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On the SAR backscatter of burned forests: a model-based study in C-Band, over burned pine canopies full text / Vasileios kalogirou in IEEE Transactions on geoscience and remote sensing, vol 52 n° 10 tome 1 (October 2014)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 52 n° 10 tome 1 (October 2014) . - pp 6205 - 6215 Titre : On the SAR backscatter of burned forests: a model-based study in C-Band, over burned pine canopies full text Type de document : Article/Communication Auteurs : Vasileios kalogirou, Auteur ; P. Ferrazzoli, Auteur ; Andrea Della Vecchia, Auteur ; Michael Foumelis, Auteur Année de publication : 2014 Article en page(s) : pp 6205 - 6215 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] forêt [Termes IGN] Grèce [Termes IGN] image C-SAR [Termes IGN] impact sur l'environnement [Termes IGN] incendie de forêt [Termes IGN] modèle de transfert radiatif [Termes IGN] rétrodiffusion Résumé : (Auteur) A discrete scattering model, based on the radiative-transfer theory, is used to simulate the backscattering of burned pine canopies at C-band. The model is first parameterized either with direct field measurements on a selected burned area in Greece or with proper estimations of the required variables, for which direct measurements were not possible. The simulated backscatter at VV polarization was compared against European Remote Sensing 2 (ERS-2) observations. The comparison was based on the observed backscattering of nine burned plots, during four different postfire acquisitions (n=36). In general, the model provides satisfying estimations of the backscattering with a root-mean-square error of 1.01 dB. The copolar signal for both HH and VV showed a mild decrease with increasing fire impacts and was considerably affected by the incidence angle. From the experiments performed in the simulated environment, it is concluded that the SAR copolar (C-band) backscatter varies with respect to certain fire impact levels. Other important acquisition- or stand-dependent variables (such as incidence angle and snag age) were also found to impact the relationship between backscatter and fire impacts. Finally, the backscattering variability on increasing volumetric soil moisture (VSM) and snag moisture was examined. The increase of VSM from 20% to 30% amplified the signal in both copolarized bands by 1.2-1.5 dB. This amplification was more apparent on VV polarization than in HH polarization. Instead, the HH signal proved to be more sensitive on the increase of snag moisture, which was tested under a stable dry soil. Numéro de notice : A2014-480 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2013.2295594 En ligne : https://doi.org/10.1109/TGRS.2013.2295594 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74061 [article]

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Model investigation about the potential of C-band SAR in herbaceous wetlands flood monitoring / F. Grings in International Journal of Remote Sensing IJRS, vol 29 n° 17-18 (September 2008)  

Public [article]  inInternational Journal of Remote Sensing IJRS > vol 29 n° 17-18 (September 2008) . - pp 5361 - 5372 Titre : Model investigation about the potential of C-band SAR in herbaceous wetlands flood monitoring Type de document : Article/Communication Auteurs : F. Grings, Auteur ; P. Ferrazzoli, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 5361 - 5372 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] bande C [Termes IGN] delta [Termes IGN] image Envisat-ASAR [Termes IGN] image radar [Termes IGN] marais [Termes IGN] Parana (Brésil) [Termes IGN] polarimétrie radar [Termes IGN] surveillance de la végétation Résumé : (Auteur) Wetlands are areas where the presence of water at or near the soil surface drives the natural system. Imaging radars (SARs) have distinct characteristics which make them of significant value for monitoring and mapping wetland inundation dynamics. The presence or absence of water (which has a much higher dielectric constant than dry or wet soil) in wetlands may significantly alter the signal detected from these areas depending on the dominant vegetation type, density, and height. The objective of this paper is to present our current research efforts to explain and correctly simulate the radar response of wetland vegetation/inundation mixtures, and use simulations as an aid for retrieval applications. The radar response of junco marshes under different flood conditions and vegetation stages is analysed using a set of 13 multipolarization ENVISAT ASAR scenes acquired over the Paraná River Delta marshes during the period 2003-2005. The main aspect of the approach followed is the simulation of SAR wave interactions with vegetation and water, using an adapted and improved version of the EM model developed at Tor Vergata University. The results obtained indicate that with the refined EM model, it is possible to represent with a good accuracy VV and HH SAR responses of junco marshes for a variety of environmental conditions. Further work and data are needed to explain measured HV backscattering. The general agreement obtained between simulations and observations permitted the development of a simple retrieval scheme, and estimates of water level below the canopy were obtained for different environmental conditions. RMS errors of forward simulations and retrievals are reported and discussed. Copyright Taylor & Francis Numéro de notice : A2008-532 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160802036409 En ligne : https://doi.org/10.1080/01431160802036409 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29602 [article]

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Simulating L-band emission of forests in view of future satellite applications / P. Ferrazzoli in IEEE Transactions on geoscience and remote sensing, vol 40 n° 12 (December 2002)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 40 n° 12 (December 2002) . - pp 2700 - 2708 Titre : Simulating L-band emission of forests in view of future satellite applications Type de document : Article/Communication Auteurs : P. Ferrazzoli, Auteur ; Leila Guerriero, Auteur ; Jean-Pierre Wigneron, Auteur Année de publication : 2002 Article en page(s) : pp 2700 - 2708 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] bande L [Termes IGN] emissivité [Termes IGN] forêt [Termes IGN] humidité du sol [Termes IGN] hyperfréquence [Termes IGN] modèle de transfert radiatif [Termes IGN] simulation d'image [Termes IGN] Soil Moisture and Ocean Salinity Mission Résumé : (Auteur) The microwave model developed at the Tor Vergata University is used to simulate the emissivity of forests, in order to study the performance of an L-band spaceborne radiometer, similar to that carried by the Soil Moisture Ocean Salinity mission. The model is first validated, and the importance of a correct vegetation growth parametrization in the modeling procedure is pointed out. This model is also used to calibrate a simple zeroorder radiative transfer model, since simple models have been recognized to be useful in retrieval applications at a global scale. In this paper, we show that although a zeroorder approximation cannot be directly used for forests, a simple formulation may be applied, provided the albedo and the optical depth are defined as equivalent parameters. Numéro de notice : A2002-352 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2002.807577 En ligne : https://doi.org/10.1109/TGRS.2002.807577 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22263 [article]

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065-02121	RAB	Revue	Centre de documentation	En réserve L003	Disponible