Sökning: "global vertical datum"

Hittade 5 avhandlingar innehållade orden global vertical datum.

1. 1. Study on the Earth’s Surface Mass Variations using Satellite Gravimetry Observations

   Författare :Hadi Amin; Mohammad Bagherbandi; Lars Sjöberg; Faramarz Nilfouroushan; Martin Horwath; Högskolan i Gävle; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geodetic reference system; geoid potential; global vertical datum; climate change; global warming; mass change; ice melting; sea-level change; remote sensing; satellite gravimetry; geodetiska referenssystem; geopotential; globala vertikala datum; klimatförändring; global uppvärmning; massförändring; issmältning; havsnivåförändring; fjärranalys; satellitgravimetri;

   Sammanfattning : Our complex planet is continuously undergoing temporal and spatial changes. In this context, ongoing processes in the Earth subsystems (geosphere, biosphere, cryosphere, hydrosphere, and atmosphere) cause changes in the gravity field of the Earth across a wide range of temporal and spatial scales. LÄS MER

3. 2. A height datum for Uganda based on a gravimetric quasigeoid model and GNSS/levelling

   Författare :Ronald Ssengendo; Lars Sjoberg; Anthony Gidudu; Hossein Nahavandchi; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geoid model; GNSS levelling; KTH method; Uganda; Uganda Vertical Network; Quasigeoid model; Geodesy and Geoinformatics; Geodesi och geoinformatik;

   Sammanfattning : This study is devoted to the determination of a high resolution gravimetric geoid model for Uganda based on the optimal combination of terrestrial and satellite gravity anomalies using the method of Least Squares Modification of Stokes’ formula with additive corrections. Specifically the study investigates the current status of the existing Uganda Vertical Network relative to the requirements of a modern height datum and includes a detailed evaluation and validation of terrestrial gravity data, several digital elevation models and some recent global geopotential models. LÄS MER

4. 3. Least squares modification of Stokes formula with application to the Estonian geoid

   Författare :Artu Ellmann; KTH; []
   Nyckelord :geoid; stokes formula; least sequares modification; total topographic correction; total atmospheric correction; gps levelling;

   Sammanfattning : Many applications in geodesy,geophysics and engineering require physically defined heightsrelated to an equipotential surface of the Earth, thegeoid.During the last two decades theincreased need for refined geoid models has been driven by thedemands of users of GPS, who nowadays must transformGPS-derived geodetic heights into orthometric heights, makingthem compatible with the local vertical datum. LÄS MER

5. 4. Supervised and Unsupervised Deep Learning Models for Flood Detection

   Författare :Ritu Yadav; Yifang Ban; Andrea Nascetti; Nicolas Audebert; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Floods; Remote Sensing; Sentinel-1 SAR; Segmentation; Change Detection; DEM; Data Fusion; Time Series; Deep Learning; Unsupervised Learning; Contrastive Learning; Self-Attention; Convolutional LSTM; Variational AutoEncoder VAE ; Geoinformatik; Geoinformatics;

   Sammanfattning : Human civilization has an increasingly powerful influence on the earthsystem. Affected by climate change and land-use change, floods are occurringacross the globe and are expected to increase in the coming years. Currentsituations urge more focus on efficient monitoring of floods and detecting impactedareas. LÄS MER

7. 5. Mold2012 : a new gravimetric quasigeoid model over Moldova

   Författare :Uliana Danila; Lars E. Sjöberg; Stig-Göran Mårtensson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geoid; quasigeoid; KTH method; corrective surface;

   Sammanfattning : In order to be able to use the operational Moldavian GNSS Positioning System MOLDPOS efficiently for the determination of normal heights in surveying engineering, e.g. during the construction of a road, an accurate quasigeoid model is needed. LÄS MER