The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network
This paper investigates the normal-orthometric correction used in the definition of the Australian Height Datum, and also computes and evaluates normal and Helmert orthometric corrections for the Australian National Levelling Network (ANLN). Testing these corrections in Australia is important to est...
| Main Authors: | , , |
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| Format: | Journal Article |
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Springer - Verlag
2010
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| Online Access: | http://hdl.handle.net/20.500.11937/4685 |
| _version_ | 1848744585867558912 |
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| author | Filmer, Michael Featherstone, Will Kuhn, Michael |
| author_facet | Filmer, Michael Featherstone, Will Kuhn, Michael |
| author_sort | Filmer, Michael |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | This paper investigates the normal-orthometric correction used in the definition of the Australian Height Datum, and also computes and evaluates normal and Helmert orthometric corrections for the Australian National Levelling Network (ANLN). Testing these corrections in Australia is important to establish which height system is most appropriate for any new Australian vertical datum. An approximate approach to assigning gravity values to ANLN benchmarks (BMs) is used, where the EGM2008-modelled gravity field is used to "re-construct" observed gravity at the BMs. Network loop closures (for first- and second-order levelling) indicate reduced misclosures for all height corrections considered, particularly in the mountainous regions of south eastern Australia. Differences between Helmert orthometric and normal-orthometric heights reach 44 cm in the Australian Alps, and differences between Helmert orthometric and normal heights are about 26 cm in the same region. Normal orthometric heights differ from normal heights by up to 18 cm in mountainous regions >2,000 m. This indicates that the quasigeoid is not compatible with normal-orthometric heights in Australia. |
| first_indexed | 2025-11-14T06:03:49Z |
| format | Journal Article |
| id | curtin-20.500.11937-4685 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:03:49Z |
| publishDate | 2010 |
| publisher | Springer - Verlag |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-46852017-09-13T15:54:29Z The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network Filmer, Michael Featherstone, Will Kuhn, Michael AHD Vertical datums EGM2008 Height systems This paper investigates the normal-orthometric correction used in the definition of the Australian Height Datum, and also computes and evaluates normal and Helmert orthometric corrections for the Australian National Levelling Network (ANLN). Testing these corrections in Australia is important to establish which height system is most appropriate for any new Australian vertical datum. An approximate approach to assigning gravity values to ANLN benchmarks (BMs) is used, where the EGM2008-modelled gravity field is used to "re-construct" observed gravity at the BMs. Network loop closures (for first- and second-order levelling) indicate reduced misclosures for all height corrections considered, particularly in the mountainous regions of south eastern Australia. Differences between Helmert orthometric and normal-orthometric heights reach 44 cm in the Australian Alps, and differences between Helmert orthometric and normal heights are about 26 cm in the same region. Normal orthometric heights differ from normal heights by up to 18 cm in mountainous regions >2,000 m. This indicates that the quasigeoid is not compatible with normal-orthometric heights in Australia. 2010 Journal Article http://hdl.handle.net/20.500.11937/4685 10.1007/s00190-010-0388-0 Springer - Verlag fulltext |
| spellingShingle | AHD Vertical datums EGM2008 Height systems Filmer, Michael Featherstone, Will Kuhn, Michael The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network |
| title | The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network |
| title_full | The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network |
| title_fullStr | The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network |
| title_full_unstemmed | The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network |
| title_short | The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network |
| title_sort | effect of egm2008-based normal, normal-orthometric and helmert orthometric height systems on the australian levelling network |
| topic | AHD Vertical datums EGM2008 Height systems |
| url | http://hdl.handle.net/20.500.11937/4685 |