Investigations of geoid models in Finland - Towards GNSS-related height system
In Fennoscandia, heights and their relations between each other are in constant change due to the post-glacial rebound, so the national height system needs to be updated occasionally. Traditionally, the update has been done with a method known as precise levelling, which is accurate but considered s...
Published in: | Geodesy and Cartography |
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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Aalto University
2022
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Online Access: | https://aaltodoc.aalto.fi/handle/123456789/117900 |
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Aalto University Publication Archive (Aaltodoc) |
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Geoinformatics geoid (quasi-)geoid model GNSS national height system GOCE GRACE gravity post-glacial rebound Finland Geoidi (kvasi)geoidimalli valtakunnallinen korkeusjärjestelmä painovoima jääkauden jälkeinen maankohoaminen Suomi |
spellingShingle |
Geoinformatics geoid (quasi-)geoid model GNSS national height system GOCE GRACE gravity post-glacial rebound Finland Geoidi (kvasi)geoidimalli valtakunnallinen korkeusjärjestelmä painovoima jääkauden jälkeinen maankohoaminen Suomi Saari, Timo Investigations of geoid models in Finland - Towards GNSS-related height system |
topic_facet |
Geoinformatics geoid (quasi-)geoid model GNSS national height system GOCE GRACE gravity post-glacial rebound Finland Geoidi (kvasi)geoidimalli valtakunnallinen korkeusjärjestelmä painovoima jääkauden jälkeinen maankohoaminen Suomi |
description |
In Fennoscandia, heights and their relations between each other are in constant change due to the post-glacial rebound, so the national height system needs to be updated occasionally. Traditionally, the update has been done with a method known as precise levelling, which is accurate but considered slow, laborious, and expensive. This dissertation studied the modern, mainly Global Navigation Satellite System (GNSS) -based, height determination techniques that could replace precise levelling as the method for the next national height system of Finland. GNSS-based techniques provide the height component relative to a reference ellipsoid, which is a mathematical surface and therefore lacks a physical connection to the Earth – i.e. have no information on the direction of water flow. Here, we need a (quasi-)geoid model to tie the ellipsoidal heights to the surface of the Earth and to national height systems. The (quasi-)geoid model's accuracy is therefore crucial with GNSS/geoid techniques. The presented case study gave us knowledge from several techniques. The static GNSS proved the most promising, as the result was close to the one from precise levelling. However, due to the closeness of the evaluation points, the relative error of the geoid between them is negligible in practice, which is not the case in a nationwide network. The national quasi-geoid model of Finland, FIN2005N00, was created nearly two decades ago. The gravity satellites, Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) and Gravity Recovery and Climate Experiment (GRACE), have since measured the Earth's gravitational field in unprecedented detail. At the time, we investigated all the published GOCE and GRACE global gravitational models (GGM) in Finland. We learned that the best models already performed at the same level or better than the pre-GOCE era high-resolution models. The most suitable model, DIR5, was chosen as a background model with the high-resolution EIGEN-6C4 in the quasi-geoid modelling of Finland. The new and present ... |
author2 |
Bilker-Koivula, Mirjam, Dr., Finnish Geospatial Research Institute, Finland Poutanen, Markku, Prof., Finnish Geospatial Research Institute, Finland Insinööritieteiden korkeakoulu School of Engineering Rakennetun ympäristön laitos Department of Built Environment Nordman, Maaria, Prof., Aalto University, Department of Built Environment, Finland Aalto-yliopisto Aalto University |
format |
Doctoral or Postdoctoral Thesis |
author |
Saari, Timo |
author_facet |
Saari, Timo |
author_sort |
Saari, Timo |
title |
Investigations of geoid models in Finland - Towards GNSS-related height system |
title_short |
Investigations of geoid models in Finland - Towards GNSS-related height system |
title_full |
Investigations of geoid models in Finland - Towards GNSS-related height system |
title_fullStr |
Investigations of geoid models in Finland - Towards GNSS-related height system |
title_full_unstemmed |
Investigations of geoid models in Finland - Towards GNSS-related height system |
title_sort |
investigations of geoid models in finland - towards gnss-related height system |
publisher |
Aalto University |
publishDate |
2022 |
url |
https://aaltodoc.aalto.fi/handle/123456789/117900 |
genre |
Fennoscandia |
genre_facet |
Fennoscandia |
op_relation |
Aalto University publication series DOCTORAL THESES 171/2022 [Publication 1]: Saari, T., Poutanen, M., Saaranen, V., Kaartinen, H., Kukko, A., Nyberg, S. (2015). Height Determination Techniques for the Next National Height System of Finland - A Case Study. Geodesy and Cartography. 41(4):145–155. DOI:10.3846/20296991.2015.1120387 [Publication 2]: Saari, T., Bilker-Koivula, M. (2015). Evaluation of GOCE-based Global Geoid Models in Finnish Territory. Newton's Bulletin. 5:25–36. https://www.isgeoid.polimi.it/Newton/Newton_5/04_Saari_25_36.pdf [Publication 3]: Saari, T., Bilker-Koivula, M. (2017). Applying the GOCE-based GGMs for the quasi-geoid modelling of Finland. Journal of Applied Geodesy. 12(1):15–27. DOI:10.1515/jag-2017-0020 [Publication 4]: Saari, T., Bilker-Koivula, M., Koivula, H., Nordman, M., Häkli, P., Lahtinen, S. (2021). Validating Geoid Models with Marine GNSS Measurements, Sea Surface Models, and Additional Gravity Observations in the Gulf of Finland. Marine Geodesy. 44(3):196–214. Full text in Acris/Aaltodoc: http://urn.fi/URN:NBN:fi:aalto-202106027192. DOI:10.1080/01490419.2021.1889727 978-952-64-1029-6 (electronic) 978-952-64-1028-9 (printed) 1799-4942 (electronic) 1799-4934 (printed) 1799-4934 (ISSN-L) https://aaltodoc.aalto.fi/handle/123456789/117900 URN:ISBN:978-952-64-1029-6 |
op_doi |
https://doi.org/10.3846/20296991.2015.1120387 https://doi.org/10.1515/jag-2017-0020 https://doi.org/10.1080/01490419.2021.1889727 |
container_title |
Geodesy and Cartography |
container_volume |
41 |
container_issue |
4 |
container_start_page |
145 |
op_container_end_page |
155 |
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1765997554779029504 |
spelling |
ftaaltouniv:oai:aaltodoc.aalto.fi:123456789/117900 2023-05-15T16:12:17+02:00 Investigations of geoid models in Finland - Towards GNSS-related height system Geoidimallien tutkimukset Suomessa – Kohti GNSS-pohjaista korkeusjärjestelmää Saari, Timo Bilker-Koivula, Mirjam, Dr., Finnish Geospatial Research Institute, Finland Poutanen, Markku, Prof., Finnish Geospatial Research Institute, Finland Insinööritieteiden korkeakoulu School of Engineering Rakennetun ympäristön laitos Department of Built Environment Nordman, Maaria, Prof., Aalto University, Department of Built Environment, Finland Aalto-yliopisto Aalto University 2022 application/pdf https://aaltodoc.aalto.fi/handle/123456789/117900 en eng Aalto University Aalto-yliopisto Aalto University publication series DOCTORAL THESES 171/2022 [Publication 1]: Saari, T., Poutanen, M., Saaranen, V., Kaartinen, H., Kukko, A., Nyberg, S. (2015). Height Determination Techniques for the Next National Height System of Finland - A Case Study. Geodesy and Cartography. 41(4):145–155. DOI:10.3846/20296991.2015.1120387 [Publication 2]: Saari, T., Bilker-Koivula, M. (2015). Evaluation of GOCE-based Global Geoid Models in Finnish Territory. Newton's Bulletin. 5:25–36. https://www.isgeoid.polimi.it/Newton/Newton_5/04_Saari_25_36.pdf [Publication 3]: Saari, T., Bilker-Koivula, M. (2017). Applying the GOCE-based GGMs for the quasi-geoid modelling of Finland. Journal of Applied Geodesy. 12(1):15–27. DOI:10.1515/jag-2017-0020 [Publication 4]: Saari, T., Bilker-Koivula, M., Koivula, H., Nordman, M., Häkli, P., Lahtinen, S. (2021). Validating Geoid Models with Marine GNSS Measurements, Sea Surface Models, and Additional Gravity Observations in the Gulf of Finland. Marine Geodesy. 44(3):196–214. Full text in Acris/Aaltodoc: http://urn.fi/URN:NBN:fi:aalto-202106027192. DOI:10.1080/01490419.2021.1889727 978-952-64-1029-6 (electronic) 978-952-64-1028-9 (printed) 1799-4942 (electronic) 1799-4934 (printed) 1799-4934 (ISSN-L) https://aaltodoc.aalto.fi/handle/123456789/117900 URN:ISBN:978-952-64-1029-6 Geoinformatics geoid (quasi-)geoid model GNSS national height system GOCE GRACE gravity post-glacial rebound Finland Geoidi (kvasi)geoidimalli valtakunnallinen korkeusjärjestelmä painovoima jääkauden jälkeinen maankohoaminen Suomi G5 Artikkeliväitöskirja text Doctoral dissertation (article-based) Väitöskirja (artikkeli) 2022 ftaaltouniv https://doi.org/10.3846/20296991.2015.1120387 https://doi.org/10.1515/jag-2017-0020 https://doi.org/10.1080/01490419.2021.1889727 2022-12-21T23:57:24Z In Fennoscandia, heights and their relations between each other are in constant change due to the post-glacial rebound, so the national height system needs to be updated occasionally. Traditionally, the update has been done with a method known as precise levelling, which is accurate but considered slow, laborious, and expensive. This dissertation studied the modern, mainly Global Navigation Satellite System (GNSS) -based, height determination techniques that could replace precise levelling as the method for the next national height system of Finland. GNSS-based techniques provide the height component relative to a reference ellipsoid, which is a mathematical surface and therefore lacks a physical connection to the Earth – i.e. have no information on the direction of water flow. Here, we need a (quasi-)geoid model to tie the ellipsoidal heights to the surface of the Earth and to national height systems. The (quasi-)geoid model's accuracy is therefore crucial with GNSS/geoid techniques. The presented case study gave us knowledge from several techniques. The static GNSS proved the most promising, as the result was close to the one from precise levelling. However, due to the closeness of the evaluation points, the relative error of the geoid between them is negligible in practice, which is not the case in a nationwide network. The national quasi-geoid model of Finland, FIN2005N00, was created nearly two decades ago. The gravity satellites, Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) and Gravity Recovery and Climate Experiment (GRACE), have since measured the Earth's gravitational field in unprecedented detail. At the time, we investigated all the published GOCE and GRACE global gravitational models (GGM) in Finland. We learned that the best models already performed at the same level or better than the pre-GOCE era high-resolution models. The most suitable model, DIR5, was chosen as a background model with the high-resolution EIGEN-6C4 in the quasi-geoid modelling of Finland. The new and present ... Doctoral or Postdoctoral Thesis Fennoscandia Aalto University Publication Archive (Aaltodoc) Geodesy and Cartography 41 4 145 155 |