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Auteur Andrew K. Skidmore |
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The potential of spectral mixture analysis to improve the estimation accuracy of tropical forest biomass / T.M. Basuki in Geocarto international, vol 27 n° 4 (July 2012)
[article]
Titre : The potential of spectral mixture analysis to improve the estimation accuracy of tropical forest biomass Type de document : Article/Communication Auteurs : T.M. Basuki, Auteur ; Andrew K. Skidmore, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 329 - 345 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse des mélanges spectraux
[Termes IGN] biomasse
[Termes IGN] estimation statistique
[Termes IGN] forêt tropicale
[Termes IGN] image Landsat-ETM+
[Termes IGN] Indonésie
[Termes IGN] régressionRésumé : (Auteur) A main limitation of pixel-based vegetation indices or reflectance values for estimating above-ground biomass is that they do not consider the mixed spectral components on the earth's surface covered by a pixel. In this research, we decomposed mixed reflectance in each pixel before developing models to achieve higher accuracy in above-ground biomass estimation. Spectral mixture analysis was applied to decompose the mixed spectral components of Landsat-7 ETM+ imagery into fractional images. Afterwards, regression models were developed by integrating training data and fraction images. The results showed that the spectral mixture analysis improved the accuracy of biomass estimation of Dipterocarp forests. When applied to the independent validation data set, the model based on the vegetation fraction reduced 5–16% the root mean square error compared to the models using a single band 4 or 5, multiple bands 4, 5, 7 and all non-thermal bands of Landsat ETM+. Numéro de notice : A2012-334 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2011.634928 Date de publication en ligne : 05/12/2011 En ligne : https://doi.org/10.1080/10106049.2011.634928 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31780
in Geocarto international > vol 27 n° 4 (July 2012) . - pp 329 - 345[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-2012041 RAB Revue Centre de documentation En réserve L003 Disponible vol 25 n° 3 - march 2011 - Spatial ecology (Bulletin de International journal of geographical information science IJGIS) / Andrew K. Skidmore
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Titre : vol 25 n° 3 - march 2011 - Spatial ecology Type de document : Périodique Auteurs : Andrew K. Skidmore, Éditeur scientifique ; Janet Franklin, Éditeur scientifique ; Terry Dawson, Éditeur scientifique ; et al., Auteur Année de publication : 2011 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] écologieNuméro de notice : 079-201102 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Numéro de périodique Permalink : https://documentation.ensg.eu/index.php?lvl=bulletin_display&id=26371 [n° ou bulletin]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-2011021 RAB Revue Centre de documentation En réserve L003 Disponible Continuum removed band depth analysis for detecting the effects of natural gas, methane and ethane reflectance / M.F. Noomen in Remote sensing of environment, vol 105 n° 3 (15/12/2006)
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Titre : Continuum removed band depth analysis for detecting the effects of natural gas, methane and ethane reflectance Type de document : Article/Communication Auteurs : M.F. Noomen, Auteur ; Andrew K. Skidmore, Auteur ; Freek Van Der Meer, Auteur ; Herbert H.T. Prins, Auteur Année de publication : 2006 Article en page(s) : pp 262 - 270 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande visible
[Termes IGN] gaz naturel
[Termes IGN] photosynthèse
[Termes IGN] réflectance végétale
[Termes IGN] santé
[Termes IGN] spectrophotométrie
[Termes IGN] végétationRésumé : (Auteur) It is known that natural gas in the soil affects vegetation health, which may be detected through analysis of reflectance spectra. Since natural gas is invisible, changes in the vegetation could potentially indicate gas leakage. Although it is known that gas in soil affects plant reflectance, the relationship between natural gas and the development and reflectance properties of plants has not been studied. The objective of this study was to test whether natural gas and its two main components, methane and ethane, affect vegetation reflectance in the chlorophyll and water absorption regions. An experiment was carried out in which maize (Zea mays) plants were grown in pots that were flushed with 10 l of gas per day for 39 + 4 days. Leaf reflectance was measured once a week with a spectrophotometer. The reflectance was analysed using continuum removal of the blue (400–550 nm), red (550–750 nm) and two water absorption features (1370–1570 nm and 1870–2170 nm), after which the band depths and normalized band depths were analyzed for each treatment. The band depth analysis showed that ethane caused an initial increase of 10% in reflectance between 560 and 590 nm, followed by a decrease during the course of the experiment. Normalized band depth analysis showed that ethane caused a reflectance shift of 1 to 5 nm towards longer wavelengths compared to the control reflectance in the visible region. All gases caused an increase in reflectance in the water absorption bands. The physiological reflectance index, PRI, which has previously linked water stress to photosynthetic activity, suggested that the hydrocarbon gases (particularly ethane) decreased the photosynthetic activity of the plants. The combination of reduced band depths in the chlorophyll and water absorption regions and the increased PRI suggests that ethane gas in the soil hampered a normal water uptake by maize plants in an early stage of their growth. Although further research is necessary to upscale the results from the laboratory to the field, the increased reflectance in the 560–590 nm region caused by ethane together with the increased PRI are promising indicators for gas leakage. Copyright Elsevier Numéro de notice : A2006-558 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2006.07.009 En ligne : https://doi.org/10.1016/j.rse.2006.07.009 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28281
in Remote sensing of environment > vol 105 n° 3 (15/12/2006) . - pp 262 - 270[article]Estimating tropical pasture quality at canopy level using band depth analysis with continuum removal in the visible domain / Onisimo Mutanga in International Journal of Remote Sensing IJRS, vol 26 n° 6 (March 2005)
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Titre : Estimating tropical pasture quality at canopy level using band depth analysis with continuum removal in the visible domain Type de document : Article/Communication Auteurs : Onisimo Mutanga, Auteur ; Andrew K. Skidmore, Auteur ; et al., Auteur Année de publication : 2005 Article en page(s) : pp 1093 - 1108 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse spectrale
[Termes IGN] bande visible
[Termes IGN] contrôle qualité
[Termes IGN] faune
[Termes IGN] forêt tropicale
[Termes IGN] herbe
[Termes IGN] paturage
[Termes IGN] radiométrie
[Termes IGN] réflectance végétale
[Termes IGN] régression linéaire
[Termes IGN] zone intertropicaleRésumé : (Auteur) Pasture quality, expressed as a percentage of total digestible nutients (nitrogen, potassium, phosphorous, calcium and magnesium) is a major factor determining the grazing patterns of wildlife and livestock. Existing rangeland monitoring techniques seldom reflect the nutritive quality of the pastures and are consequently of limited value in explaining animal distribution. Techniques that can estimate pasture quality on a large scale are therefore critical in understanding and explaining wildlife and livestock distribution. We present the results of a greenhouse experiment designed to estimate the concentrations of nitrogen, potassium, phosphorous calcium, magnesium and non-detergent fibre (NDF), using the reflectance of a tropical grass (Cenchrus ciliaris) canopy. Canopy spectral measurements were taken under controlled laboratory conditins using a GER 3700 spectroradiometer. We tested the utility of using the band depth analysis methodology in the visible region (where water absorption is less effective) to estimate foliar chemistry in fresh canopies. Continuum removal was applied to the visible absorption feature centred at 670 nm, and band depth ratios (BDRs) were calculated. Stepwise linear regression was used to select wavelenghts from calculated BDRs that were highly correlated with foliar chemistry in randomly selected training dataset. The resulting regression models were used to predict foliar chemistry in a test dataset. Results indicate that stepwise regression models on band calculated from continuum-removed reflectance spectra could predict foliar nutrient concentration with high accuracy. The correlations were highest for magnesium and nitrogen (R2= 0.77 and 0.73 respectively, using the normalized band depth index (NDBI) between the measured and estimated biochemicals - a satisfactory result in estimating foliar chemistry in fresh standing pastures. With the advent of new sensors such as Hymap and MERIS these results lay the basis for developing algorithms to rapidly estimate and ultimately map pasture quality in tropical rangelands. Numéro de notice : A2005-145 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160512331326738 En ligne : https://doi.org/10.1080/01431160512331326738 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27283
in International Journal of Remote Sensing IJRS > vol 26 n° 6 (March 2005) . - pp 1093 - 1108[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-05061 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Mapping coastal vegetation using an expert system and hyperspectral imagery / K.S. Schmidt in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 6 (June 2004)
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Titre : Mapping coastal vegetation using an expert system and hyperspectral imagery Type de document : Article/Communication Auteurs : K.S. Schmidt, Auteur ; Andrew K. Skidmore, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 703 - 715 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse comparative
[Termes IGN] carte de la végétation
[Termes IGN] classification
[Termes IGN] image hyperspectrale
[Termes IGN] littoral
[Termes IGN] marais salé
[Termes IGN] Pays-Bas
[Termes IGN] photo-interprétation
[Termes IGN] photo-interprétation assistée par ordinateur
[Termes IGN] photographie aérienne
[Termes IGN] plante halophile
[Termes IGN] système expertRésumé : (Auteur) Mapping and monitoring saltmarshes in the Netherlands are important activities of the Ministry of Public Works (Rijkswaterstaot). The Survey Department (Meetkundige Dienst) produces vegetation maps using aerial photographs. However, it is a time-consuming and expensive activity. The accuracy of the conventional vegetation map derived using aerial photograph interpretation (API) is estimated to be around 43 percent. In this study, an alternative method is demonstrated that uses an expert system to combine airborne hyperspectral imagery with terrain data derived from radar altimetry The accuracy of the vegetation map generated by the expert system increased to 66 percent. When hyperspectral imagery alone was used to classify coastal wetlands, an accuracy of 40 percent was achieved-comparable to the accuracy of the API-derived vegetation map. An analysis of the efficiency of the proposed expert system showed that the speed of map production is increased by using the new method. This means that digital image classification using the expert system is an objective and repeatable method superior to the conventional API method. Numéro de notice : A2004-205 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.70.6.703 En ligne : https://doi.org/10.14358/PERS.70.6.703 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26732
in Photogrammetric Engineering & Remote Sensing, PERS > vol 70 n° 6 (June 2004) . - pp 703 - 715[article]Smoothing vegetation spectra with wavelets / K.S. Schmidt in International Journal of Remote Sensing IJRS, vol 25 n° 6 (March 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)PermalinkPredicting in situ pasture quality in the Kruger National Park, South Africa, using continuum-removed absorption features / Onisimo Mutanga in Remote sensing of environment, vol 89 n° 3 (15/02/2004)PermalinkIntegration of classification methods for improvement of land-cover map accuracy / XiaoHang Liu in ISPRS Journal of photogrammetry and remote sensing, vol 56 n° 4 (July - August 2002)PermalinkAn expert system classifies eucalypt forest types using Thematic Mapper data and a digital terrain model / Andrew K. Skidmore in Photogrammetric Engineering & Remote Sensing, PERS, vol 55 n° 10 (october 1989)PermalinkUnsupervised training area selection in forests using a nonparametric distance measure and spatial information / Andrew K. Skidmore in International Journal of Remote Sensing IJRS, vol 10 n° 1 (January 1989)PermalinkForest mapping accuracies are improved using a supervised nonparametric classifier with Spot data / Andrew K. Skidmore in Photogrammetric Engineering & Remote Sensing, PERS, vol 54 n° 10 (october 1988)PermalinkNon-parametric test of overlap in multispectral classification / Andrew K. Skidmore in International Journal of Remote Sensing IJRS, vol 9 n° 4 (April 1988)PermalinkAn explanation of enhanced radar backscattering from flooded forests / J.A. Richards in International Journal of Remote Sensing IJRS, vol 8 n° 7 (July 1987)Permalink