Descripteur
Documents disponibles dans cette catégorie (1828)
![](./images/expand_all.gif)
![](./images/collapse_all.gif)
Etendre la recherche sur niveau(x) vers le bas
Estimation of vegetation parameter for modelling soil erosion using linear spectral mixture analysis of Landsat ETM data / A.M. DE Asis in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 4 (September 2007)
![]()
[article]
Titre : Estimation of vegetation parameter for modelling soil erosion using linear spectral mixture analysis of Landsat ETM data Type de document : Article/Communication Auteurs : A.M. DE Asis, Auteur ; K. Omasa, Auteur Année de publication : 2007 Article en page(s) : pp 309 - 324 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse linéaire des mélanges spectraux
[Termes IGN] classification pixellaire
[Termes IGN] couvert végétal
[Termes IGN] données de terrain
[Termes IGN] érosion
[Termes IGN] estimation statistique
[Termes IGN] image Landsat-ETM+
[Termes IGN] image Quickbird
[Termes IGN] modèle physique
[Termes IGN] modèle RUSLERésumé : (Auteur) Soil conservation planning often requires estimates of soil erosion at a catchment or regional scale. Predictive models such as Universal Soil Loss Equation (USLE) and its subsequent Revised Universal Soil Loss Equation (RUSLE) are useful tools to generate the quantitative estimates necessary for designing sound conservation measures. However, large-scale soil erosion model-factor parameterization and quantification is difficult due to the costs, labor and time involved. Among the soil erosion parameters, the vegetative cover or C factor has been one of the most difficult to estimate over broad geographic areas. The C factor represents the effects of vegetation canopy and ground covers in reducing soil loss. Traditional methods for the extraction of vegetation information from remote sensing data such as classification techniques and vegetation indices were found to be inaccurate. Thus, this study presents a new approach based on Spectral Mixture Analysis (SMA) of Landsat ETM data to map the C factor for use in the modeling of soil erosion. A desirable feature of SMA is that it estimates the fractional abundance of ground cover and bare soils simultaneously, which is appropriate for soil erosion analysis. Hence, we estimated the C factor by utilizing the results of SMA on a pixel-by-pixel basis. We specifically used a linear SMA (LSMA) model and performed a minimum noise fraction (MNF) transformation and pixel purity index (PPI) on Landsat ETM image to derive the proportion of ground cover (vegetation and non-photosynthetic materials) and bare soil within a pixel. The end-members were selected based on the purest pixels found using PPI with reference to very high-resolution QuickBird image and actual field data. Results showed that the C factor value estimated using LSMA correlated strongly with the values measured in the field. The correlation coefficient (r) obtained was 0.94. A comparative analysis between NDVI- and LSMA-derived C factors also proved that the latter produced a more detailed spatial variability, as well as generated more accurate erosion estimates when used as input to RUSLE model. The QuickBird image coupled with field data was used in the validation of results. Copyright ISPRS Numéro de notice : A2007-430 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.05.013 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.05.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28793
in ISPRS Journal of photogrammetry and remote sensing > vol 62 n° 4 (September 2007) . - pp 309 - 324[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-07061 SL Revue Centre de documentation Revues en salle Disponible Filling the voids in the SRTM elevation model: a tin-based delta surface approach / E. Luedeling in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 4 (September 2007)
![]()
[article]
Titre : Filling the voids in the SRTM elevation model: a tin-based delta surface approach Type de document : Article/Communication Auteurs : E. Luedeling, Auteur ; S. Siebert, Auteur ; A. Buerkert, Auteur Année de publication : 2007 Article en page(s) : pp 283 - 294 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] altitude
[Termes IGN] analyse comparative
[Termes IGN] erreur systématique
[Termes IGN] fusion de données
[Termes IGN] interpolation spatiale
[Termes IGN] MNS SRTM
[Termes IGN] modèle numérique de surface
[Termes IGN] montagne
[Termes IGN] Oman
[Termes IGN] positionnement par GPS
[Termes IGN] Triangulated Irregular NetworkRésumé : (Auteur) The Digital Elevation Model (DEM) derived from NASA's Shuttle Radar Topography Mission is the most accurate near-global elevation model that is publicly available. However, it contains many data voids, mostly in mountainous terrain. This problem is particularly severe in the rugged Oman Mountains. This study presents a method to fill these voids using a fill surface derived from Russian military maps. For this we developed a new method, which is based on Triangular Irregular Networks (TINs). For each void, we extracted points around the edge of the void from the SRTM DEM and the fill surface. TINs were calculated from these points and converted to a base surface for each dataset. The fill base surface was subtracted from the fill surface, and the result added to the SRTM base surface. The fill surface could then seamlessly be merged with the SRTM DEM. For validation, we compared the resulting DEM to the original SRTM surface, to the fill DEM and to a surface calculated by the International Center for Tropical Agriculture (CIAT) from the SRTM data. We calculated the differences between measured GPS positions and the respective surfaces for 187,500 points throughout the mountain range (?GPS). Comparison of the means and standard deviations of these values showed that for the void areas, the fill surface was most accurate, with a standard deviation of the ?GPS from the mean ?GPS of 69 m, and only little accuracy was lost by merging it to the SRTM surface (standard deviation of 76 m). The CIAT model was much less accurate in these areas (standard deviation of 128 m). The results show that our method is capable of transferring the relative vertical accuracy of a fill surface to the void areas in the SRTM model, without introducing uncertainties about the absolute elevation of the fill surface. It is well suited for datasets with varying altitude biases, which is a common problem of older topographic information. Copyright ISPRS Numéro de notice : A2007-429 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.05.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.05.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28792
in ISPRS Journal of photogrammetry and remote sensing > vol 62 n° 4 (September 2007) . - pp 283 - 294[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-07061 SL Revue Centre de documentation Revues en salle Disponible Least-squares prediction in linear models with integer unknowns / Peter J.G. Teunissen in Journal of geodesy, vol 81 n° 9 (September 2007)
![]()
[article]
Titre : Least-squares prediction in linear models with integer unknowns Type de document : Article/Communication Auteurs : Peter J.G. Teunissen, Auteur Année de publication : 2007 Article en page(s) : pp 565 - 579 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] collocation par moindres carrés
[Termes IGN] estimation statistique
[Termes IGN] modèle linéaireRésumé : (Auteur) The prediction of spatially and/or temporal varying variates based on observations of these variates at some locations in space and/or instances in time, is an important topic in the various spatial and Earth sciences disciplines. This topic has been extensively studied, albeit under different names. The underlying model used is often of the trend-signal-noise type. This model is quite general and it encompasses many of the conceivable measurements. However, the methods of prediction based on these models have only been developed for the case the trend parameters are real-valued. In the present contribution we generalize the theory of least-squares prediction by permitting some or all of the trend parameters to be integer valued. We derive the solution for least-squares prediction in linear models with integer unknowns and show how it compares to the solution of ordinary least-squares prediction. We also study the probabilistic properties of the associated estimation and prediction errors. The probability density functions of these errors are derived and it is shown how they are driven by the probability mass functions of the integer estimators. Finally, we show how these multimodal distributions can be used for constructing confidence regions and for cross-validation purposes aimed at testing the validity of the underlying model. Copyright Springer Numéro de notice : A2007-390 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0138-0 En ligne : https://doi.org/10.1007/s00190-007-0138-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28753
in Journal of geodesy > vol 81 n° 9 (September 2007) . - pp 565 - 579[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 266-07071 RAB Revue Centre de documentation En réserve L003 Disponible 266-07072 RAB Revue Centre de documentation En réserve L003 Disponible Map projections minimizing distance errors / J.R. Gott in Cartographica, vol 42 n° 3 (September 2007)
![]()
[article]
Titre : Map projections minimizing distance errors Type de document : Article/Communication Auteurs : J.R. Gott, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 219 - 234 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Projections
[Termes IGN] analyse comparative
[Termes IGN] erreur moyenne quadratique
[Termes IGN] Lune
[Termes IGN] Mars (planète)
[Termes IGN] planète
[Termes IGN] projection
[Termes IGN] projection azimutale
[Termes IGN] projection équidistanteRésumé : (Auteur) Maps convey important information about distances between pairs of points. It is therefore desirable to minimize the errors made in representing distances between pairs of points on maps. Since it is just as bad to have two points on the map at twice their proper separation as to have them at half their proper separation, it is the root-mean-square (rms) logarithmic distance between random points in the mapped region that we will minimize. The best previously known projection of the entire sphere for distances is the Lambert equal-area azimuthal, with an rms logarithmic distance error of ó = 0.343. By way of comparison, the Mercator projection has ó = 0.444 and the Mollweide, ó = 0.390. We present three new projections - the Gott equal-area elliptical, with perfect shapes on the central meridian; the Gott-Mugnolo equal-area elliptical; and the Gott-Mugnolo azimuthal, with rms logarithmic distance errors of ó 0.365, ó = 0.348, and ó = 0.341 respectively - that improve on previous projections of their type. The Gott-Mugnolo azimuthal projection has the lowest distance errors of any map and is produced by a new technique using "forces" between pairs of points on a map, which make the points move so as to minimize ó. The Gott equal-area elliptical projection produces a particularly attractive map of Mars, and the Gott-Mugnolo azimuthal projection produces an interesting map of the Moon, both of which we also show. Copyright University of Toronto Press Numéro de notice : A2007-489 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : 10.3138/carto.42.3.219 En ligne : https://doi.org/10.3138/carto.42.3.219 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28852
in Cartographica > vol 42 n° 3 (September 2007) . - pp 219 - 234[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 031-07031 RAB Revue Centre de documentation En réserve L003 Disponible Efficient multiresolution spatial predictions for large data arrays / Magnussen, Steen in Remote sensing of environment, vol 109 n° 4 (30 August 2007)
![]()
[article]
Titre : Efficient multiresolution spatial predictions for large data arrays Type de document : Article/Communication Auteurs : Magnussen, Steen, Auteur ; Erik Naesset, Auteur ; Michael A. Wulder, Auteur Année de publication : 2007 Article en page(s) : pp 451 - 463 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] erreur moyenne quadratique
[Termes IGN] image multi sources
[Termes IGN] interpolation
[Termes IGN] interpolation inversement proportionnelle à la distance
[Termes IGN] lissage de données
[Termes IGN] modèle numérique de terrain
[Termes IGN] résolution multiple
[Termes IGN] signal laserRésumé : (Auteur) Imputations of missing values and optimal smoothing with massive data arrays poses a computational challenge since ordinary kriging becomes infeasible. Imputation and smoothing with standard algorithms like inverse distance weighted nearest neighbour interpolation (IDW) and interpolation on triangulated irregular networks (TIN/IP) fail to incorporate the spatial structure and ignore information beyond the neighbourhood. Multiresolution spatial models (MRSM) or approximate kriging methods adapted to handling massive data sets can be expected to do better than IDW and TIN/IP in terms of mean square errors of prediction (MSEP). We illustrate a MRSM that is efficient, computationally fast, and easy to implement. In two forestry examples with imputation of LiDAR range values the MRSM achieved a lower MSEP than IDW, TIN/IP, and fixed ranked kriging. MRSM appear as especially attractive for the construction of a DTM from last return LiDAR pulses. A third example demonstrates MRSM for efficient smoothing. Numéro de notice : A2007-319 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2007.01.018 En ligne : https://doi.org/10.1016/j.rse.2007.01.018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28682
in Remote sensing of environment > vol 109 n° 4 (30 August 2007) . - pp 451 - 463[article]Optimizing image resolution to maximize the accuracy of hard classification / K.R. Mccloy in Photogrammetric Engineering & Remote Sensing, PERS, vol 73 n° 8 (August 2007)
PermalinkSpatio-temporal urban landscape change analysis using the Markov chain model and a modified genetic algorithm / J. Tang in International Journal of Remote Sensing IJRS, vol 28 n°15-16 (August 2007)
PermalinkAccuracy assessment of digital elevation models using a non-parametric approach / F. Aguilar in International journal of geographical information science IJGIS, vol 21 n° 6-7 (july 2007)
PermalinkSpatial aspects of MRSA epidemiology: a case study using stochastic simulation, kernel estimation and SaTScan / Lucy Bastin in International journal of geographical information science IJGIS, vol 21 n° 6-7 (july 2007)
PermalinkUse of TRMM in determining the climatic characteristics of rainfall over Bangladesh / M.N. Islam in Remote sensing of environment, vol 108 n° 3 (15/06/2007)
PermalinkÉvaluer les choix d'itinéraires pédestres en milieu urbain / A. Piombini in Revue internationale de géomatique, vol 17 n° 2 (juin – août 2007)
PermalinkGeometric consistency and stability of consumer-grade digital cameras for accurate spatial measurement / R. Wackrow in Photogrammetric record, vol 22 n° 118 (June - August 2007)
PermalinkIndirect approach to invariant point determination for SLR and VLBI systems: an assessment / John Dawson in Journal of geodesy, vol 81 n° 6-8 (June - August 2007)
PermalinkStability of VLBI, SLR, DORIS, and GPS positioning / Martine Feissel-Vernier in Earth, Planets and Space, vol 59 n° 6 (June 2007)
![]()
PermalinkDORIS satellite phase center determination and consequences on the derived scale of the Terrestrial Reference Frame / Pascal Willis in Advances in space research, vol 39 n° 10 (May 2007)
PermalinkInfluence of ambiguity precision on the success rate of GNSS integer ambiguity bootstrapping / Peter J.G. Teunissen in Journal of geodesy, vol 81 n° 5 (May 2007)
PermalinkInteractive visualization of uncertain spatial and spatio-temporal data under different scenarios: an air quality example / Edzer J. Pebesma in International journal of geographical information science IJGIS, vol 21 n° 5 (may 2007)
PermalinkModelling landscape dynamics with Python / D. Karssenberg in International journal of geographical information science IJGIS, vol 21 n° 5 (may 2007)
PermalinkA probabilistic framework for representing and simulating uncertain environmental variables / Gerard B.M. Heuvelink in International journal of geographical information science IJGIS, vol 21 n° 5 (may 2007)
PermalinkThe topographic bias by analytical continuation in physical geodesy / Lard Erik Sjöberg in Journal of geodesy, vol 81 n° 5 (May 2007)
PermalinkAnalysis of DORIS range-rate residuals for TOPEX/Poseidon, Jason, Envisat and SPOT / Eelco Doornbos in Acta Astronautica, vol 60 n° 8-9 (April - May 2007)
PermalinkA comparison of four common atmospheric correction methods / A.S. Mahiny in Photogrammetric Engineering & Remote Sensing, PERS, vol 73 n° 4 (April 2007)
PermalinkHigher order ionospheric effects in precise GNSS positioning / M. Mainul Hoque in Journal of geodesy, vol 81 n° 4 (April 2007)
PermalinkSemantic-sensitive satellite image retrieval / Y. Li in IEEE Transactions on geoscience and remote sensing, vol 45 n° 4 (April 2007)
PermalinkContribution of ionospheric irregularities to the error of dual-frequency GNSS positioning / B.C. Kim in Journal of geodesy, vol 81 n° 3 (March 2007)
Permalink