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ScanSAR-to-Stripmap mode interferometry processing using ENVISAT-ASAR Data / A.B. Ortiz in IEEE Transactions on geoscience and remote sensing, vol 45 n° 11 Tome 1 (November 2007)
[article]
Titre : ScanSAR-to-Stripmap mode interferometry processing using ENVISAT-ASAR Data Type de document : Article/Communication Auteurs : A.B. Ortiz, Auteur ; H. Zebker, Auteur Année de publication : 2007 Article en page(s) : pp 3468 - 3480 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse diachronique
[Termes IGN] éruption volcanique
[Termes IGN] Hawaii (Etats-Unis)
[Termes IGN] image Envisat-ASAR
[Termes IGN] image radar moirée
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] séisme
[Termes IGN] transformation en ZRésumé : (Auteur) Interferometric synthetic aperture radar (InSAR) images of geophysical events such as preeruptive volcano deformation or interseismic strain accumulation are often limited by phase distortions from the superimposed atmospheric signature. Additionally, the approximate monthly repeat cycle of many radar satellites cannot accurately capture rapidly time-varying processes. The Scanning Synthetic Aperture Radar (ScanSAR) mode of the ENVISAT/ASAR instrument permits more frequent revisits of a given area, potentially overcoming both of these limitations. In particular, stripmap mode-to-ScanSAR images provide a denser time series of interferograms than is possible with conventional stripmap-to-stripmap mode InSAR. We present images of ENVISAT/ASAR data acquired over Hawaii in which data acquired roughly weekly in ScanSAR mode are combined with ENVISAT/ASAR conventional stripmap mode data to form interferograms at a much denser temporal spacing. The burst nature of ScanSAR data requires a new processing method to form the interferograms. We use traditional matched filtering for the range compression. For the azimuth processing, we compute the stripmap mode data on the ScanSAR sampling grid using a variation, consisting of different reference functions, of Lanari's modified SPECAN algorithm that is itself an adaptation of the chirp z -transform to readjust the azimuth pulse spacing. The resulting interferograms faithfully reflect the phase of conventional interferograms, but exhibit fewer looks and coarser resolution than those produced by fully stripmap mode data. For many problems, temporal density of the deformation observations is paramount, and the time series analysis and temporal averaging that were made possible using ScanSAR interferograms far out-weigh the loss in looks and resolution. Copyright IEEE Numéro de notice : A2007-504 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2007.895970 En ligne : https://doi.org/10.1109/TGRS.2007.895970 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28867
in IEEE Transactions on geoscience and remote sensing > vol 45 n° 11 Tome 1 (November 2007) . - pp 3468 - 3480[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-07111A RAB Revue Centre de documentation En réserve L003 Disponible Dual-frequency altimeter signal from Envisat on the Amery ice-shelf / Pascal Lacroix in Remote sensing of environment, vol 109 n° 3 (15 August 2007)
[article]
Titre : Dual-frequency altimeter signal from Envisat on the Amery ice-shelf Type de document : Article/Communication Auteurs : Pascal Lacroix, Auteur ; Benoit Legrésy, Auteur ; et al., Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 285 - 294 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] altimétrie par radar
[Termes IGN] Antarctique
[Termes IGN] bande S
[Termes IGN] calotte glaciaire
[Termes IGN] crevasse
[Termes IGN] écho radar
[Termes IGN] épaisseur de la glace
[Termes IGN] image Envisat-AATSR
[Termes IGN] réflectance de surface
[Termes IGN] réflexion spéculaire
[Termes IGN] traitement du signal
[Termes IGN] variation saisonnièreRésumé : (Auteur) In Antarctica, radar altimeter measurements are sensitive to dielectric and penetration properties of the sensed medium (snow) such that the spacecraft's altitude can be biased. Since 2002, relatively low frequency radar measurements over the Amery Ice Shelf, east Antarctica, have been acquired using the Envisat dual frequency altimeter at S (3.2 GHz) and Ku (13.6 GHz) bands, which penetrate a few meters into the firn. The altimeter signal is however modified in summer by the presence of snowfilled crevasses. Indeed, the specularity of the snow surfaces in summer makes the altimetric signal sensitive mostly to nadir echoes, that increases the ratio between the crevasse signal and the surrounding ice-shelf signal at nadir. Crevasses are distinguished by differences in backscattering behavior compared with the surrounding ice-shelf signal. Crevasses are characterized by a strong backscatter coefficient at Ku band and anomalies in the S band altitude estimation. These two characteristics make snowfilled crevasses detectable by the dual frequency altimeter of Envisat. We first retrieve the geometric properties of the crevasses using a hyperbolic shape function, created by strong crevasse backscatter in the Ku waveform measurements. From this retrieved crevasse signal and further waveform analysis, we assess the properties of the snow surface and its sub-surface. The crevasse, due to its small size compared to the altimeter footprint, is found to be an excellent target to study snow properties of the ice-shelf. The anomalies in the S band altitude measurements over crevasses can then be explained by the presence of a double echo in the S band waveforms. This echo is attributed to a reflection at the base of the snowbridge, where we see evidence of sub-surface echos in the individual altimeter waveforms. Based on this observation, a methodology is developed to estimate the thickness of the snowbridge. We calculate the penetration depths in the summer snow surface of the Amery at Ku band, that is found to be around 6 m. Copyright Elsevier Numéro de notice : A2007-312 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2007.01. En ligne : https://doi.org/10.1016/j.rse.2007.01.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28675
in Remote sensing of environment > vol 109 n° 3 (15 August 2007) . - pp 285 - 294[article]The 26 December 2004 tsunami measured by satellite altimetry / J. Gower in International Journal of Remote Sensing IJRS, vol 28 n° 13-14 (July 2007)
[article]
Titre : The 26 December 2004 tsunami measured by satellite altimetry Type de document : Article/Communication Auteurs : J. Gower, Auteur Année de publication : 2007 Article en page(s) : pp 2897 - 2913 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] altimétrie satellitaire par radar
[Termes IGN] Bengale, golfe du
[Termes IGN] données altimétriques
[Termes IGN] épicentre
[Termes IGN] image Envisat
[Termes IGN] Indien (océan)
[Termes IGN] Jason
[Termes IGN] océanographie spatiale
[Termes IGN] séisme
[Termes IGN] surface de la mer
[Termes IGN] TOPEX-Poseidon
[Termes IGN] tsunami
[Vedettes matières IGN] AltimétrieRésumé : (Auteur) The 26 December 2004 magnitude 9 earthquake off Sumatra provided the first examples of travelling tsunami waves in mid-ocean clearly detected by satellite altimetry. The earthquake was the largest since satellite altimetry started in the 1970s and gave peak-to-trough wave heights in mid-ocean of over a metre. The tsunami was detected by three of the four altimeters presently giving sea surface height information. Each detected the spreading front twice, as it moved south-westwards into the Indian Ocean and as it moved northwards into the Bay of Bengal. They also detected the disturbed region closer to the epicentre that expands with the slower velocities of higher-frequency waves. Although the plate rupture is estimated to extend over about 1300 km in a north/south direction, the satellite observations appear consistent with a smaller generation area towards the south of this rupture zone. Fronts observed in the Indian Ocean show a positive first crest. Those observed in the Bay of Bengal are of smaller amplitude and appear to show a first negative first crest (trough). The structure in the Indian Ocean front observed by Jason-1 suggests the possible presence of a shorter-wavelength negative component superimposed on the positive crest. Copyright Taylor & Francis Numéro de notice : A2007-335 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160601094484 En ligne : https://doi.org/10.1080/01431160601094484 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28698
in International Journal of Remote Sensing IJRS > vol 28 n° 13-14 (July 2007) . - pp 2897 - 2913[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-07081 RAB Revue Centre de documentation En réserve L003 Disponible GMES, Global Monitoring for Environment and Security: the second European flagship in space / V. Liebig in ESA bulletin, n° 130 (May 2007)
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Titre : GMES, Global Monitoring for Environment and Security: the second European flagship in space Type de document : Article/Communication Auteurs : V. Liebig, Auteur ; J. Aschbacher, Auteur ; S. Briggs, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 11 - 16 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Copernicus (programme européen)
[Termes IGN] image Envisat
[Termes IGN] image Sentinel
[Termes IGN] protection de l'environnement
[Termes IGN] risque environnementalRésumé : (Auteur) Society and politicians are demanding operational information services in order to manage our planet's environment, understand and mitigate the effects of climate change, and ensure civil security for Europe's citizens. GMES can respond to these challenges by providing accurate, up-to-date and globally available information on an operational basis to European, national, regional and local entities. Important decisions are expected in the next two years on the future of GMES, including finalisation of the funding scheme for developing the infrastructure, and progress in setting up its long-term governance and funding. ESA's responsibility is to provide the GMES satellites, which includes developing a dedicated space infrastructure and coordinating the space contributions from all the partners. Numéro de notice : A2007-274 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : http://www.esa.int/esapub/bulletin/bulletin130/bul130a_liebig.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28637
in ESA bulletin > n° 130 (May 2007) . - pp 11 - 16[article]Atmospheric correction algorithm for MERIS above case-2 waters / Th. Schroeder in International Journal of Remote Sensing IJRS, vol 28 n°7-8 (April 2007)
[article]
Titre : Atmospheric correction algorithm for MERIS above case-2 waters Type de document : Article/Communication Auteurs : Th. Schroeder, Auteur ; I. Behnert, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 1469 - 1486 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] aérosol
[Termes IGN] classification par réseau neuronal
[Termes IGN] correction atmosphérique
[Termes IGN] image Envisat-MERIS
[Termes IGN] modèle de transfert radiatif
[Termes IGN] réflectanceRésumé : (Auteur) The development and validation of an atmospheric correction algorithm designed for the Medium Resolution Imaging Spectrometer (MERIS) with special emphasis on case-2 waters is described. The algorithm is based on inverse modelling of radiative transfer (RT) calculations using artificial neural network (ANN) techniques. The presented correction scheme is implemented as a direct inversion of spectral top-of-atmosphere (TOA) radiances into spectral remote sensing reflectances at the bottom-of-atmosphere (BOA), with additional output of the aerosol optical thickness (AOT) at four wavelengths for validation purposes. The inversion algorithm was applied to 13 MERIS Level 1b data tracks of 2002-2003, covering the optically complex waters of the North and Baltic Sea region. A validation of the retrieved AOTs was performed with coincident in situ automatic sun-sky scanning radiometer measurements of the Aerosol Robotic Network (AERONET) from Helgoland Island located in the German Bight. The accuracy of the derived reflectances was validated with concurrent ship-borne reflectance measurements of the SIMBADA hand-held field radiometer. Compared to the MERIS Level2 standard reflectance product generated by the processor versions 3.55, 4.06 and 6.3, the results of the proposed algorithm show a significant improvement in accuracy, especially in the blue part of the spectrum, where the MERIS Level 2 reflectances result in errors up to 122% compared to only 19% with the proposed algorithm. The overall mean errors within the spectral range of 412.5-708.75 nm are calculated to be 46.2% and 18.9% for the MERIS Level2 product and the presented algorithm, respectively. Copyright Taylor & Francis Numéro de notice : A2007-176 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160600962574 En ligne : https://doi.org/10.1080/01431160600962574 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28539
in International Journal of Remote Sensing IJRS > vol 28 n°7-8 (April 2007) . - pp 1469 - 1486[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-07041 RAB Revue Centre de documentation En réserve L003 Disponible Tidal analysis experiments with sun-synchronous satellite altimeter data / R.D. Ray in Journal of geodesy, vol 81 n° 4 (April 2007)PermalinkMERIS-FR potential for land use-land cover mapping / S. Garcia-Gigorro in International Journal of Remote Sensing IJRS, vol 28 n°5-6 (March 2007)PermalinkOil spill detection in Radarsat and Envisat SAR images / A.H. Solberg in IEEE Transactions on geoscience and remote sensing, vol 45 n° 3 (March 2007)PermalinkPotentiel des radars satellitaires embarqués sur Envisat et ERS pour le suivi et la cartographie de la dynamique côtière au large de Kourou (Guyane française) / J. Kouame in Photo interprétation, vol 43 n° 1 (Mars 2007)PermalinkStudy of rain events over the South China Sea by synergistic use of multi-sensor satellite and ground-based meteorological data / W. Alpers in Photogrammetric Engineering & Remote Sensing, PERS, vol 73 n° 3 (March 2007)PermalinkRegional products for the Baltic Sea using MERIS data / H. Krawczyk in International Journal of Remote Sensing IJRS, vol 28 n°3-4 (February 2007)Permalinkvol 28 n°3-4 - February 2007 - Special issue : MERIS (Medium Rresolution Imaging Spectrometer (Bulletin de International Journal of Remote Sensing IJRS) / Remote sensing and photogrammetry societyPermalinkValidation of MERIS Level-2 products in the Baltic Sea, the Namibian coastal area and the Atlantic Ocean / T. Ohde in International Journal of Remote Sensing IJRS, vol 28 n°3-4 (February 2007)PermalinkDetection of forest changes over French Guiana using ERS-1 and ASAR imagery / Yrjö Rauste (2007)PermalinkPermalink