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Automatic detection of inland water bodies along altimetry tracks for estimating surface water storage variations in the Congo basin / Frédéric Frappart in Remote sensing, vol 13 n° 19 (October-1 2021)  

Public [article]  inRemote sensing > vol 13 n° 19 (October-1 2021) . - n° 3804 Titre : Automatic detection of inland water bodies along altimetry tracks for estimating surface water storage variations in the Congo basin Type de document : Article/Communication Auteurs : Frédéric Frappart, Auteur ; Pierre Zeiger, Auteur ; Julie Betbeder, Auteur ; Valéry Gond, Auteur ; Régis Bellot , Auteur ; Nicolas Baghdadi, Auteur ; Fabien Blarel, Auteur ; José Darrozes, Auteur ; Luc Bourrel, Auteur ; Frédérique Seyler, Auteur Année de publication : 2021 Projets : TOSCA / Article en page(s) : n° 3804 Note générale : bibliographie This research was funded by CNES TOSCA grants number CASCHMIR and SWHYM. Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] classification par nuées dynamiques [Termes IGN] Congo (bassin) [Termes IGN] détection automatique [Termes IGN] données altimétriques [Termes IGN] eau de surface [Termes IGN] estimation statistique [Termes IGN] image Envisat-ASAR [Termes IGN] image Jason-AMR [Termes IGN] niveau de l'eau [Termes IGN] série temporelle [Termes IGN] stockage [Termes IGN] volume d'eau [Termes IGN] zone humide Résumé : (auteur) Surface water storage in floodplains and wetlands is poorly known from regional to global scales, in spite of its importance in the hydrological and the carbon balances, as the wet areas are an important water compartment which delays water transfer, modifies the sediment transport through sedimentation and erosion processes, and are a source for greenhouse gases. Remote sensing is a powerful tool for monitoring temporal variations in both the extent, level, and volume, of water using the synergy between satellite images and radar altimetry. Estimating water levels over flooded area using radar altimetry observation is difficult. In this study, an unsupervised classification approach is applied on the radar altimetry backscattering coefficients to discriminate between flooded and non-flooded areas in the Cuvette Centrale of Congo. Good detection of water (open water, permanent and seasonal inundation) is above 0.9 using radar altimetry backscattering from ENVISAT and Jason-2. Based on these results, the time series of water levels were automatically produced. They exhibit temporal variations in good agreement with the hydrological regime of the Cuvette Centrale. Comparisons against a manually generated time series of water levels from the same missions at the same locations show a very good agreement between the two processes (i.e., RMSE ≤ 0.25 m in more than 80%/90% of the cases and R ≥ 0.95 in more than 95%/75% of the cases for ENVISAT and Jason-2, respectively). The use of the time series of water levels over rivers and wetlands improves the spatial pattern of the annual amplitude of water storage in the Cuvette Centrale. It also leads to a decrease by a factor of four for the surface water estimates in this area, compared with a case where only time series over rivers are considered. Numéro de notice : A2021-935 Affiliation des auteurs : IGN+Ext (2020- ) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs13193804 Date de publication en ligne : 23/09/2021 En ligne : https://doi.org/10.3390/rs13193804 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99542 [article]

Reclaimed-airport surface-deformation monitoring by improved permanent-scatterer interferometric synthetic-aperture radar: a case study of Shenzhen Bao'an international airport, China / Lu Miao in Photogrammetric Engineering & Remote Sensing, PERS, vol 87 n° 2 (February 2021)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 87 n° 2 (February 2021) . - pp 105-116 Titre : Reclaimed-airport surface-deformation monitoring by improved permanent-scatterer interferometric synthetic-aperture radar: a case study of Shenzhen Bao'an international airport, China Type de document : Article/Communication Auteurs : Lu Miao, Auteur ; Kailiang Deng, Auteur ; Guangcai Feng, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 105-116 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] aéroport [Termes IGN] coin réflecteur [Termes IGN] déformation d'édifice [Termes IGN] déformation de surface [Termes IGN] données spatiotemporelles [Termes IGN] image Envisat-ASAR [Termes IGN] image Sentinel-SAR [Termes IGN] interféromètrie par radar à antenne synthétique [Termes IGN] piste d'aéroport [Termes IGN] Shenzhen [Termes IGN] surveillance d'ouvrage [Termes IGN] surveillance géologique Résumé : (Auteur) Reclaimed airports usually have fragile geological structures and are susceptible to the uneven ground settlements caused by filling-material consolidation, underground construction, and dynamic loading from takeoff and landing of aircrafts. Therefore, deformation monitoring is of great significance to the safe operation of reclaimed airports. This study adopts an improved permanent-scatterer interferometric synthetic-aperture radar strategy to map the spatiotemporal deformation of Shenzhen Bao'an International Airport in China using ascending and descending Envisat/ASAR data acquired from 2007 to 2010 and Sentinel-1 data from 2015 to 2019. The results show that uneven settlements of the airport concentrate in the new reclaimed land. Then we explore the settlement characteristics of each functional area. Furthermore, we separate out the dynamic-load settlement of runway No. 2 and confirm the settlements caused by dynamic load. This study provides new ideas for studying deformation in similar fields, and technical references for the future construction of Shenzhen Airport. Numéro de notice : A2021-098 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.87.2.105 Date de publication en ligne : 01/02/2021 En ligne : https://doi.org/10.14358/PERS.87.2.105 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97042 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
105-2021021	SL	Revue	Centre de documentation	Revues en salle	Disponible

Assessment of chlorophyll-a concentration from Sentinel-3 satellite images at the Mediterranean Sea using CMEMS open source in situ data / Ioannis Moutzouris-Sidiris in Open geosciences, vol 13 n° 1 (January 2021)  

Public [article]  inOpen geosciences > vol 13 n° 1 (January 2021) . - pp 85 - 97 Titre : Assessment of chlorophyll-a concentration from Sentinel-3 satellite images at the Mediterranean Sea using CMEMS open source in situ data Type de document : Article/Communication Auteurs : Ioannis Moutzouris-Sidiris, Auteur ; Konstantinos Topouzelis, Auteur Année de publication : 2021 Article en page(s) : pp 85 - 97 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse comparative [Termes IGN] chlorophylle [Termes IGN] classification par réseau neuronal [Termes IGN] couleur de l'océan [Termes IGN] image Envisat-MERIS [Termes IGN] image Sentinel-3 [Termes IGN] image Sentinel-OLCI [Termes IGN] Méditerranée, mer Résumé : (auteur) The objective of this study is to evaluate the efficiency of two well-known algorithms (Ocean Colour 4 for MERIS [OC4Me] and neural net [NN]) used in the calculation of chlorophyll-a (Chl-a) from the Sentinel-3 Ocean and Land Colour Instrument (OLCI) compared to in situ measurements covering the Mediterranean Sea. In situ data set, obtained from the Copernicus Marine Environmental Monitoring Service (CMEMS) and more specifically from the data set with the title INSITU_MED_NRT_OBSERVATIONS_013_035, and Chl-a values at different depths were extracted. The concentration of Chl-a at a penetration depth was calculated. Then, water was classified into two categories, Case-1 and Case-2. For Case-2 waters, the OC4Me presents a moderate correlation with the in situ data for a time window of 0–2 h. In contrast with the NN algorithm, where very weak correlations were calculated, lower values of the statistical index of Bias for Case-1 waters were calculated for the OC4Me algorithm. Higher values of Pearson correlation were calculated (r > 0.5) for OC4Me algorithm than NN. OC4Me performed better than NN. Numéro de notice : A2021-487 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1515/geo-2020-0204 Date de publication en ligne : 29/01/2021 En ligne : https://doi.org/10.1515/geo-2020-0204 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97776 [article]

Characterization of mass variations in Antarctica in response to climatic fluctuations from space-based gravimetry and radar altimetry data / Athul Kaitheri (2021)  

Public Titre : Characterization of mass variations in Antarctica in response to climatic fluctuations from space-based gravimetry and radar altimetry data Titre original : Caractérisation des variations de masse en Antarctique en réponse aux fluctuations climatiques à partir des données de gravimétrie spatiale et d’altimétrie radar Type de document : Thèse/HDR Auteurs : Athul Kaitheri, Auteur ; Anthony Mémin, Directeur de thèse ; Frédérique Rémy, Directeur de thèse Editeur : Nice : Université Côte d'Azur Année de publication : 2021 Importance : 138 p. Format : 21 x 30 cm Note générale : Bibliographie Thèse présentée en vue de l’obtention du grade de docteur de l'Université de Côte d'Azur, Spécialité Sciences de la Planète et de l'Univers Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] altimétrie satellitaire par radar [Termes IGN] analyse comparative [Termes IGN] Antarctique [Termes IGN] calotte glaciaire [Termes IGN] changement climatique [Termes IGN] données altimétriques [Termes IGN] données GRACE [Termes IGN] image Envisat [Termes IGN] levé gravimétrique [Termes IGN] masse [Termes IGN] oscillation [Termes IGN] régression Index. décimale : THESE Thèses et HDR Résumé : (Auteur) Quantifying the mass balance of the Antarctic Ice Sheet (AIS), and the resulting sea level rise, requires an understanding of inter-annual variability and associated causal mechanisms. This has become more complex and challenging in the backdrop of global climate change. Very few studies have been exploring the influence of climate anomalies on the AIS and only a vague estimate of its impact is available. Usually changes to the ice sheet are quantified using observations from space-borne altimetry and gravimetry missions. In this study, we use data from Envisat (2002 to 2010) and Gravity Recovery and Climate Experiment (GRACE) (2002 to 2016) missions to estimate monthly elevation changes and mass changes, respectively. Similar estimates of the changes are made using weather variables (surface mass balance (SMB) and temperature) from a regional climate model (RACMO2.3p2) as inputs to a firn compaction (FC) model. Using the firn compaction model we were able to model the transformation of snow into glacial ice and hence estimate changes in the elevation of the ice sheet using climate parameters. Elevation changes estimated from different techniques are in good agreement with each other across the AIS especially in West Antarctica, Antarctic Peninsula, and along the coasts of East Antarctica. Inter-annual height change patterns are then extracted using for the first time an empirical mode decomposition followed by a reconstruction of modes. These signal on applying least square method revealed a sub-4-year periodic signal in the all the three distinct height change patterns. This was indicative of the influence of the El Niño Southern Oscillation (ENSO), a climate anomaly that alters, among other parameters, moisture transport, sea surface temperature, precipitation, in and around the AIS at similar frequency by alternating between warm and cold conditions. But there existed altering periodic behavior among inter annual height change patterns in the Antarctic Pacific (AP) sector which was found possibly by the influence of multiple climate drivers, like the Amundsen Sea Low (ASL) and the Southern Annular Mode (SAM). A combined analysis of the three distinct estimates using a PCA (principal component analysis) along the coast revealed similar findings. Height change anomaly also appears to traverse eastwards from Coats Land to Pine Island Glacier (PIG) regions passing through Dronning Maud Land (DML) and Wilkes Land (WL) in 6 to 8 years. This is indicative of climate anomaly traversal due to the Antarctic Circumpolar Wave (ACW) which propagates anomalies through the Southern Ocean in 8 to 10 years. Altogether, inter-annual variability in the SMB of the AIS is found to be modulated by multiple competing climate anomalies. Note de contenu : 1. Introduction 1.1 Climate change scenario 1.2 Antarctica 1.3 Thesis overview 2. Height changes from satellite observations 2.1 Observations 2.2 Satellite gravimetry 2.3 Satellite altimetry 3. Height changes from modelling 3.1 Climate Model 3.2 Height changes from RACMO2.3p2 outputs 3.3 Firn densification model 4. Inter-annual variability 4.1 Comparison between height changes 4.2 Extraction of inter annual signals 4.3 Characterizing inter-annual signals 4.4 Principal component analysis 5. Influence of climate anomalies 5.1 El Ni˜no Southern Oscillation 5.2 Southern Annular Mode 5.3 Amundsen Sea Low 5.4 Antarctic Circumpolar Wave 6. General conclusions 6.1 Conclusions 6.2 Future perspectives Numéro de notice : 26825 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Thèse française Note de thèse : Thèse de doctorat : Sciences de la Planète et de l'Univers : Côte d'Azur : 2021 Organisme de stage : Géoazur nature-HAL : Thèse DOI : sans Date de publication en ligne : 19/04/2022 En ligne : https://tel.hal.science/tel-03644306/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100655

Illuminating the spatio-temporal evolution of the 2008–2009 Qaidam earthquake sequence with the joint use of Insar time series and teleseismic data / Simon Daout in Remote sensing, vol 12 n° 17 (September-1 2020)  

Public [article]  inRemote sensing > vol 12 n° 17 (September-1 2020) . - 23 p. Titre : Illuminating the spatio-temporal evolution of the 2008–2009 Qaidam earthquake sequence with the joint use of Insar time series and teleseismic data Type de document : Article/Communication Auteurs : Simon Daout, Auteur ; Andreas Steinberg, Auteur ; Marius Paul Isken, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : 23 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] analyse spatio-temporelle [Termes IGN] données géodésiques [Termes IGN] faille géologique [Termes IGN] image Envisat [Termes IGN] image radar moirée [Termes IGN] inférence [Termes IGN] interféromètrie par radar à antenne synthétique [Termes IGN] séisme [Termes IGN] série temporelle [Termes IGN] sismologie [Termes IGN] Tsinghai (Chine) Résumé : (auteur) Inferring the geometry and evolution of an earthquake sequence is crucial to understand how fault systems are segmented and interact. However, structural geological models are often poorly constrained in remote areas and fault inference is an ill-posed problem with a reliability that depends on many factors. Here, we investigate the geometry of the Mw 6.3 2008 and 2009 Qaidam earthquakes, in northeast Tibet, by combining InSAR time series and teleseismic data. We conduct a multi-array back-projection analysis from broadband teleseismic data and process three overlapping Envisat tracks covering the two earthquakes to extract the spatio-temporal evolution of seismic ruptures. We then integrate both geodetic and seismological data into a self-consistent kinematic model of the earthquake sequence. Our results constrain the depth and along-strike segmentation of the thrust-faulting sequence. The 2008 earthquake ruptured a ∼32° north-dipping fault that roots under the Olongbulak pop-up structure at ∼12 km depth and fault slip evolved post-seismically in a downdip direction. The 2009 earthquake ruptured three south-dipping high-angle thrusts and propagated from ∼9 km depth to the surface and bilaterally along the south-dipping segmented 55–75° high-angle faults of the Olonbulak pop-up structure that displace basin deformed sedimentary sequences above Paleozoic bedrock. Our analysis reveals that the inclusion of the post-seismic afterslip into modelling is beneficial in the determination of fault geometry, while teleseismic back-projection appears to be a robust tool for identifying rupture segmentation for moderate-sized earthquakes. These findings support the hypothesis that the Qilian Shan is expanding southward along a low-angle décollement that partitions the oblique convergence along multiple flower and pop-up structures. Numéro de notice : A2020-599 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.3390/rs12172850 Date de publication en ligne : 02/09/2020 En ligne : https://doi.org/10.3390/rs12172850 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95947 [article]

Conterminous United States land cover change patterns 2001–2016 from the 2016 National Land Cover Database / Collin Homer in ISPRS Journal of photogrammetry and remote sensing, vol 162 (April 2020)  

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Le sol s'affaisse, l'eau monte [Delta du Gange-Brahmapoutre-Meghna] / Marielle Mayo in Géomètre, n° 2179 (avril 2020)

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Estuaries and coastal zones / Jiayi Pan (2020)  

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Exploring the synergy between Landsat and ASAR towards improving thematic mapping accuracy of optical EO data / Alexander Cass in Applied geomatics, vol 11 n° 3 (September 2019)  

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Analyse de la déformation récente dans le Grand Tunis par interférométrie radar SAR / Anis Chaabani (2019)  

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Analysis and modelling of remote sensing reflectance during anoxic crisis in the Thau lagoon using satellite images / Manchun Lei (2019)  

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Global observations of ocean surface winds and waves using spaceborne synthetic aperture radar measurements / Huimin Li (2019)  

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Satellite altimetry for earth sciences / Frédéric Frappart (2019)  

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Soil moisture estimation in Ferlo region (Senegal) using radar (ENVISAT/ASAR) and optical (SPOT/VEGETATION) data / Gayane Faye in The Egyptian Journal of Remote Sensing and Space Science, Vol. 21 suppl.1 (juillet 2018)  

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Contribution actuelle de la calotte Antarctique à la variation du niveau marin / Clémence Chupin (2018) 

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