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Commercial tree species discrimination using airborne AISA Eagle hyperspectral imagery and partial least squares discriminant analysis (PLS-DA) in KwaZulu–Natal, South Africa / Kabir Yunus Peerbhay in ISPRS Journal of photogrammetry and remote sensing, vol 79 (May 2013)
[article]
Titre : Commercial tree species discrimination using airborne AISA Eagle hyperspectral imagery and partial least squares discriminant analysis (PLS-DA) in KwaZulu–Natal, South Africa Type de document : Article/Communication Auteurs : Kabir Yunus Peerbhay, Auteur ; Onisimo Mutanga, Auteur ; Riyad Ismail, Auteur Année de publication : 2013 Article en page(s) : pp 19 - 28 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] Afrique du sud (état)
[Termes IGN] analyse discriminante
[Termes IGN] arbre (flore)
[Termes IGN] classification dirigée
[Termes IGN] espèce végétale
[Termes IGN] forêt
[Termes IGN] image AISA+
[Termes IGN] image hyperspectrale
[Termes IGN] méthode des moindres carrésRésumé : (Auteur) Discriminating commercial tree species using hyperspectral remote sensing techniques is critical in monitoring the spatial distributions and compositions of commercial forests. However, issues related to data dimensionality and multicollinearity limit the successful application of the technology. The aim of this study was to examine the utility of the partial least squares discriminant analysis (PLS-DA) technique in accurately classifying six exotic commercial forest species (Eucalyptus grandis, Eucalyptus nitens, Eucalyptus smithii, Pinus patula, Pinus elliotii and Acacia mearnsii) using airborne AISA Eagle hyperspectral imagery (393–900 nm). Additionally, the variable importance in the projection (VIP) method was used to identify subsets of bands that could successfully discriminate the forest species. Results indicated that the PLS-DA model that used all the AISA Eagle bands (n = 230) produced an overall accuracy of 80.61% and a kappa value of 0.77, with user’s and producer’s accuracies ranging from 50% to 100%. In comparison, incorporating the optimal subset of VIP selected wavebands (n = 78) in the PLS-DA model resulted in an improved overall accuracy of 88.78% and a kappa value of 0.87, with user’s and producer’s accuracies ranging from 70% to 100%. Bands located predominantly within the visible region of the electromagnetic spectrum (393–723 nm) showed the most capability in terms of discriminating between the six commercial forest species. Overall, the research has demonstrated the potential of using PLS-DA for reducing the dimensionality of hyperspectral datasets as well as determining the optimal subset of bands to produce the highest classification accuracies. Numéro de notice : A2013-231 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2013.01.013 En ligne : https://doi.org/10.1016/j.isprsjprs.2013.01.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32369
in ISPRS Journal of photogrammetry and remote sensing > vol 79 (May 2013) . - pp 19 - 28[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2013051 RAB Revue Centre de documentation En réserve L003 Disponible A robust signal preprocessing chain for small-footprint waveform LiDAR / J. Wu in IEEE Transactions on geoscience and remote sensing, vol 50 n° 8 (August 2012)
[article]
Titre : A robust signal preprocessing chain for small-footprint waveform LiDAR Type de document : Article/Communication Auteurs : J. Wu, Auteur ; Jan Van Aardt, Auteur ; J. Mcglinchy, Auteur ; Gregory P. Asner, Auteur Année de publication : 2012 Article en page(s) : pp 3242 - 3255 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Afrique du sud (état)
[Termes IGN] biomasse
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] étalonnage
[Termes IGN] forme d'onde
[Termes IGN] lasergrammétrie
[Termes IGN] prétraitement du signal
[Termes IGN] savane
[Termes IGN] signal lidarRésumé : (Auteur) The extraction of structural object metrics from a next-generation remote sensing modality, namely waveform Light Detection and Ranging (LiDAR), has garnered increasing interest from the remote sensing research community. However, the raw incoming (received) LiDAR waveform typically exhibits a stretched, misaligned, and relatively distorted character. In other words, the LiDAR signal is smeared and the effective temporal (vertical) resolution decreases, which is attributed to a fixed time span allocated for detection, the sensor's variable outgoing pulse signal, off-nadir scanning, the receiver impulse response impacts, and system noise. Theoretically, such a loss of resolution and increased data ambiguity can be remediated by using proven signal preprocessing approaches. In this paper, we present a robust signal preprocessing chain for waveform LiDAR calibration, which includes noise reduction, deconvolution, waveform registration, and angular rectification. This preprocessing chain was initially validated using simulated waveform data, which were derived via the digital imaging and remote sensing image generation modeling environment. We also verified the approach using real small-footprint waveform LiDAR data collected by the Carnegie Airborne Observatory in a savanna region of South Africa and specifically in terms of modeling woody biomass in this region. Metrics, including the spectral angle for cross-section recovery assessment and goodness-of-fit (R2) statistics, along with the root-mean-squared error for woody biomass estimation, were used to provide a comprehensive quantitative evaluation of the performance of this preprocessing chain. Results showed that our approach significantly increased our ability to recover the temporal signal resolution, improved geometric rectification of raw waveform LiDAR, and resulted in improved waveform-based woody biomass estimation. This preprocessing chain has the potential to be applied across the board for h- gh fidelity processing of small-footprint waveform LiDAR data, thereby facilitating the extraction of valid and useful structural metrics from ground objects. Numéro de notice : A2012-389 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2011.2178420 Date de publication en ligne : 04/01/2012 En ligne : https://doi.org/10.1109/TGRS.2011.2178420 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31835
in IEEE Transactions on geoscience and remote sensing > vol 50 n° 8 (August 2012) . - pp 3242 - 3255[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2012081 RAB Revue Centre de documentation En réserve L003 Disponible Classification of savanna tree species, in the Greater Kruger National Park region, by integrating hyperspectral and LiDAR data in a Random Forest data mining environment / Laven Naidoo in ISPRS Journal of photogrammetry and remote sensing, vol 69 (April 2012)
[article]
Titre : Classification of savanna tree species, in the Greater Kruger National Park region, by integrating hyperspectral and LiDAR data in a Random Forest data mining environment Type de document : Article/Communication Auteurs : Laven Naidoo, Auteur ; Moses Azong Cho, Auteur ; Renaud Mathieu, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 167 - 179 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] Afrique du sud (état)
[Termes IGN] arbre (flore)
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] hauteur des arbres
[Termes IGN] image hyperspectrale
[Termes IGN] lasergrammétrie
[Termes IGN] parc naturel national
[Termes IGN] savaneRésumé : (Auteur) The accurate classification and mapping of individual trees at species level in the savanna ecosystem can provide numerous benefits for the managerial authorities. Such benefits include the mapping of economically useful tree species, which are a key source of food production and fuel wood for the local communities, and of problematic alien invasive and bush encroaching species, which can threaten the integrity of the environment and livelihoods of the local communities. Species level mapping is particularly challenging in African savannas which are complex, heterogeneous, and open environments with high intra-species spectral variability due to differences in geology, topography, rainfall, herbivory and human impacts within relatively short distances. Savanna vegetation are also highly irregular in canopy and crown shape, height and other structural dimensions with a combination of open grassland patches and dense woody thicket – a stark contrast to the more homogeneous forest vegetation. This study classified eight common savanna tree species in the Greater Kruger National Park region, South Africa, using a combination of hyperspectral and Light Detection and Ranging (LiDAR)-derived structural parameters, in the form of seven predictor datasets, in an automated Random Forest modelling approach. The most important predictors, which were found to play an important role in the different classification models and contributed to the success of the hybrid dataset model when combined, were species tree height; NDVI; the chlorophyll b wavelength (466 nm) and a selection of raw, continuum removed and Spectral Angle Mapper (SAM) bands. It was also concluded that the hybrid predictor dataset Random Forest model yielded the highest classification accuracy and prediction success for the eight savanna tree species with an overall classification accuracy of 87.68% and KHAT value of 0.843. Numéro de notice : A2012-199 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2012.03.005 En ligne : https://doi.org/10.1016/j.isprsjprs.2012.03.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31646
in ISPRS Journal of photogrammetry and remote sensing > vol 69 (April 2012) . - pp 167 - 179[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2012031 SL Revue Centre de documentation Revues en salle Disponible Laser scanning in heritage documentation: The scanning pipeline and its challenges / H. Ruther in Photogrammetric Engineering & Remote Sensing, PERS, vol 78 n° 4 (April 2012)
[article]
Titre : Laser scanning in heritage documentation: The scanning pipeline and its challenges Type de document : Article/Communication Auteurs : H. Ruther, Auteur ; R. Bhurtha, Auteur ; C. Held, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 309 - 316 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Afrique du sud (état)
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] patrimoine culturel
[Termes IGN] semis de points
[Termes IGN] TanzanieRésumé : (Auteur) In an attempt to show the complexity of terrestrial laser scanning of heritage sites and dispel the not infrequently found perception of a largely automated tool with close to real time processing capabilities, the individual steps of the data acquisition and processing pipeline, including registration, point cloud cleaning, surface reconstruction, hole filling, texturing and final output are discussed. Emphasized are areas in which further development and research are desirable. A brief discussion of the concepts and implementation of the African Cultural Heritage Sites and Landscapes Project, as executed by the Zamani Research Group at the University of Cape Town, is incorporated into the paper. This database integrates spatial and non-spatial data and focuses on architectural heritage sites and cultural landscapes. The spatial data comprises of 3D laser scans, GIS's for each site and its environment, stereo images, panoramas, ground plans, elevations and sections derived from laser scan models, contextual photography and videos as well as 3D landscape models. The database is primarily designed as a resource for research and higher education. However, the spatial data acquired for the project are presently used in a number of restoration and conservation projects. An important further objective is the creation of a permanent digital record. The project, funded by the Andrew W. Mellon Foundation, is a joint initiative of the Zamani Research Group at the University of Cape Town and JStor, New York. Numéro de notice : A2012-176 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.78.4.309 En ligne : https://doi.org/10.14358/PERS.78.4.309 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31623
in Photogrammetric Engineering & Remote Sensing, PERS > vol 78 n° 4 (April 2012) . - pp 309 - 316[article]Evaluating terrestrial water storage variations from regionally constrained GRACE mascon data and hydrological models over Southern Africa: preliminary results / P. Krogh in International Journal of Remote Sensing IJRS, vol 31 n° 14 (July 2010)
[article]
Titre : Evaluating terrestrial water storage variations from regionally constrained GRACE mascon data and hydrological models over Southern Africa: preliminary results Type de document : Article/Communication Auteurs : P. Krogh, Auteur ; O. Andersen, Auteur ; C. Michailovsky, Auteur ; et al., Auteur Année de publication : 2010 Article en page(s) : pp 3899 - 3912 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Afrique du sud (état)
[Termes IGN] champ de pesanteur local
[Termes IGN] données GRACE
[Termes IGN] Malawi
[Termes IGN] modèle hydrographique
[Termes IGN] ressources en eau
[Termes IGN] variable régionalisée
[Termes IGN] variationRésumé : (Auteur) A concentration of surface mass has a distinct, localized signature in Gravity Recovery and Climate Experiment (GRACE) K-band range rate (KBRR) data. This fact is exploited in the regional solutions for mass concentration parameters (mascons) made at the Goddard Space Flight Center (GSFC). In this paper we explore an experimental set of regionally constrained mascon blocks over Southern Africa where a system of 1.25° times 1.5° and 1.5° times 1.5° blocks has been designed. The blocks are divided into hydrological regions based on drainage patterns of the largest river basins, and are constrained in different ways. We show that the use of regional constraints, when solving mascon parameters of different hydrological regions independently, yields more detail and variation than comparable spherical harmonic solutions and mascon solutions using isotropic constraints. We validate our results over Lake Malawi with water level from altimetry. Results show that weak constraints across regions in addition to intra-regional constraints are necessary, to reach reasonable mass variations. Numéro de notice : A2010-372 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431161.2010.483483 En ligne : https://doi.org/10.1080/01431161.2010.483483 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30566
in International Journal of Remote Sensing IJRS > vol 31 n° 14 (July 2010) . - pp 3899 - 3912[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-2010091 RAB Revue Centre de documentation En réserve L003 Exclu du prêt n° 203 - mars 2010 - Journée d'étude du secteur cartographique de l'IRD, [actes, Bondy, septembre 2009] (Bulletin de Le monde des cartes) / Comité français de cartographiePermalinkAddress databases for national SDI: Comparing the novel data grid approach to data harvesting and federated databases / Serena Coetzee in International journal of geographical information science IJGIS, vol 23 n°9-10 (september 2009)PermalinkTerritories and urbanisation in South Africa / F. Giraut (2009)PermalinkEnjeux de mots : les changements toponymiques sud-africains / F. Giraut in Espace géographique, vol 37 n° 2 (avril - juin 2008)PermalinkEspace représenté, espace dénommé / J.C. Herbin (2007)PermalinkGIS for HIV/aids management: open source GIS development in South Africa / B. Vanmeulebrouk in GIM international, vol 20 n° 3 (March 2006)PermalinkAssessing the effects of human-induced land degradation in the former homelands of northern South Africa with a 1 km AVHRR NDVI time-series / K.J. Wessels in Remote sensing of environment, vol 91 n° 1 (15/05/2004)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)PermalinkAnalysing cadastral systems in uncertain situations: a conceptual framework based on soft systems theory / Michael Barry in International journal of geographical information science IJGIS, vol 16 n° 1 (january 2002)Permalink