Descripteur
Termes IGN > 1- Outils - instruments et méthodes > méthode > analyse comparative
analyse comparativeVoir aussi |
Documents disponibles dans cette catégorie (1145)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Microtopography and ecology of pit-mound structures in second-growth versus old-growth forests / Audrey Barker Plotkin in Forest ecology and management, vol 404 (15 November 2017)
[article]
Titre : Microtopography and ecology of pit-mound structures in second-growth versus old-growth forests Type de document : Article/Communication Auteurs : Audrey Barker Plotkin, Auteur ; Peter Schoonmaker, Auteur ; Bennet Leon, Auteur ; David Foster, Auteur Année de publication : 2017 Article en page(s) : pp 14 - 23 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes IGN] analyse comparative
[Termes IGN] Betula (genre)
[Termes IGN] forêt ancienne
[Termes IGN] microtopographie
[Termes IGN] richesse floristique
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] tempêteRésumé : (auteur) Pit and mound microtopography is an important structural component of most forests, influencing soil processes and habitat diversity. These features have diminished greatly in northeastern U.S. forests since European settlement, as a result of the history of repeated logging, land-clearance followed by reforestation, and the smaller size of trees (and therefore windthrow features) comprising the prevailing second-growth forests. Despite the potential importance of this region-wide shift in forest microtopography on ecosystem structure and function, the differences in pit and mound size, distribution, and longevity between second-growth and old-growth forests are unexplored. Likewise, although many studies demonstrate that mounds and/or pits are hotspots for tree regeneration there is scant information about whether location on a mound or pit affects tree survival and growth beyond the seedling stage, or whether microtopographic regeneration patterns differ in old-growth and second-growth forests.
We compare a simulated hurricane experiment initiated in 1990 in second-growth forest (the pulldown) and an old-growth forest that was blown down by a hurricane in 1938 (Pisgah) to examine differences in pit-mound microtopography and ecology between second-growth and old-growth forest. At Pisgah, fewer, larger mounds comprised a similar areal coverage as at the pulldown. Repeated measurements of individual pit-mound structures in the pulldown revealed that pit infill proceeded more rapidly than mound erosion. Mound area increased but height decreased over time as soil from the mound tops eroded and spread around the mound base. Although 40% of mounds in the pulldown were >1 m tall immediately after the manipulation (maximum of 2.9 m), after 25 years, maximum mound height was 0.9 m. In contrast, 11% of mounds at Pisgah remained >1 m tall in 1989, 50 years after blowdown. At both sites, trees, especially Betula spp., were disproportionately found on mounds. Fewer trees than expected grew in pits at Pisgah. Tree mortality was somewhat higher on mounds and pits than on other substrates. As a mechanism to increase stand-level tree diversity, windthrow may be more critical in old-growth forests, in which niches for early-mid successional species are few, than in second-growth forest, in which early-mid successional species already comprise the majority of the trees. Pit-mound structures are a diminished component of second-growth forest, and silvicultural techniques designed to restore old-growth characteristics could include measures to preserve and enhance pit-mound features, and to cultivate large-diameter trees that will eventually create the large, long-lasting pit-mounds of the future.Numéro de notice : A2017-806 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2017.08.012 En ligne : https://doi.org/10.1016/j.foreco.2017.08.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89243
in Forest ecology and management > vol 404 (15 November 2017) . - pp 14 - 23[article]Improved atmospheric correction and chlorophyll-a remote sensing models for turbid waters in a dusty environment / Maryam R. Al Shehhi in ISPRS Journal of photogrammetry and remote sensing, vol 133 (November 2017)
[article]
Titre : Improved atmospheric correction and chlorophyll-a remote sensing models for turbid waters in a dusty environment Type de document : Article/Communication Auteurs : Maryam R. Al Shehhi, Auteur ; Imen Gherboidj, Auteur ; Hosni Gherida, Auteur Année de publication : 2017 Article en page(s) : pp 46 - 60 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] Arabie
[Termes IGN] chlorophylle
[Termes IGN] correction atmosphérique
[Termes IGN] couleur de l'océan
[Termes IGN] eau de mer
[Termes IGN] image Aqua-MODIS
[Termes IGN] image Terra-MODIS
[Termes IGN] test de performance
[Termes IGN] turbidité océaniqueRésumé : (Auteur) This study presents a comprehensive assessment of the performance of the commonly used atmospheric correction models (NIR, SWIR, NIR-SWIR and FM) and ocean color products (OC3 and OC2) derived from MODIS images over the Arabian Gulf, Sea of Oman, and Arabian Sea. The considered atmospheric correction models have been used to derive MODIS normalized water-leaving radiances (nLw), which are compared to in situ water nLw(λ) data collected at different locations by Masdar Institute, United Arab of Emirates, and from AERONET-OC (the ocean color component of the Aerosol Robotic Network) database. From this comparison, the NIR model has been found to be the best performing model among the considered atmospheric correction models, which in turn shows disparity, especially at short wavelengths (400–500 nm) under high aerosol optical depth conditions (AOT (869) > 0.3) and over turbid waters. To reduce the error induced by these factors, a modified model taking into consideration the atmospheric and water turbidity conditions has been proposed. A turbidity index was used to identify the turbid water and a threshold of AOT (869) = 0.3 was used to identify the dusty atmosphere. Despite improved results in the MODIS nLw(λ) using the proposed approach, Chl-a models (OC3 and OC2) show low performance when compared to the in situ Chl-a measurements collected during several field campaigns organized by local, regional and international organizations. This discrepancy might be caused by the improper parametrization of these models or/and the improper selection of bands. Thus, an adaptive power fit algorithm (R2 = 0.95) has been proposed to improve the estimation of Chl-a concentration from 0.07 to 10 mg/m3 by using a new blue/red MODIS band ratio of (443,488)/645 instead of the default band ratio used for OC3(443,488)/547. The selection of this new band ratio (443,488)/645 has been based on using band 645 nm which has been found to represent both water turbidity and algal absorption. Numéro de notice : A2017-721 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.09.011 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.09.011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88406
in ISPRS Journal of photogrammetry and remote sensing > vol 133 (November 2017) . - pp 46 - 60[article]Réservation
Réserver ce documentExemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2017111 RAB Revue Centre de documentation En réserve L003 Disponible 081-2017112 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt 081-2017113 DEP-EXM Revue Saint-Mandé Dépôt en unité Exclu du prêt On the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation / Vegard Ophaug in Journal of geodesy, vol 91 n° 11 (November 2017)
[article]
Titre : On the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation Type de document : Article/Communication Auteurs : Vegard Ophaug, Auteur ; Christian Gerlach, Auteur Année de publication : 2017 Article en page(s) : pp 1367 - 1382 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] collocation par moindres carrés
[Termes IGN] fonction de base radiale
[Termes IGN] fonction spline
[Termes IGN] formule de Stokes
[Termes IGN] géoïde local
[Termes IGN] précision millimétriqueRésumé : (Auteur) This work is an investigation of three methods for regional geoid computation: Stokes’s formula, least-squares collocation (LSC), and spherical radial base functions (RBFs) using the spline kernel (SK). It is a first attempt to compare the three methods theoretically and numerically in a unified framework. While Stokes integration and LSC may be regarded as classic methods for regional geoid computation, RBFs may still be regarded as a modern approach. All methods are theoretically equal when applied globally, and we therefore expect them to give comparable results in regional applications. However, it has been shown by de Min (Bull Géod 69:223–232, 1995. doi:10.1007/BF00806734) that the equivalence of Stokes’s formula and LSC does not hold in regional applications without modifying the cross-covariance function. In order to make all methods comparable in regional applications, the corresponding modification has been introduced also in the SK. Ultimately, we present numerical examples comparing Stokes’s formula, LSC, and SKs in a closed-loop environment using synthetic noise-free data, to verify their equivalence. All agree on the millimeter level. Numéro de notice : A2017-707 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1030-1 En ligne : https://doi.org/10.1007/s00190-017-1030-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88088
in Journal of geodesy > vol 91 n° 11 (November 2017) . - pp 1367 - 1382[article]Precise orbit determination of the Fengyun-3C satellite using onboard GPS and BDS observations / Min Li in Journal of geodesy, vol 91 n° 11 (November 2017)
[article]
Titre : Precise orbit determination of the Fengyun-3C satellite using onboard GPS and BDS observations Type de document : Article/Communication Auteurs : Min Li, Auteur ; Wenwen Li, Auteur ; Chuang Shi, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1313 - 1327 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] analyse comparative
[Termes IGN] correction du trajet multiple
[Termes IGN] Feng-Yun-3
[Termes IGN] orbite géostationnaire
[Termes IGN] orbitographie
[Termes IGN] orbitographie par GNSS
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par GPS
[Termes IGN] précision du positionnement
[Termes IGN] satellite météorologiqueRésumé : (Auteur) The GNSS Occultation Sounder instrument onboard the Chinese meteorological satellite Fengyun-3C (FY-3C) tracks both GPS and BDS signals for orbit determination. One month’s worth of the onboard dual-frequency GPS and BDS data during March 2015 from the FY-3C satellite is analyzed in this study. The onboard BDS and GPS measurement quality is evaluated in terms of data quantity as well as code multipath error. Severe multipath errors for BDS code ranges are observed especially for high elevations for BDS medium earth orbit satellites (MEOs). The code multipath errors are estimated as piecewise linear model in 2∘×2∘ grid and applied in precise orbit determination (POD) calculations. POD of FY-3C is firstly performed with GPS data, which shows orbit consistency of approximate 2.7 cm in 3D RMS (root mean square) by overlap comparisons; the estimated orbits are then used as reference orbits for evaluating the orbit precision of GPS and BDS combined POD as well as BDS-based POD. It is indicated that inclusion of BDS geosynchronous orbit satellites (GEOs) could degrade POD precision seriously. The precisions of orbit estimates by combined POD and BDS-based POD are 3.4 and 30.1 cm in 3D RMS when GEOs are involved, respectively. However, if BDS GEOs are excluded, the combined POD can reach similar precision with respect to GPS POD, showing orbit differences about 0.8 cm, while the orbit precision of BDS-based POD can be improved to 8.4 cm. These results indicate that the POD performance with onboard BDS data alone can reach precision better than 10 cm with only five BDS inclined geosynchronous satellite orbit satellites and three MEOs. As the GNOS receiver can only track six BDS satellites for orbit positioning at its maximum channel, it can be expected that the performance of POD with onboard BDS data can be further improved if more observations are generated without such restrictions. Numéro de notice : A2017-705 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1027-9 En ligne : https://doi.org/10.1007/s00190-017-1027-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88086
in Journal of geodesy > vol 91 n° 11 (November 2017) . - pp 1313 - 1327[article]Geometric quality assessment of trajectory-generated VGI road networks based on the symmetric arc similarity / Yan Lyu in Transactions in GIS, vol 21 n° 5 (October 2017)
[article]
Titre : Geometric quality assessment of trajectory-generated VGI road networks based on the symmetric arc similarity Type de document : Article/Communication Auteurs : Yan Lyu, Auteur ; Yehua Sheng, Auteur ; Ningning Guo, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 984 - 1009 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] analyse comparative
[Termes IGN] données localisées des bénévoles
[Termes IGN] précision des données
[Termes IGN] qualité des données
[Termes IGN] réalité de terrain
[Termes IGN] réseau routier
[Termes IGN] similitudeRésumé : (Auteur) As large amounts of trajectories from a wide variety of Volunteered Geographic Information (referred to as VGI) contributors pour into the spatial database, the geometric qualities of the VGI road networks generated from these trajectories are different from the ground truth road dataset and so need to be differently assessed. To address this issue, an assessment approach based on symmetric arc similarity is proposed, and the geometric quality of a VGI road network is assessed by its conformity with the corresponding ground truth road network, the results being visualized as hierarchical thematic maps. To compute the conformity, the geometric similarity between the VGI road arc and the corresponding ground truth road arc, which is selected by the adaptive searching distance, is measured based on the symmetric arc similarity method; the geometric quality is assessed based on an assessment matrix. Also, the symmetric arc similarity method is independent of directions and with a feature of shift-independence, which is applicable to assess the geometric qualities of different VGI road networks and makes the assessment result consistent with the actual situation of the real world. The robustness and scalability of the approach are examined using VGI road networks from different sources. Numéro de notice : A2017-633 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12256 En ligne : http://dx.doi.org/10.1111/tgis.12256 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86952
in Transactions in GIS > vol 21 n° 5 (October 2017) . - pp 984 - 1009[article]Initial assessment of the COMPASS/BeiDou-3 : new-generation navigation signals / Xiaohong Zhang in Journal of geodesy, vol 91 n° 10 (October 2017)PermalinkStand-volume estimation from multi-source data for coppiced and high forest Eucalyptus spp. silvicultural systems in KwaZulu-Natal, South Africa / Timothy Dube in ISPRS Journal of photogrammetry and remote sensing, vol 132 (October 2017)PermalinkUtilizing BCF and IFC for automated dimensional compliance control / Neil Hyland in International journal of 3-D information modeling, vol 6 n° 4 (October - December 2017)PermalinkComparison of landslide susceptibility mapping based on statistical index, certainty factors, weights of evidence and evidential belief function models / Kai Cui in Geocarto international, vol 32 n° 9 (September 2017)PermalinkDocumentation of heritage buildings using close-range UAV images: dense matching issues, comparison and case studies / Arnadi Murtiyoso in Photogrammetric record, vol 32 n° 159 (September 2017)PermalinkEnseignements du test utilisateur d'une géovisualisation dynamique : des améliorations possibles pour les expériences en cartographie / Cécile Saint-Marc in Cartes & Géomatique, n° 233 (septembre - novembre 2017)PermalinkERTK: extra-wide-lane RTK of triple-frequency GNSS signals / Bofeng Li in Journal of geodesy, vol 91 n° 9 (September 2017)PermalinkFacet segmentation-based line segment extraction for large-scale point clouds / Yangbin Lin in IEEE Transactions on geoscience and remote sensing, vol 55 n° 9 (September 2017)PermalinkInvestigation of automatic feature weighting methods (Fisher, Chi-square and Relief-F) for landslide susceptibility mapping / Emrehan Kutlug Sahin in Geocarto international, vol 32 n° 9 (September 2017)PermalinkMapMosaic : dynamic layer compositing for interactive geovisualization / María-Jesús Lobo in International journal of geographical information science IJGIS, vol 31 n° 9-10 (September - October 2017)PermalinkA new GPU bundle adjustment method for large-scale data / Zhou Shunping ; Xiong Xiaodong ; Junfeng Zhu in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 9 (September 2017)PermalinkPrecision estimation of the angular resolution of terrestrial laser scanners / Xijiang Chen in Photogrammetric record, vol 32 n° 159 (September 2017)PermalinkHow Galiléo benefits high-precision RTK / Xiaoguang Luo in GPS world, vol 28 n° 8 (August 2017)PermalinkImage matching as a data source for forest inventory – Comparison of semi-global matching and next-generation automatic terrain extraction algorithms in a typical managed boreal forest environment / Mari Kukkonen in International journal of applied Earth observation and geoinformation, vol 60 (August 2017)PermalinkA relative evaluation of random forests for land cover mapping in an urban area / Di Shi in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 8 (August 2017)PermalinkTrajectory-based place-recognition for efficient large scale localization / Simon Lynen in International journal of computer vision, vol 124 n° 1 (August 2017)PermalinkAdaptive and plastic responses of Quercus petraea populations to climate across Europe / Cuauhtémoc Saenz-Romero in Global change biology, vol 23 n° 7 (July 2017)PermalinkUne chaîne de données pour évaluer la qualité des données OSM. Partie 1 : Extraction des données et description / Damien Garaud in Géomatique expert, n° 117 (juillet - août 2017)PermalinkEvaluating the performance of using PPK-GPS technique in producing topographic contour map / Ahmed El Shouny in Marine geodesy, vol 40 n° 4 (July 2017)PermalinkGold – A novel deconvolution algorithm with optimization for waveform LiDAR processing / Tan Zhou in ISPRS Journal of photogrammetry and remote sensing, vol 129 (July 2017)PermalinkImproved geometric modeling of 1960s KH-5 ARGON satellite images for regional Antarctica applications / Wenkai Ye in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 7 (July 2017)PermalinkStory Maps & Co. Un état de l’art de la cartographie des récits sur Internet / Sébastien Caquard in Mappemonde, n° 121 (juillet 2017)PermalinkAn accelerated image matching technique for UAV orthoimage registration / Chung-Hsien Tsai in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)PermalinkAutomatic illumination-invariant image-to-geometry registration in outdoor environments / Christian Kehl in Photogrammetric record, vol 32 n° 158 (June - july 2017)PermalinkCartographic analysis of transformations of the spatial structure of lands of Podgorze in Krakow in Poland in the period of 1847–2016 / Wojciech Przegon in Geodetski vestnik, vol 61 n° 2 (June - August 2017)PermalinkDevelopment and Comparison of Species Distribution Models for Forest Inventories / Óscar Rodríguez de Rivera in ISPRS International journal of geo-information, vol 6 n° 6 (June 2017)PermalinkImprovements in precise orbits of altimetry satellites and their impact on mean sea level monitoring / Sergei Rudenko in IEEE Transactions on geoscience and remote sensing, vol 55 n° 6 (June 2017)PermalinkIntegrated precipitable water from GPS observations and cimel sunphotometer measurements at CGO Belsk / Michal Kruczyk in Reports on geodesy and geoinformatics, vol 103 n° 1 (June 2017)PermalinkTM-Based SOC models augmented by auxiliary data for carbon crediting programs in semi-arid environments / Salahuddin M. Jaber in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 6 (June 2017)PermalinkUser testing of dynamic geovisualizations : lessons learned and possible improvements for cartographic experiments / Cécile Saint-Marc in International journal of cartography, vol 3 n° 1 (June 2017)PermalinkBaltic sea ice concentration estimation using SENTINEL-1 SAR and AMSR2 microwave radiometer data / Juha Karvonen in IEEE Transactions on geoscience and remote sensing, vol 55 n° 5 (May 2017)PermalinkEvaluation of the range accuracy and the radiometric calibration of multiple terrestrial laser scanning instruments for data interoperability / Kim Calders in IEEE Transactions on geoscience and remote sensing, vol 55 n° 5 (May 2017)PermalinkModeling Mediterranean forest structure using airborne laser scanning data / Francesca Bottalico in International journal of applied Earth observation and geoinformation, vol 57 (May 2017)PermalinkUrban land use/land cover discrimination using image-based reflectance calibration methods for hyperspectral data / Shailesh S. Deshpande in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 5 (May 2017)PermalinkAn examination of the Galileo NeQuick model: comparison with GPS and JASON TEC / Ningbo Wang in GPS solutions, vol 21 n° 2 (April 2017)PermalinkA GIS-based comparative study of Dempster-Shafer, logistic regression and artificial neural network models for landslide susceptibility mapping / Wei Chen in Geocarto international, vol 32 n° 4 (April 2017)PermalinkEstimation and analysis of Galileo differential code biases / Min Li in Journal of geodesy, vol 91 n° 3 (March 2017)PermalinkA participatory framework for developing public participation GIS solutions to improve resource management systems / Nagesh Kolagani in International journal of geographical information science IJGIS, vol 31 n° 3-4 (March-April 2017)PermalinkComparison of belief propagation and graph-cut approaches for contextual classification of 3D LIDAR point cloud data / Loïc Landrieu (2017)PermalinkDevelopment of a sampling protocol for monitoring snow melt using photogrammetry / Guillaume Sutter (2017)PermalinkDifferences between mean tide level and mean sea level / Philip L. Woodworth in Journal of geodesy, vol 91 n° 1 (January 2017)PermalinkDonnées 3D et SIG en open source / Anonyme in Géomatique expert, n° 114 (janvier - février 2017)PermalinkGPS/BDS short-term ISB modelling and prediction / Nan Jiang in GPS solutions, vol 21 n° 1 (January 2017)PermalinkModèle numérique de terrain par drone photogrammétrique sur le littoral de l’île d’Oléron / Steven Humbert (2017)PermalinkLa nécessaire cohérence entre Copernicus et les infrastructures nationales INSPIRE [diaporama] / François Chirie (2017)Permalink