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Improving the analysis of biogeochemical patterns associated with internal waves in the strait of Gibraltar using remote sensing images / Gabriel Navarro in Estuarine, Coastal and Shelf Science, vol 204 (May 2018)  

Public [article]  inEstuarine, Coastal and Shelf Science > vol 204 (May 2018) . - pp 1 - 13 Titre : Improving the analysis of biogeochemical patterns associated with internal waves in the strait of Gibraltar using remote sensing images Type de document : Article/Communication Auteurs : Gabriel Navarro, Auteur ; Jorge Vicent, Auteur ; Isabel Caballero, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 1 - 13 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] Gibraltar (Royaume-Uni) [Termes IGN] image Sentinel-MSI [Termes IGN] Méditerranée, mer [Termes IGN] vague Résumé : (auteur) High Amplitude Internal Waves (HAIWs) are physical processes observed in the Strait of Gibraltar (the narrow channel between the Atlantic Ocean and the Mediterranean Sea). These internal waves are generated over the Camarinal Sill (western side of the strait) during the tidal outflow (toward the Atlantic Ocean) when critical hydraulic conditions are established. HAIWs remain over the sill for up to 4 h until the outflow slackens, being then released (mostly) towards the Mediterranean Sea. These have been previously observed using Synthetic Aperture Radar (SAR), which captures variations in surface water roughness. However, in this work we use high resolution optical remote sensing, with the aim of examining the influence of HAIWs on biogeochemical processes. We used hyperspectral images from the Hyperspectral Imager for the Coastal Ocean (HICO) and high spatial resolution (10 m) images from the MultiSpectral Instrument (MSI) onboard the Sentinel-2A satellite. This work represents the first attempt to examine the relation between internal wave generation and the water constituents of the Camarinal Sill using hyperspectral and high spatial resolution remote sensing images. This enhanced spatial and spectral resolution revealed the detailed biogeochemical patterns associated with the internal waves and suggests local enhancements of productivity associated with internal waves trains. Numéro de notice : A2018-146 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.ecss.2018.02.009 Date de publication en ligne : 10/02/2018 En ligne : https://doi.org/10.1016/j.ecss.2018.02.009 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89755 [article]

Evaluation of forest fire on Madeira Island using Sentinel-2A MSI imagery / Gabriel Navarro in International journal of applied Earth observation and geoinformation, vol 58 (June 2017)  

Public [article]  inInternational journal of applied Earth observation and geoinformation > vol 58 (June 2017) . - pp 97 - 106 Titre : Evaluation of forest fire on Madeira Island using Sentinel-2A MSI imagery Type de document : Article/Communication Auteurs : Gabriel Navarro, Auteur ; Isabel Caballero, Auteur ; Gustavo Silva, Auteur ; Pedro-Cecilio Parra, Auteur ; Águeda Vázquez, Auteur ; Rui Caldeira, Auteur Année de publication : 2017 Article en page(s) : pp 97 - 106 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] correction atmosphérique [Termes IGN] image Sentinel-MSI [Termes IGN] incendie de forêt [Termes IGN] indice de végétation [Termes IGN] Madère, île de [Termes IGN] signature spectrale [Termes IGN] surveillance de la végétation Résumé : (auteur) A forest fire started on August 8th, 2016 in several places on Madeira Island causing damage and casualties. As of August 10th the local media had reported the death of three people, over 200 people injured, over 950 habitants evacuated, and 50 houses damaged. This study presents the preliminary results of the assessment of several spectral indices to evaluate the burn severity of Madeira fires during August 2016. These spectral indices were calculated using the new European satellite Sentinel-2A launched in June 2015. The study confirmed the advantages of several spectral indices such as Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Normalized Burn Ratio (NBR) and Normalized Difference Vegetation Index (NDVIreXn) using red-edge spectral bands to assess the post-fire conditions. Results showed high correlation between NDVI, GNDVI, NBR and NDVIre1n spectral indices and the analysis performed by Copernicus Emergency Management Service (EMSR175), considered as the reference truth. Regarding the red-edge spectral indices, the NDVIre1n (using band B5, 705 nm) presented better results compared with B6 (740 nm) and B7 (783 nm) bands. These preliminary results allow us to assume that Sentinel-2 will be a valuable tool for post-fire monitoring. In the future, the two twin Sentinel-2 satellites will offer global coverage of the Madeira Archipelago every five days, therefore allowing the simultaneous study of the evolution of the burnt area and reforestation information with high spatial (up to 10 m) and temporal resolution (5 days). Numéro de notice : A2017-366 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.jag.2017.02.003 En ligne : https://doi.org/10.1016/j.jag.2017.02.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85794 [article]