Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data
At the beginning of the twenty-first century, a technological change took place in geodetic astronomy by the development of Digital Zenith Camera Systems (DZCS). Such instruments provide vertical deflection data at an angular accuracy level of 0".1 and better. Recently, DZCS have been employed...
| Main Authors: | , |
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| Format: | Journal Article |
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Springer - Verlag
2009
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| Online Access: | http://hdl.handle.net/20.500.11937/6497 |
| _version_ | 1848745092180869120 |
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| author | Hirt, Christian Flury, J. |
| author_facet | Hirt, Christian Flury, J. |
| author_sort | Hirt, Christian |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | At the beginning of the twenty-first century, a technological change took place in geodetic astronomy by the development of Digital Zenith Camera Systems (DZCS). Such instruments provide vertical deflection data at an angular accuracy level of 0".1 and better. Recently, DZCS have been employed for the collection of dense sets of astrogeodetic vertical deflection data in several test areas in Germany with high-resolution digital terrain model (DTM) data (10-50 m resolution) available. These considerable advancements motivate a new analysis of the method of astronomical-topographic levelling, which uses DTM data for the interpolation between the astrogeodetic stations. We present and analyse a least-squares collocation technique that uses DTM data for the accurate interpolation of vertical deflection data. The combination of both data sets allows a precise determination of the gravity field along profiles, even in regions with a rugged topography. The accuracy of the method is studied with particular attention on the density of astrogeodetic stations. The error propagation rule of astronomical levelling is empirically derived. It accounts for the signal omission that increases with the station spacing. In a test area located in the German Alps, the method was successfully applied to the determination of a quasigeoid profile of 23 km length. For a station spacing from a few 100 m to about 2 km, the accuracy of the quasigeoid was found to be about 1-2 mm, which corresponds to a relative accuracy of about 0.05-0.1 ppm. Application examples are given, such as the local and regional validation of gravity field models computed from gravimetric data and the economic gravity field determination in geodetically less covered regions. |
| first_indexed | 2025-11-14T06:11:51Z |
| format | Journal Article |
| id | curtin-20.500.11937-6497 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:11:51Z |
| publishDate | 2009 |
| publisher | Springer - Verlag |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-64972017-09-13T15:53:53Z Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data Hirt, Christian Flury, J. Digital Terrain Model (DTM) Digital Zenith Camera System (DZCS) vertical deflection least-squares collocation (LSC) astronomical levelling At the beginning of the twenty-first century, a technological change took place in geodetic astronomy by the development of Digital Zenith Camera Systems (DZCS). Such instruments provide vertical deflection data at an angular accuracy level of 0".1 and better. Recently, DZCS have been employed for the collection of dense sets of astrogeodetic vertical deflection data in several test areas in Germany with high-resolution digital terrain model (DTM) data (10-50 m resolution) available. These considerable advancements motivate a new analysis of the method of astronomical-topographic levelling, which uses DTM data for the interpolation between the astrogeodetic stations. We present and analyse a least-squares collocation technique that uses DTM data for the accurate interpolation of vertical deflection data. The combination of both data sets allows a precise determination of the gravity field along profiles, even in regions with a rugged topography. The accuracy of the method is studied with particular attention on the density of astrogeodetic stations. The error propagation rule of astronomical levelling is empirically derived. It accounts for the signal omission that increases with the station spacing. In a test area located in the German Alps, the method was successfully applied to the determination of a quasigeoid profile of 23 km length. For a station spacing from a few 100 m to about 2 km, the accuracy of the quasigeoid was found to be about 1-2 mm, which corresponds to a relative accuracy of about 0.05-0.1 ppm. Application examples are given, such as the local and regional validation of gravity field models computed from gravimetric data and the economic gravity field determination in geodetically less covered regions. 2009 Journal Article http://hdl.handle.net/20.500.11937/6497 10.1007/s00190-007-0173-x Springer - Verlag fulltext |
| spellingShingle | Digital Terrain Model (DTM) Digital Zenith Camera System (DZCS) vertical deflection least-squares collocation (LSC) astronomical levelling Hirt, Christian Flury, J. Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| title | Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| title_full | Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| title_fullStr | Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| title_full_unstemmed | Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| title_short | Astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| title_sort | astronomical-topographic levelling using high-precision astrogeodetic vertical deflections and digital terrain model data |
| topic | Digital Terrain Model (DTM) Digital Zenith Camera System (DZCS) vertical deflection least-squares collocation (LSC) astronomical levelling |
| url | http://hdl.handle.net/20.500.11937/6497 |