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Non-tidal loading of the Baltic Sea in Latvian GNSS time series / Diana Haritonova in Journal of applied geodesy, vol 15 n° 4 (October 2021)  

Public [article]  inJournal of applied geodesy > vol 15 n° 4 (October 2021) . - pp 293 - 304 Titre : Non-tidal loading of the Baltic Sea in Latvian GNSS time series Type de document : Article/Communication Auteurs : Diana Haritonova, Auteur Année de publication : 2021 Article en page(s) : pp 293 - 304 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Baltique, mer [Termes IGN] coefficient de corrélation [Termes IGN] Continuously Operating Reference Station network [Termes IGN] données GNSS [Termes IGN] effet de charge [Termes IGN] Lettonie [Termes IGN] marégraphe [Termes IGN] niveau de la mer [Termes IGN] série temporelle [Termes IGN] station de référence [Termes IGN] surcharge océanique Résumé : (auteur) The objective of this study is to investigate the effect of the Baltic Sea non-tidal loading in the territory of Latvia using observations of the GNSS continuously operating reference stations (CORS) of LatPos, EUPOS®-Riga, EPN and EstPos networks. The GNSS station daily coordinate time series obtained in a double-difference (DD) mode were used. For representation of the sea level dynamics, the Latvian tide gauge records were used. Performed correlation analysis is based on yearly data sets of these observations for the period from 2012 up to 2020. The approach discloses how the non-tidal loading can induce variations in the time series of the regional GNSS station network. This paper increases understanding of the Earth’s surface displacements occurring due to the non-tidal loading effect in Latvia, and is intended to raise the importance and necessity of improved Latvian GNSS time series by removing loading effects. Numéro de notice : A2021-750 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2021-0024 Date de publication en ligne : 23/06/2021 En ligne : https://doi.org/10.1515/jag-2021-0024 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98719 [article]

Characteristics of seasonal variations and noises of the daily double-difference and PPP solutions / Kamil Maciuk in Journal of applied geodesy, vol 15 n° 1 (January 2021)  

Public [article]  inJournal of applied geodesy > vol 15 n° 1 (January 2021) . - pp 61 - 73 Titre : Characteristics of seasonal variations and noises of the daily double-difference and PPP solutions Type de document : Article/Communication Auteurs : Kamil Maciuk, Auteur ; Inese Vārna, Auteur ; Chang Xu, Auteur Année de publication : 2021 Article en page(s) : pp 61 - 73 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bruit blanc [Termes IGN] bruit rose [Termes IGN] déformation de la croute terrestre [Termes IGN] double différence [Termes IGN] Lettonie [Termes IGN] positionnement ponctuel précis [Termes IGN] série temporelle [Termes IGN] station de référence [Termes IGN] variance de Hadamard [Termes IGN] variation saisonnière [Termes IGN] vitesse [Vedettes matières IGN] Traitement de données GNSS Résumé : (auteur) Long term GNSS observations provided by networks of the continuously operating reference stations (CORS) allow for determination of the global and local tectonic plate movements and seasonal variations. In recent years, PPP (Precise Point Positioning) technique has become increasingly popular and most likely in the future will replace relative positioning with CORS stations. In this paper, we discuss the difference of the velocity and seasonal component estimates of 25 Latvian CORS stations on the basis of daily PPP solutions from the Nevada Geodetic Laboratory and double-difference solutions from the Institute of Geodesy and Geoinformatics of the University of Latvia. Time series of each coordinate component for 9-year time period were determined by the usage of the Tsview software and seasonal existence of linear, annual, semi-annual factors and their uncertainties were determined. Breaks (e. g., antenna and receiver changes) were also taken into account. We then assessed the noise characteristics of these time series with the use of overlapping Hadamard variance (OHVAR). The result shows that OHVAR is computationally cheap, and the dominating power-law noise, including flicker and random walk. However Hadamard deviation of the PPP and double-difference solutions scatters differently for a whole year averaging time due to the different GNSS data strategies. Numéro de notice : A2021-045 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2020-0042 Date de publication en ligne : 08/12/2020 En ligne : https://doi.org/10.1515/jag-2020-0042 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96772 [article]

Consolidation of crowd-sourced geo-ragged data for parameterized travel recommendations / Ago Luberg (2021)  

Public Titre : Consolidation of crowd-sourced geo-ragged data for parameterized travel recommendations Type de document : Thèse/HDR Auteurs : Ago Luberg, Auteur ; Tanel Tammet, Directeur de thèse Editeur : Tallinn [Estonia] : Tallinn University of Technology Année de publication : 2021 Importance : 159 p. Format : 21 x 30 cm Note générale : bibliographie Dissertation accepted for the defence of the degree of Doctor of Philosophy in Computer Science Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] apprentissage automatique [Termes IGN] base de données [Termes IGN] conception orientée utilisateur [Termes IGN] données localisées des bénévoles [Termes IGN] extraction de données [Termes IGN] géoréférencement [Termes IGN] point d'intérêt [Termes IGN] Riga [Termes IGN] site wiki [Termes IGN] système de recommandation [Termes IGN] Tallinn [Termes IGN] taxinomie [Termes IGN] tourisme Résumé : (auteur) The research covered in this thesis is focused on different aspects of the task of creating automated recommendations for tourism, focusing mostly on places of interest like beautiful views, architectural landmarks, charming areas etc. A significant amount of work has been spent on designing and developing actual recommender systems - Sightsplanner, Sightsmap and the automated recommender of Visit Estonia - and their data harvesting methods in order to create a platform for showing the feasibility of the new methods designed and experimented with. The main results of our research are split between three subfields: • Knowledge engineering: we have shown how to formalize fuzzy and uncertain POI categories along with suitable ontologies and reasoner-based algorithms for object matching and score calculation in a real-life context of actual POI-s, available data and easily expressable user preferences. • Machine learning: we have designed a learnable detection system for detecting duplicate POIs from different databases, usable for cross- category, cross-language and cross-city datasets. • We show that learning on Tallinn eateries improved the algorithm parameters to such a degree that on Riga data containing also museums and galleries it gave us 98% accuracy versus 85% accuracy achieved by tuning the algorithm parameters manually. • Knowledge extraction: we have designed an algorithm for high-quality keyword extraction from short crowd-sourced POI descriptions in different languages, able to find a suitable name and to add suitable types to the POI. Our clusterization algorithm is able to merge the POIs based on the extracted data: on the Panoramio and Wikipedia data about U.K. and French locations it was able to find 56% of Wikipedia objects from the textual titles/annotations of Panoramio pictures in the area. Note de contenu : 1- Introduction 2- Related work 3- Involvement in recommender projects 4- Data acquisition and information extraction 5- Data deduplication (using machine learning) 6- Location category and name detection 7- Data storage and object score calculation 8- Conclusions 9- Future work Numéro de notice : 28600 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Thèse étrangère Note de thèse : PhD Thesis : Computer Science : Tallinn University of Technology : 2021 DOI : 10.23658/taltech.23/2021 En ligne : https://doi.org/10.23658/taltech.23/2021 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99407

Norway spruce seedlings from an Eastern Baltic provenance show tolerance to simulated drought / Roberts Matisons in Forests, vol 12 n° 1 (January 2021)  

Public [article]  inForests > vol 12 n° 1 (January 2021) . - n° 82 Titre : Norway spruce seedlings from an Eastern Baltic provenance show tolerance to simulated drought Type de document : Article/Communication Auteurs : Roberts Matisons, Auteur ; Oskars Krišāns, Auteur ; Aris Jansons, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 82 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] adaptation (biologie) [Termes IGN] analyse de sensibilité [Termes IGN] chlorophylle [Termes IGN] état du sol [Termes IGN] irrigation [Termes IGN] Lettonie [Termes IGN] photosynthèse [Termes IGN] Picea abies [Termes IGN] sécheresse [Termes IGN] stress hydrique [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) In Northern Europe, an increase in heterogeneity of summer precipitation regime will subject forests to water deficit and drought. This is particularly topical for Norway spruce (Picea abies Karst.), which is a drought sensitive, yet economically important species. Nevertheless, local populations still might be highly plastic and tolerant, supporting their commercial application. Accordingly, the tolerance of Norway spruce seedlings from an Eastern Baltic provenance (western part of Latvia) to artificial drought according to soil type was assessed in a shelter experiment. To simulate drought, seedlings were subjected to reduced amounts (0%, 25%, 50%, 75%, and 100%) of naturally occurring precipitation (irrigation intensity). Three soil types (oligotrophic mineral, mesotrophic mineral, and peat) were tested. Seedling height, chlorophyll a concentration, and fluorescence parameters were measured. Both growth and photochemical reactions were affected by the irrigation intensity, the effect of which experienced an interacted with soil type, implying complex controls of drought sensitivity. Seedlings were more sensitive to irrigation intensity on mesotrophic mineral soil, as suggested by growth and photosynthetic activity. However, the responses were nonlinear, as the highest performance (growth and fluorescence parameters) of seedlings occurred in response to intermediate drought. On peat soil, which had the highest water-bearing capacity, an inverse response to irrigation intensity was observed. In general, fluorescence parameters were more sensitive and showed more immediate reaction to soil water deficit than concentration of chlorophyll on mesotrophic mineral and peat soils, while the latter was a better indicator of seedling performance on oligotrophic soil. This indicated considerable plastic acclimation and hence tolerance of seedlings from the local Norway spruce population to drought, though drought sensitivity is age-dependent. Numéro de notice : A2021-145 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12010082 Date de publication en ligne : 14/01/2021 En ligne : https://doi.org/10.3390/f12010082 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97048 [article]

Reintroduction of the European bison (Bison bonasus) in central-eastern Europe: a case study / Cathlin M. Lord in International journal of geographical information science IJGIS, vol 34 n° 8 (August 2020)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 34 n° 8 (August 2020) . - pp 1628 - 1647 Titre : Reintroduction of the European bison (Bison bonasus) in central-eastern Europe: a case study Type de document : Article/Communication Auteurs : Cathlin M. Lord, Auteur ; Kylie P. Wirebach, Auteur ; Jennifer Tompkins, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 1628 - 1647 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] analyse multicritère [Termes IGN] analyse spatiale [Termes IGN] biodiversité [Termes IGN] combinaison linéaire ponderée [Termes IGN] écosystème [Termes IGN] Europe centrale [Termes IGN] faune [Termes IGN] habitat animal [Termes IGN] Lettonie [Termes IGN] politique de conservation (biodiversité) [Termes IGN] Pologne [Termes IGN] population animale [Termes IGN] processus de hiérarchisation analytique Résumé : (auteur) European bison (Bison bonasus), a flagship species for the burgeoning re-wildling movement, faced challenges common to large mammals globally. These include deforestation, land use conversion, poaching, and a lack of genetic diversity. Despite these limitations, organizations such as Rewilding Europe seek to reintroduce the species to its historic range. This study focused on finding suitable reintroduction locations for a population of at least 120 individuals. Through GIS-based multi-criteria decision-making using weighted linear combination and analytical hierarchy process, a model based on known bison habitat preferences, human-centered habitat constraints, and surface geography was used to identify regions large enough to accommodate a new herd. The study area included central-eastern Europe Union countries, specifically Germany, Poland, Lithuania, and Latvia. The model identified several highly suitable regions large enough to support a new herd, with the most optimal located in Poland. Highly suitable areas represented 2.7% of the study region. Relative isolation of suitable regions reinforced the challenges of promoting gene flow between reintroduced European bison herds. This model can be replicated in other conservation planning contexts, including reintroduction of large herbivores considering anthropogenic, ecological, and physical conditions. Numéro de notice : A2020-408 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2019.1672876 Date de publication en ligne : 10/10/2019 En ligne : https://doi.org/10.1080/13658816.2019.1672876 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95467 [article]

Tree cover mapping using hybrid fuzzy C-means method and multispectral satellite images / Linda Gulbe in Baltic forestry, vol 25 n° 1 ([01/02/2019])  

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Validation of medium-scale historical maps of southern Latvia for evaluation of impact of continuous forest cover on the present-day mean stand area and tree species richness / Anda Fescenko in Baltic forestry, vol 22 n° 1 ([01/02/2016])  

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State Land Service: Pillar under Latvia's E-government / Frédérique Coumans in GIM international [en ligne], vol 29 n° 10 (October 2015)

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Les industries baltes du bois en plein essor / Al Arter in Le Bois International : l'officiel du bois [édition verte], vol 2008 n° 17 (3 et 10 mai 2008)

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Geographic information and the enlargement of the European Union / Massimo Craglia (2001)

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Latvian geoid determination with mass point frequency domain inversion / K. Kukums (1993)

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Die Bestimmung des Richtungsvektors Riga-Sofia aus Beobachtungen des Satelliten "Echo 2" / K. Arnold (1971)

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Rapport de la commission permanente de phototopographie aérienne préparé pour le congrès international de géographie, Varsovie, 1934 / Commission permanente de phototopographie (1934)

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