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Creation of DTM with ASTER data and statistical verification of the accuracy of the model (western Peloponnese, Greece) / N. Konstantinos in Geocarto international, vol 19 n° 1 (March - May 2004)  

Public [article]  inGeocarto international > vol 19 n° 1 (March - May 2004) . - pp 3 - 9 Titre : Creation of DTM with ASTER data and statistical verification of the accuracy of the model (western Peloponnese, Greece) Type de document : Article/Communication Auteurs : N. Konstantinos, Auteur ; A. Antonis, Auteur Année de publication : 2004 Article en page(s) : pp 3 - 9 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] analyse comparative [Termes IGN] contrôle qualité [Termes IGN] estimation statistique [Termes IGN] image Terra-ASTER [Termes IGN] modèle numérique de terrain [Termes IGN] Péloponnèse [Termes IGN] précision géométrique (imagerie) [Termes IGN] résolution multiple Résumé : (Auteur) In this paper we present the use of ASTER data for the creation of a Digital Terrain Model (DMT) of high accuracy. Using a stereo pair of ASTER satellite images with 15m resolution we created two DMTs: one with a 30m pixel size and another one with a 15m pixel size. Then we made a statistical verification of the two DTMs accuracy. We created another DTM with 30m pixel size from digitized contours of 1:50000 scale topographic maps. We first made an optical comparison of the two DTMs with 30m pixel size. Then we subtracted the two DTMs and we presented their difference. Finally, we verified the DTMs accuracy using 68 points of a well-known elevation. All the results demonstrated that DTMs derived from ASTER data have very good accuracy. Numéro de notice : A2004-231 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040408542293 Date de publication en ligne : 02/01/2008 En ligne : https://doi.org/10.1080/10106040408542293 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26758 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
059-04011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Using maximum likelihood (ML) and maximum a prior probability (MAP) in iterative self-organizing data (Isodata) / Hassan A. Karimi in Geocarto international, vol 19 n° 1 (March - May 2004)  

Public [article]  inGeocarto international > vol 19 n° 1 (March - May 2004) . - pp 29 - 36 Titre : Using maximum likelihood (ML) and maximum a prior probability (MAP) in iterative self-organizing data (Isodata) Type de document : Article/Communication Auteurs : Hassan A. Karimi, Auteur ; Jinzheng Peng, Auteur Année de publication : 2004 Article en page(s) : pp 29 - 36 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] carte de Kohonen [Termes IGN] classification non dirigée [Termes IGN] classification par maximum de vraisemblance [Termes IGN] image à très haute résolution [Termes IGN] image satellite [Termes IGN] itération Résumé : (Auteur) With the availability of high-resolution satellite imagery featuring as high as 1 meter resolution in the panchromatic mode and 3-meter resolution in the multispectral mode, there is an interest by many new commercial and public service applications such as cellular telephones coverage area design, urban/land cover planning, and real estate marketing to extract features from images automatically. To that end, the demand for unsupervised classification techniques is growing. In this paper, the Maximum Likelihood (ML) and Maximum A prior Probability (MAP) algorithms are used as decision rules to find boundaries of classes computed by the Iterative Self-Organizing Data (ISOADATA) algorithm. Different satellite images with different resolutions were used to experiment with these algorithms. The results of comparing and analyzing the algorithms revealed that MAP-ISODATA performed better than ML-ISODATA even when the same initial matrix was used. It was shown that there was no significant différence between ML-ISODATA and MAP-ISODATA in terms of accuracy. It was also realized that better results could be obtained if homogenous initialization strategies were used. Numéro de notice : A2004-232 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040408542296 Date de publication en ligne : 02/01/2008 En ligne : https://doi.org/10.1080/10106040408542296 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26759 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
059-04011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Assessing 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)  

Public [article]  inGeocarto international > vol 19 n° 1 (March - May 2004) . - pp 65 - 75 Titre : Assessing the potential of space-borne C-band SAR data for spatial soil moisture information over a large area Type de document : Article/Communication Auteurs : S.A. Romshoo, Auteur ; K. Musiake, Auteur Année de publication : 2004 Article en page(s) : pp 65 - 75 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] analyse en composantes principales [Termes IGN] humidité du sol [Termes IGN] image ERS-SAR [Termes IGN] image Radarsat [Termes IGN] modèle de diffusion du rayonnement [Termes IGN] rétrodiffusion [Termes IGN] zone humide Résumé : (Auteur) The backscattering coefficient ä from a time series of ERS-2 SAR data showed high correlation (r 2 =0.94) and high sensitivity to the observed surface soil moisture at a field scale. The observations agreed well with the simulations from the two surface scattering models tested in the study area. A single coincidence of the ERS-2 and RADARSAT missions, with two different polarizations, provided an opportunity to estimate soil moisture over a large area by inverting the Dubois model. The estimates were validated with the field observations over a small area and are in good agreement with standard error of estimate (SEE) equal to 1.01 cm3 cm-3. Furthermore, different soil moisture estimation methods were tested and compared with the observations to better understand the temporal and spatial variability of this important parameter. Soil moisture at a point was simulated using three hydrological models and compared with the radar backscattering and the point observations. There is a large variation in the responses among them. Simple statistical approaches viz., coefficient of variation and principal component analysis were used for mapping the spatial patterns of soil moisture over a large area using a time series of ERS-2 data. These simple methods helped to map areas where the moisture availability is not varying much. This information about soil moisture distribution is of vital importance to the hydrological processes especially the variable source area concept. Numéro de notice : A2004-233 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040408542300 Date de publication en ligne : 02/01/2008 En ligne : https://doi.org/10.1080/10106040408542300 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26760 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
059-04011	RAB	Revue	Centre de documentation	En réserve L003	Disponible