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Influence of macroscale and microscale surface roughness on multi-beam RADARSAT-1 data: implications for geological mapping in the Curaçá Valley, Brazil / W.R. Paradella in Photo interprétation, European journal of applied remote sensing, vol 45 n° 2 (juin 2009)

Public [article]  inPhoto interprétation, European journal of applied remote sensing > vol 45 n° 2 (juin 2009) . - pp 51 - 61 Titre : Influence of macroscale and microscale surface roughness on multi-beam RADARSAT-1 data: implications for geological mapping in the Curaçá Valley, Brazil Type de document : Article/Communication Auteurs : W.R. Paradella, Auteur ; S. Knust, Auteur ; A. Dos Santos, Auteur ; et al., Auteur Année de publication : 2009 Article en page(s) : pp 51 - 61 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse en composantes principales [Termes IGN] angle d'incidence [Termes IGN] Brésil [Termes IGN] carte géologique [Termes IGN] géologie structurale [Termes IGN] image Radarsat [Termes IGN] niveau d'analyse [Termes IGN] rugosité du sol [Termes IGN] topographie locale [Termes IGN] vallée [Termes IGN] zone semi-aride Résumé : (Auteur) The dependence of the radar backscatter on macro and microtopography was examined through a collection of multi-beam RADARSAT-I imagery acquired under ascending and descending passes over the Curaça Valley, Northeastern Brazil. Firstly, the influence of both surface roughness regimes on the images was qualitatively evaluated through the use of Principal Component Analysis (PCA). The backscatter variability was emphasized using PCA since the components are linear combinations of all input radar target contributions within the original scenes. Secondly, the research addressed the quantitative influence of the microtopography on RADARSAT-1 Ó0 values through the use of statistical parameters derived from surface roughness profiles of distinct rock alteration products. The investigation has shown that the use of PCA on RADARSAT-1 imagery with distinct look-direction and incidence angles is a suitable technique for highlighting backscattering variability from distinct targets within each scene expressed by tonal and textural patterns. These image patterns reflected a combination of effects related to large-scale surface slope (scarps, crests, positive and negative topographic breaks, etc.) and to ground cover (surface roughness of rock outcrops, residual soils and vegetation cover). The topographic enhancement provided by the RADARSAT-1 PC2, PC3 and PC4 showed to be excellent for structural mapping. In addition, varia-tion in look-azimuth was more important than incidence changes in the enhancement of subtle geomorphic features, often an expression of geological structures and underlying lithology. Finally, the quantitative evaluation of the dependence of Ó0 on micro-scale surface roughness confirmed that the SAR backscattering was not controlled in a predominant manner by the microtopographic variations of the geological surfaces. Copyright Editions Eska Numéro de notice : A2009-522 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30151 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
104-09021	SL	Revue	Centre de documentation	Revues en salle	Exclu du prêt

The application of Advanced Space-Borne Thermal Emission and Reflection (ASTER) radiometer data in the detection of alteration paleocrater, Bafq region, central Iran / A. Moghtaderi in Photo interprétation, European journal of applied remote sensing, vol 45 n° 2 (juin 2009)

Public [article]  inPhoto interprétation, European journal of applied remote sensing > vol 45 n° 2 (juin 2009) . - pp 79 - 87 Titre : The application of Advanced Space-Borne Thermal Emission and Reflection (ASTER) radiometer data in the detection of alteration paleocrater, Bafq region, central Iran Type de document : Article/Communication Auteurs : A. Moghtaderi, Auteur ; F. Moore, Auteur ; Ali Mohammadzadeh, Auteur Année de publication : 2009 Article en page(s) : pp 79 - 87 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] altération géologique [Termes IGN] capteur multibande [Termes IGN] composition colorée [Termes IGN] cratère [Termes IGN] image optique [Termes IGN] image Terra-ASTER [Termes IGN] Iran [Termes IGN] minéralogie [Termes IGN] réflectance du sol [Termes IGN] traitement d'image Résumé : (Auteur) Ore deposits are often produced by fluid flow processes that basically alter the mineralogy and chemistry of the country rock. One of the important objectives of developed multispectral and a hyper-spectral sensor is to detect optical characteristics of the Earth surface using hundreds of spectral bands. All previous studies show that remote sensing can recognize alteration to different degrees using different spatial and spectral resolution sensors. ASTER sensor measures reflected radiation in VNIR, SWIR and TIR electromagnetic energies. It's cheap and easily available. The alteration minerals of Chadormalu area (Chadormalu paleocrater and the related iron oxide deposit) are investigated in the field and successfully detected by applying IARR (Internal Average Relative Reflectance), FCC (False Color Composite), Decorrelation-stretch, MNF (Minimum Noise Fraction Transform), correlated filter and MEM (Mathematical Evaluation Method) techniques on ASTER imageries. Sadie, potassic, and silicic-sericitisation alteration patterns are distinguished. This studv shows that, the ability and accuracy of MEM method is better than 2*2 correlated filter techniques. The results indicate that, pervasive hydrothermal ore-forming processes are important at the study area. Judging from alteration mineral assemblages, it may be said that Chadormalu iron deposit is an endmember of the Kiruna type -Iron oxide (Cu-Au) ore deposit continuum. Numéro de notice : A2009-523 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30152 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
104-09021	SL	Revue	Centre de documentation	Revues en salle	Exclu du prêt