time":"2024-12-04T10:07:10Z","timestamp":1733306830000},"page":"4553","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Development of Methods for Satellite Shoreline Detection and Monitoring of Megacusp Undulations"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0625-3573","authenticated-orcid":false,"given":"Riccardo","family":"Angelini","sequence":"first","affiliation":[{"name":"Department of Civil and Environmental Engineering, University of Florence, via di Santa Marta 3, 50139 Florence, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7321-4825","authenticated-orcid":false,"given":"Eduard","family":"Angelats","sequence":"additional","affiliation":[{"name":"Geomatics Research Unit, Centre Tecnol\u00f2gic de Telecomunicacions de Catalunya (CTTC\/CERCA), Av. Carl Friedrich Gauss 7, 08860 Castelldefels, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8924-9029","authenticated-orcid":false,"given":"Guido","family":"Luzi","sequence":"additional","affiliation":[{"name":"Geomatics Research Unit, Centre Tecnol\u00f2gic de Telecomunicacions de Catalunya (CTTC\/CERCA), Av. Carl Friedrich Gauss 7, 08860 Castelldefels, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8028-2815","authenticated-orcid":false,"given":"Andrea","family":"Masiero","sequence":"additional","affiliation":[{"name":"Interdepartmental Research Center of Geomatics (CIRGEO), University of Padova, via dell\u2019Universit\u00e0 16, 35020 Legnaro, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6420-5975","authenticated-orcid":false,"given":"Gonzalo","family":"Simarro","sequence":"additional","affiliation":[{"name":"Department of Marine Geosciences, Institut de Ci\u00e8ncies del Mar, Passeig Mar\u00edtim de la Barceloneta 37-49, 08003 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4701-5982","authenticated-orcid":false,"given":"Francesca","family":"Ribas","sequence":"additional","affiliation":[{"name":"Physics Department, Universitat Polit\u00e8cnica de Catalunya, Carrer Jordi Girona 1-3, 08980 Barcelona, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Luijendijk, A.P., Hagenaars, G., Ranasinghe, R., Baart, F., Donchyts, G., and Aarninkhof, S. 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