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Least squares support vector machine model for coordinate transformation / Yao Yevenyo Ziggah in Geodesy and cartography, vol 45 n° 1 (2019)
[article]
Titre : Least squares support vector machine model for coordinate transformation Type de document : Article/Communication Auteurs : Yao Yevenyo Ziggah, Auteur Année de publication : 2019 Article en page(s) : pp 16 - 27 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] Ghana
[Termes IGN] méthode des moindres carrés
[Termes IGN] projection conforme
[Termes IGN] résidu
[Termes IGN] séparateur à vaste marge
[Termes IGN] transformation affine
[Termes IGN] transformation de coordonnéesRésumé : (auteur) In coordinate transformation, the main purpose is to provide a mathematical relationship between coordinates related to different geodetic reference frames. This gives the geospatial professionals the opportunity to link different datums together. Review of previous studies indicates that empirical and soft computing models have been proposed in recent times for coordinate transformation. The main aim of this study is to present the applicability and performance of Least Squares Support Vector Machine (LS-SVM) which is an extension of the Support Vector Machine (SVM) for coordinate transformation. For comparison purpose, the SVM and the widely used Backpropagation Neural Network (BPNN), Radial Basis Function Neural Network (RBFNN), 2D conformal and affine methods were also employed. To assess how well the transformation results fit the observed data, the root mean square of the residual horizontal distances and standard deviation were used. From the results obtained, the LS-SVM and RBFNN had comparable results and were better than the other methods. The overall statistical findings produced by LS-SVM met the accuracy requirement for cadastral surveying applications in Ghana. To this end, the proposed LS-SVM is known to possess promising predictive capabilities and could efficiently be used as a supplementary technique for coordinate transformation. Numéro de notice : A2019-482 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.3846/gac.2019.6053 Date de publication en ligne : 17/04/2019 En ligne : https://doi.org/10.3846/gac.2019.6053 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93629
in Geodesy and cartography > vol 45 n° 1 (2019) . - pp 16 - 27[article]Monitoring crops water needs at high spatio-temporal resolution by synergy of optical / thermal and radar observations / Abdelhakim Amazirh (2019)
Titre : Monitoring crops water needs at high spatio-temporal resolution by synergy of optical / thermal and radar observations Type de document : Thèse/HDR Auteurs : Abdelhakim Amazirh, Auteur ; Abdelghani Chehbouni, Directeur de thèse ; Salah Er-Raki, Auteur Editeur : Toulouse : Université de Toulouse 3 Paul Sabatier Année de publication : 2019 Importance : 240 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse en vue de l’obtention du Doctorat de l'Université de Toulouse, Spécialité : Surfaces et Interfaces Continentales, HydrologieLangues : Français (fre) Descripteur : [Vedettes matières IGN] Traitement d'image mixte
[Termes IGN] évapotranspiration
[Termes IGN] gestion de l'eau
[Termes IGN] humidité du sol
[Termes IGN] image Landsat
[Termes IGN] image Landsat-8
[Termes IGN] image multibande
[Termes IGN] image optique
[Termes IGN] image radar
[Termes IGN] image Sentinel-SAR
[Termes IGN] image Terra-MODIS
[Termes IGN] image thermique
[Termes IGN] indice de végétation
[Termes IGN] Marrakech
[Termes IGN] modèle de transfert radiatif
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] parcelle agricole
[Termes IGN] ressources en eau
[Termes IGN] stress hydrique
[Termes IGN] température de surface
[Termes IGN] zone semi-arideIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Optimizing water management in agriculture is essential over semi-arid areas in order to preserve water resources which are already low and erratic due to human actions and climate change. This thesis aims to use the synergy of multispectral remote sensing observations (radar, optical and thermal data) for high spatio-temporal resolution monitoring of crops water needs. In this context, different approaches using various sensors (Landsat-7/8, Sentinel-1 and MODIS) have been developed to provide information on the crop Soil Moisture (SM) and water stress at a spatio-temporal scale relevant to irrigation management. This work fits well the REC "Root zone soil moisture Estimates at the daily and agricultural parcel scales for Crop irrigation management and water use impact: a multi-sensor remote sensing approach" (http://rec.isardsat.com/) project objectives, which aim to estimate the Root Zone Soil Moisture (RZSM) for optimizing the management of irrigation water. Innovative and promising approaches are set up to estimate evapotranspiration (ET), RZSM, land surface temperature (LST) and vegetation water stress through SM indices derived from multispectral observations with high spatio-temporal resolution. The proposed methodologies rely on image-based methods, radiative transfer modelling and water and energy balance modelling and are applied in a semi-arid climate region (central Morocco). In the frame of my PhD thesis, three axes have been investigated. In the first axis, a Landsat LST-derived RZSM index is used to estimate the ET over wheat parcels and bare soil. The ET modelling estimation is explored using a modified Penman-Monteith equation obtained by introducing a simple empirical relationship between surface resistance (rc) and a RZSM index. The later is estimated from Landsat-derived land surface temperature (LST) combined with the LST endmembers (in wet and dry conditions) simulated by a surface energy balance model driven by meteorological forcing and Landsat-derived fractional vegetation cover. The investigated method is calibrated and validated over two wheat parcels located in the same area near Marrakech City in Morocco. In the next axis, a method to retrieve near surface (0-5 cm) SM at high spatial and temporal resolution is developed from a synergy between radar (Sentinel-1) and thermal (Landsat) data and by using a soil energy balance model. The developed approach is validated over bare soil agricultural fields and gives an accurate estimates of near surface SM with a root mean square difference compared to in situ SM equal to 0.03 m3 m-3. In the final axis a new method is developed to disaggregate the 1 km resolution MODIS LST at 100 m resolution by integrating the near surface SM derived from Sentinel-1 radar data and the optical-vegetation index derived from Landsat observations. The new algorithm including the S-1 backscatter as input to the disaggregation, produces more stable and robust results during the selected year. Where, 3.35 °C and 0.75 were the lowest RMSE and the highest correlation coefficient assessed using the new algorithm. Note de contenu : General Introduction
1- Bibliographic synthesis
2- Data & study sites description
3- Models & methods
4- Results & discussions
Conclusions and perspectivesNuméro de notice : 25694 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Surfaces et Interfaces Continentales, Hydrologie : Toulouse 3 : 2019 Organisme de stage : Centre d'Etudes Spatiales de la Biosphère CESBIO nature-HAL : Thèse DOI : sans En ligne : http://thesesups.ups-tlse.fr/4412/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94759
Titre : Multifunctional land uses in Africa : Sustainable food security solutions Type de document : Monographie Auteurs : Elisabeth Simelton, Éditeur scientifique ; Madelene Ostwald, Éditeur scientifique Editeur : Londres : Routledge Année de publication : 2019 Importance : 176 p. ISBN/ISSN/EAN : 978-0-367-24644-0 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Agriculture
[Termes IGN] Afrique (géographie politique)
[Termes IGN] agroforesterie
[Termes IGN] alimentation
[Termes IGN] aquaculture
[Termes IGN] changement climatique
[Termes IGN] changement d'utilisation du sol
[Termes IGN] développement durable
[Termes IGN] gestion de l'eau
[Termes IGN] ressources naturelles
[Termes IGN] sécurité alimentaire
[Termes IGN] surface cultivéeRésumé : (éditeur) This book presents contemporary case studies of land use, management practices, and innovation in Africa with a view to exploring how multifunctional land uses can alleviate food insecurity and poverty. Food security and livelihoods in Africa face multiple challenges in the form of feeding a growing population on declining land areas under the impacts of climate change. The overall question is what kind of farming systems can provide resilient livelihoods? This volume presents a selection of existing farming systems that demonstrate how more efficient use of land and natural resources, labour and other inputs can have positive effects on household food security and livelihoods. It examines how aquaculture, integrated water management, peri-urban farming systems, climate-smart agriculture practices and parkland agroforestry contribute multiple benefits. Drawing on case studies from Kenya, Ethiopia, Nigeria and Burkina Faso, contributed by young African scientists, this book provides a unique perspective on multifunctional land use in Africa and illustrates how non-conventional uses can be profitable while promoting social and environmental sustainability. Tapping into the global discussion on land scarcity and linking food security to existing land use change processes, this volume will stimulate readers looking for diversified land uses that are compatible with both household and national food security ambitions. This book will be of great interest to students and scholars of African development, agriculture, food security, land use and environmental management, as well as sustainable development more generally, in addition to policymakers and practitioners working in these areas. Note de contenu : 1- Multifunctional land-use systems – a solution for food security in Africa?
2- Nigerian climate-smart agriculture practices with scaling potential
3- Treating shea trees as crops improves women’s livelihoods in Burkina Faso
4- Economic benefits from cassava in peri-urban multiple-cropping systems in Nigeria
5- Integrated aquaculture
6- What integrated watershed management can deliver for the environment and livelihoods
7- Smallholder maize-based systems
8- Multifunctional land-use practices in AfricaNuméro de notice : 25850 Affiliation des auteurs : non IGN Nature : Monographie DOI : sans En ligne : https://www.taylorfrancis.com/books/e/9780429283666 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95440 Rattachement ITRF à Libreville / Thomas Donal (2019)
Titre : Rattachement ITRF à Libreville Type de document : Rapport Auteurs : Thomas Donal, Auteur Mention d'édition : version 1 Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2019 Collection : Documents techniques du SGM num. 600 82 8645 Importance : 56 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] Libreville (Gabon)
[Termes IGN] rattachement de station
[Termes IGN] station DORIS
[Termes IGN] station GNSS
[Termes IGN] station permanenteRésumé : (auteur) La réalisation ITRF2014 (dernière en date) de l’International Terrestrial Reference System calculée par le Laboratoire de Recherche en Géodésie de l’IGN est le résultat de la combinaison des référentiels terrestres issus des quatre techniques de géodésie spatiale (c’est à dire DORIS, GNSS, SLR et VLBI). Pour réaliser un repère unique, un moyen consiste à ajouter dans la combinaison les résultats de rattachements sur des sites co-localisés. La station de poursuite Ariane à Libreville au Gabon dispose d'une station DORIS et d’une station GNSS permanente intégrée à l’IGS. Le présent rapport décrit le rattachement de précision réalisé sur ce site en août 2019. Note de contenu : 1- Introduction
2- Co-location site description
3- Site survey description
4- Computation
5- Results
6- AppendixesNuméro de notice : 28542 Affiliation des auteurs : IGN (2012-2019) Thématique : POSITIONNEMENT Nature : Rapport de mission nature-HAL : Rapport Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97403 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 28542-01 7D Livre SGM K001 Exclu du prêt Assessing the structural differences between tropical forest types using Terrestrial Laser Scanning / Mathieu Decuyper in Forest ecology and management, vol 429 (1 December 2018)
[article]
Titre : Assessing the structural differences between tropical forest types using Terrestrial Laser Scanning Type de document : Article/Communication Auteurs : Mathieu Decuyper, Auteur ; Kalkidan Ayele Mulatu, Auteur ; Benjamin Brede, Auteur ; Kim Calders, Auteur ; John Armston, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 327 - 335 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] canopée
[Termes IGN] Coffea (genre)
[Termes IGN] Coffea arabica
[Termes IGN] données hétérogènes
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Ethiopie
[Termes IGN] forêt tropicale
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] sylvopastoralismeRésumé : (Auteur) Increasing anthropogenic pressure leads to loss of habitat through deforestation and degradation in tropical forests. While deforestation can be monitored relatively easily, forest management practices are often subtle processes, that are difficult to capture with for example satellite monitoring. Conventional measurements are well established and can be useful for management decisions, but it is believed that Terrestrial Laser Scanning (TLS) has a role in quantitative monitoring and continuous improvement of methods. In this study we used a combination of TLS and conventional forest inventory measures to estimate forest structural parameters in four different forest types in a tropical montane cloud forest in Kafa, Ethiopia. Here, the four forest types (intact forest, coffee forest, silvopasture, and plantations) are a result of specific management practices (e.g. clearance of understory in coffee forest), and not different forest communities or tree types. Both conventional and TLS derived parameters confirmed our assumptions that intact forest had the highest biomass, silvopasture had the largest canopy gaps, and plantations had the lowest canopy openness. Contrary to our expectations, coffee forest had higher canopy openness and similar biomass as silvopasture, indicating a significant loss of forest structure. The 3D vegetation structure (PAVD – Plant area vegetation density) was different between the forest types with the highest PAVD in intact forest and plantation canopy. Silvopasture was characterised by a low canopy but high understorey PAVD, indicating regeneration of the vegetation and infrequent fuelwood collection and/or non-intensive grazing. Coffee forest canopy had low PAVD, indicating that many trees had been removed, despite coffee needing canopy shade. These findings may advocate for more tangible criteria such as canopy openness thresholds in sustainable coffee certification schemes. TLS as tool for monitoring forest structure in plots with different forest types shows potential as it can capture the 3D position of the vegetation volume and open spaces at all heights in the forest. To quantify changes in different forest types, consistent monitoring of 3D structure is needed and here TLS is an add-on or an alternative to conventional forest structure monitoring. However, for the tropics, TLS-based automated segmentation of trees to derive DBH and biomass is not widely operational yet, nor is species richness determination in forest monitoring. Integration of data sources is needed to fully understand forest structural diversity and implications of forest management practices on different forest types. Numéro de notice : A2018-467 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.foreco.2018.07.032 Date de publication en ligne : 23/07/2018 En ligne : https://doi.org/10.1016/j.foreco.2018.07.032 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91146
in Forest ecology and management > vol 429 (1 December 2018) . - pp 327 - 335[article]Enhanced local ionosphere model for multi-constellations single frequency precise point positioning applications: Egyptian case study / Emad El Manaily in Artificial satellites, vol 53 n° 4 (December 2018)PermalinkEtude de faisabilité et choix optimal d'une station RIMS d'EGNOS en Algérie / Tabti Lahouaria in XYZ, n° 157 (décembre 2018 - février 2019)PermalinkCartographie des forêts humides dans la région d’El Kala (Algérie) à l’aide des outils d’observation de la Terre / Asma Kahli in Revue d'écologie, vol 73 n° 4 (octobre - décembre 2018)PermalinkA deep learning approach to DTM extraction from imagery using rule-based training labels / Caroline M. Gevaert in ISPRS Journal of photogrammetry and remote sensing, vol 142 (August 2018)PermalinkSoil moisture estimation in Ferlo region (Senegal) using radar (ENVISAT/ASAR) and optical (SPOT/VEGETATION) data / Gayane Faye in The Egyptian Journal of Remote Sensing and Space Science, Vol. 21 suppl.1 (juillet 2018)PermalinkUsing UAVs for map creation and updating: A case study in Rwanda / Mila Koeva in Survey review, vol 50 n° 361 (July 2018)PermalinkCartographie pour la réflexion sur un périmètre à irriguer dans le Sud Kivu / Anne Girardin in XYZ, n° 155 (juin - août 2018)PermalinkExtension de fuseau de la projection de Mercator Transverse : Application au réseau géodésique primordial Algérien / Bachir Gourine in XYZ, n° 155 (juin - août 2018)PermalinkUsing kites for 3-D mapping of gullies at decimetre-resolution over several square kilometres: a case study on the Kamech catchment, Tunisia / Denis Feurer in Natural Hazards and Earth System Sciences, vol 18 n° 6 ([01/06/2018])PermalinkUsing terrestrial laser scanning data to estimate large tropical trees biomass and calibrate allometric models: A comparison with traditional destructive approach / Stéphane Momo Takoudjou in Methods in ecology and evolution, vol 9 n° 4 (April 2018)Permalink