AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights
In an absolute sense, AUSGeoid09 is an order of magnitude more accurate than AUSGeoid98 at converting ellipsoidal heights to Australian Height Datum (AHD) heights and vice versa. Results of this study show AUSGeoid09 can be used to compute AHD heights from Global Navigation Satellite System (GNSS) e...
| Main Authors: | , , , |
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| Format: | Journal Article |
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Taylor & Francis Asia Pacific (Singapore)
2011
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| Online Access: | http://hdl.handle.net/20.500.11937/32454 |
| _version_ | 1848753668315152384 |
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| author | Brown, N. Featherstone, Will Hu, G. Johnston, G. |
| author_facet | Brown, N. Featherstone, Will Hu, G. Johnston, G. |
| author_sort | Brown, N. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | In an absolute sense, AUSGeoid09 is an order of magnitude more accurate than AUSGeoid98 at converting ellipsoidal heights to Australian Height Datum (AHD) heights and vice versa. Results of this study show AUSGeoid09 can be used to compute AHD heights from Global Navigation Satellite System (GNSS) ellipsoidal heights with an uncertainty of less than +/-0.03 m (one sigma). The improvement is largely due to the inclusion of a geometric component in AUSGeoid09 that accountsfor the spatially varying offset between a gravimetric quasigeoid model and the AHD. This geometric component was calculated using least squares collocation in cross validation mode and then added to the gravimetric quasigeoid. Although previous AUSGeoid models were used to convert GNSS ellipsoidal heights to the AHD and vice versa, none until now have accounted for the gravimetric quasigeoid to AHD offsets. This offset is a consequence of how the AHD was realised and has commonly resultedin misfits of ~0.5 m or more. When used with GNSS technology, AUSGeoid09 can replace the need for traditional third-order levelling (Class LC; 12 roo k) in many situations. Relative tests of AUSGeoid09 over a continent-wide set of over 20 million baselines showed that it can deliver better than Class LC tolerances in 99 percent of cases. The model accepts a user?s GDA94 latitude, longitude and ellipsoidal height and returns an AHD height and deviations of the vertical. AUSGeoid09 is now availablefree-of-charge on the Geoscience Australia website (<a href="http://www.ga.gov.au/geodesy/ausgeoid/nvalcomp.jsp">http://www.ga.gov.au/geodesy/ausgeoid/nvalcomp.jsp</a>). |
| first_indexed | 2025-11-14T08:28:10Z |
| format | Journal Article |
| id | curtin-20.500.11937-32454 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:28:10Z |
| publishDate | 2011 |
| publisher | Taylor & Francis Asia Pacific (Singapore) |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-324542017-09-13T15:56:36Z AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights Brown, N. Featherstone, Will Hu, G. Johnston, G. AUSGeoid AHD quasigeoid GNSS heighting In an absolute sense, AUSGeoid09 is an order of magnitude more accurate than AUSGeoid98 at converting ellipsoidal heights to Australian Height Datum (AHD) heights and vice versa. Results of this study show AUSGeoid09 can be used to compute AHD heights from Global Navigation Satellite System (GNSS) ellipsoidal heights with an uncertainty of less than +/-0.03 m (one sigma). The improvement is largely due to the inclusion of a geometric component in AUSGeoid09 that accountsfor the spatially varying offset between a gravimetric quasigeoid model and the AHD. This geometric component was calculated using least squares collocation in cross validation mode and then added to the gravimetric quasigeoid. Although previous AUSGeoid models were used to convert GNSS ellipsoidal heights to the AHD and vice versa, none until now have accounted for the gravimetric quasigeoid to AHD offsets. This offset is a consequence of how the AHD was realised and has commonly resultedin misfits of ~0.5 m or more. When used with GNSS technology, AUSGeoid09 can replace the need for traditional third-order levelling (Class LC; 12 roo k) in many situations. Relative tests of AUSGeoid09 over a continent-wide set of over 20 million baselines showed that it can deliver better than Class LC tolerances in 99 percent of cases. The model accepts a user?s GDA94 latitude, longitude and ellipsoidal height and returns an AHD height and deviations of the vertical. AUSGeoid09 is now availablefree-of-charge on the Geoscience Australia website (<a href="http://www.ga.gov.au/geodesy/ausgeoid/nvalcomp.jsp">http://www.ga.gov.au/geodesy/ausgeoid/nvalcomp.jsp</a>). 2011 Journal Article http://hdl.handle.net/20.500.11937/32454 10.1080/14498596.2011.580498 Taylor & Francis Asia Pacific (Singapore) fulltext |
| spellingShingle | AUSGeoid AHD quasigeoid GNSS heighting Brown, N. Featherstone, Will Hu, G. Johnston, G. AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights |
| title | AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights |
| title_full | AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights |
| title_fullStr | AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights |
| title_full_unstemmed | AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights |
| title_short | AUSGeoid09: a more direct and more accurate model for converting ellipsoidal heights to AHD heights |
| title_sort | ausgeoid09: a more direct and more accurate model for converting ellipsoidal heights to ahd heights |
| topic | AUSGeoid AHD quasigeoid GNSS heighting |
| url | http://hdl.handle.net/20.500.11937/32454 |