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Bidirectional reflectance of Earth targets: evaluation of analytical models using a large set of spaceborne measurements with emphasis on the Hot Spot / F. Maignan in Remote sensing of environment, vol 90 n° 2 (30/03/2004)
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Titre : Bidirectional reflectance of Earth targets: evaluation of analytical models using a large set of spaceborne measurements with emphasis on the Hot Spot Type de document : Article/Communication Auteurs : F. Maignan, Auteur ; François-Marie Bréon, Auteur ; R. Lacaze, Auteur Année de publication : 2004 Article en page(s) : pp 210 - 220 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rayonnement électromagnétique
[Termes IGN] albedo
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] image ADEOS-POLDER
[Termes IGN] réflectance
[Termes IGN] rétrodiffusion
[Termes IGN] tâche claire
[Termes IGN] transfert radiatifRésumé : (Auteur) Multidirectional observation from the spacebome POLDER (Polarization and Directionality of the Earth Reflectance) instrument makes it possible to measure the bidirectional reflectance of a large variety of Earth targets. A careful selection of cloud-free measurements with a large directional coverage lead to about 22,000 sets of measured Bidirectional Reflectance Distribution Functions (BRDFs). This data set is used to evaluate the ability of analytical models to reproduce the observed directional signatures. Among those evaluated, the best models appear to be the three-parameter linear Ross-Li model, and the nonlinear Rahman-Pinty-Verstraete (RPV) model. On the other hand, all models fail to accurately reproduce the sharp reflectance increase (hot spot) close to the backscattering direction. Based on physical considerations, we suggest a modification of the Ross-Li model, without adding a free parameter, to account for the complex radiative transfer within the canopy that leads to the hot spot signature. The modified linear model performs better than all others, including the RPV nonlinear model. Although the correction modifies the retrieved directional signature parameters, it does not change significantly the surface albedo estimates. Numéro de notice : A2004-142 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.12.006 En ligne : https://doi.org/10.1016/j.rse.2003.12.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26669
in Remote sensing of environment > vol 90 n° 2 (30/03/2004) . - pp 210 - 220[article]Cloud screening in IRS-P4 OCM satellite data: potential of spatial coherence method in the absence of thermal channel information / S.K. Nair in Remote sensing of environment, vol 90 n° 2 (30/03/2004)
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Titre : Cloud screening in IRS-P4 OCM satellite data: potential of spatial coherence method in the absence of thermal channel information Type de document : Article/Communication Auteurs : S.K. Nair, Auteur ; K. Rajeev, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 259 - 267 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] bande visible
[Termes IGN] détection
[Termes IGN] image IRS-OCM
[Termes IGN] image optique
[Termes IGN] image Seawifs
[Termes IGN] nébulosité
[Termes IGN] pixel
[Termes IGN] rayonnement proche infrarouge
[Termes IGN] seuillage d'imageRésumé : (Auteur) Cloud screening of satellite data for the remote sensing of atmospheric aerosols, ocean sediments, chlorophyll, and phytoplankton in the marine environment is a major probleme in the absence of information from thermal channel. This is particularly the case with the data from some of the highly potential satellite sensors such as the Ocean Colour Monitor (OCM-on broad the Indian Remote Sensing Satellite, IRS-P4) and the SeaWiFS. Two main tests conventionally used for cloud screening of data from such satellite sensors are the threshold method applied to visible and near-IR bands and the visible to near-IR channel ratio method. These methods do not have the potential to eliminate the pixels with a small cloud fractions, leading to overestimation of the aerosol optical depth (AOD) derived from satellite data, and might also identify the pixels with high values of AOD as cloudy. The purpose of this paper is to study the potential of Spatial Coherence Tests (SCT) applied to the data from the near-IR bands for cloud screening of satellite data over the oceanic environment. We use here the data from IRS-P4 OCM. Though more computationally intensive, the SCT does not suffer from the serious limitations of the threshold and channel ratio methods and is found to be superior in identifying the clear sky pixels that are not affected by clouds. Although the SCT applied to near-IR channel data may be overestimating the number of cloud affected pixels, it neither leads to overestimation of AOD nor identifies the pixels with high AOD values as cloudy. Numéro de notice : A2004-143 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.12.010 En ligne : https://doi.org/10.1016/j.rse.2003.12.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26670
in Remote sensing of environment > vol 90 n° 2 (30/03/2004) . - pp 259 - 267[article]Comparison of land surface emissivity and radiometric temperature derived from MODIS and ASTER sensors / F. Jacob in Remote sensing of environment, vol 90 n° 2 (30/03/2004)
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Titre : Comparison of land surface emissivity and radiometric temperature derived from MODIS and ASTER sensors Type de document : Article/Communication Auteurs : F. Jacob, Auteur ; F. Petitcolin, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 137 - 152 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse comparative
[Termes IGN] correction atmosphérique
[Termes IGN] emissivité
[Termes IGN] image Terra-ASTER
[Termes IGN] image Terra-MODIS
[Termes IGN] savane
[Termes IGN] température au sol
[Termes IGN] transfert radiatif
[Termes IGN] zone semi-arideRésumé : (Auteur) This study compared surface emissivity and radiometric temperature retrievals derived from data collected with the MODerate resolution Imaging Spectroradionieter (MODIS) and Advanced Spacebome Thermal Emission Reflection Radiometer (ASTER) sensors, onboard the NASA's Earth Observation System (EOS)-TERRA satellite. Two study sites were selected: a semi-arid area located in northern Chilmalman desert, USA, and a Savannah landscape located in central Africa. Atmospheric corrections were performed using the MODTRAN 4 atmospheric radiative transfer code along with atmospheric profiles generated by the National Center for Environmental Predictions (NCEP). Atmospheric radiative properties were derived from MODTRAN 4 calculations according to the sensor swaths, which yielded different strategies from one sensor to the other. The MODIS estimates were then computed using a designed Temperature-Independent Spectral Indices of Emissivity (TISIE) method. The ASTER estimates were derived using the Temperature Emissivity Separation (TES) algorithm. The MODIS and ASTER radiometric temperature retrievals were in good agreement when the atmospheric corrections were similar, with differences lower than 0.9 K. The emissivity estimates were compared for MODIS/ASTER matching bands at 8.5 and 11um. It was shown that the retrievals agreed well, with RMSD ranging from 0.005 to 0.0 15, and biases ranging from - 0.0 1 to 0.005. At 8.5 um, the ranges of emissivities from both sensors were very similar. At 11 um, however, the ranges of MODIS values were broader than those of the ASTER estimates. The larger MODIS values were ascribed to the gray body problem of the TES algorithm, whereas the lower MODIS values were not consistent with field references. Finally, we assessed the combined effects of spatial variability and sensor resolution. It was shown that for the study areas we considered, these effects were not critical. Numéro de notice : A2004-140 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.11.015 En ligne : https://doi.org/10.1016/j.rse.2003.11.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26667
in Remote sensing of environment > vol 90 n° 2 (30/03/2004) . - pp 137 - 152[article]Topographic information of sand dunes as extracted from shading effects using Landsat images / N. Levin in Remote sensing of environment, vol 90 n° 2 (30/03/2004)
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Titre : Topographic information of sand dunes as extracted from shading effects using Landsat images Type de document : Article/Communication Auteurs : N. Levin, Auteur ; Eyal Ben-Dor, Auteur ; A. Karnieli, Auteur Année de publication : 2004 Article en page(s) : pp 190 - 209 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] analyse comparative
[Termes IGN] angle azimutal
[Termes IGN] appariement d'histogramme
[Termes IGN] dénivelée
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] dune
[Termes IGN] extraction du relief
[Termes IGN] image Landsat-ETM+
[Termes IGN] image Landsat-TM
[Termes IGN] image multitemporelle
[Termes IGN] image Terra-ASTER
[Termes IGN] Israël
[Termes IGN] ombre
[Termes IGN] pente
[Termes IGN] réflectanceRésumé : (Auteur) Topographic variations affect the reflectance properties of the Earth's surface and are often removed in remote sensing studies. especially when significant terrain variations exist. In this study, however, we show that shading effects assessed by Landsat can be treated as a signal that stores important topographic information, especially when the spectral characteristics of a surface are homogenous. The coastal transverse dunes of the Ashdod area, and the desert linear dunes of Nizzana (both located in Israel), were selected to investigate the above-mentioned idea. The dune heights in these areas are 10 m on average (relative to their surroundings) and have maximum slopes of 33°. An innovative method for extracting slope, aspect, and height data for sand dunes using Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) images was developed, based on the regularity and periodicity of dunes landscapes. Using two Landsat images representing different sun zenith and azimuth angles, reflectance values of each image were converted to cos(i) values (i =incident angle between the surface normal and the solar beam radiation), applying histogram matching methods. The slope and aspect of each pixel were determined as those that give the best prediction of the observed value of cos(i). Height profiles were then extracted, using simple trigonometric relationships. The accuracies of heights and slopes along selected profile lines were to the order of 1 m and 3°, respectively (at a spatial resolution of 15 m). Best results were obtained when the images included one from the summer and the other from the winter, corresponding to maximum difference in solar zenith and azimuth angles. Errors in heights were attributed to surface heterogeneity (e.g., presence of biogenic soil crusts in the rainy season), geometric correction errors, cast shadows, and Bidirectional Reflectance Distribution Function (BRDF) effects. Comparison to Advanced Thermal Emission and Reflection Radiometer (ASTER) 3D information showed that the proposed method is better in representing the topographic variation of the area than the digital elevation model (DEM) produced by ASTER. Numéro de notice : A2004-141 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.12.008 En ligne : https://doi.org/10.1016/j.rse.2003.12.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26668
in Remote sensing of environment > vol 90 n° 2 (30/03/2004) . - pp 190 - 209[article]Smoothing vegetation spectra with wavelets / K.S. Schmidt in International Journal of Remote Sensing IJRS, vol 25 n° 6 (March 2004)
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Titre : Smoothing vegetation spectra with wavelets Type de document : Article/Communication Auteurs : K.S. Schmidt, Auteur ; Andrew K. Skidmore, Auteur Année de publication : 2004 Article en page(s) : pp 1167 - 1184 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] filtrage numérique d'image
[Termes IGN] lissage de données
[Termes IGN] ondelette
[Termes IGN] réflectance spectrale
[Termes IGN] télédétection en hyperfréquenceRésumé : (Auteur) In hyperspectral remote sensing, spectra are increasingly analysed using methods developed for laboratory studies, such as derivative analysis. These techniques require smooth reflectance spectra. Therefore, there is a need for smoothing algorithms that fulfil the requirement of preserving local spectral features while simultaneously removing noise. Noise occurs in variable intensity and over different band widths. Several methods for smoothing a signal exist, including the widely used median and mean filters, the Savitzky-Golay filter applied to laboratory spectra, the cubic spline, and the recently developed transform-based thresholding using the wavelet transform. We compare all these methods using reflectance spectra of the canopy of salt marsh vegetation. The best trade-off between noise reduction and the preservation of spectral features was found to be the wavelet transform, specifically using a translation invariant de-noising based on the non-decimated or stationary wavelet transform. Numéro de notice : A2004-087 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116031000115085 En ligne : https://doi.org/10.1080/0143116031000115085 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26614
in International Journal of Remote Sensing IJRS > vol 25 n° 6 (March 2004) . - pp 1167 - 1184[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04061 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Airborne measurement of hot spot reflectance signatures / F. Camacho-De Coca in Remote sensing of environment, vol 90 n° 1 (15/03/2004)
PermalinkIntegrating imaging spectroscopy and neural networks to map grass quality in the Kruger National Park, South Africa / Onisimo Mutanga in Remote sensing of environment, vol 90 n° 1 (15/03/2004)
PermalinkThe spatial distribution of indigenous forest and its composition in the Wellington region, New Zealand, from ETM+ satellite imagery / J.R. Dymond in Remote sensing of environment, vol 90 n° 1 (15/03/2004)
PermalinkSurveillance et cartographie des plans d'eau et des zones humides et inondables en régions arides avec l'instrument Végétation embarqué sur SPOT-4 / Valéry Gond in International Journal of Remote Sensing IJRS, vol 25 n° 5 (March 2004)
PermalinkAssessing the potential of space-borne C-band SAR data for spatial soil moisture information over a large area / S.A. Romshoo in Geocarto international, vol 19 n° 1 (March - May 2004)
PermalinkA basis for estimating digital camera parameters / D. Light in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 3 (March 2004)
PermalinkEffets radiométriques en milieu urbain à grande échelle et correction des ombres / Gilles Martinoty in Géomatique expert, n° 32 (01/03/2004)
PermalinkQuelques réflexions sur la réfraction d'un rayon lumineux dans l'air / R. Vincent in XYZ, n° 98 (mars - mai 2004)
PermalinkReducing the dimensionality of plant spectral databases / I.E. Bell in IEEE Transactions on geoscience and remote sensing, vol 42 n° 3 (March 2004)
PermalinkThe effect of scene elevation on the coherence of wide-angle crossing-node SAR pairs / T.M. Payne in IEEE Transactions on geoscience and remote sensing, vol 42 n° 3 (March 2004)
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