View Item 

Evidence of a north-south trend between AUSGeoid98 and AHD in southwest Australia

Access Status
Open access
Authors
Featherstone, Will
Date
2004
Type
Journal Article

Metadata
Show full item record
Citation
Featherstone, W.E.. 2004. Evidence of a north-south trend between AUSGeoid98 and AHD in southwest Australia. Survey Review 37 (291): 334-343.
Source Title
Survey Review
Additional URLs
Faculty
Division of Resources and Environment
Department of Spatial Sciences
Remarks

Article first published in Survey Review 2004 37(291)pp. 334-343. Survey Review ISSN 0039-6265 is published by Commonwealth Association for Surveying and Land Economy (CASLE) in the UK.

A link to the Survey Review website can be found at http://www.surveyreview.org

URI
Collection
Abstract

The AUSGeoid98 gravimetric model has been compared with 48 GPD-levelling points at a ~50km spacing across part of the southwest of Western Australia. This is arguably the best subset of GPS-derived ellipsoidal heights in Australia with na internally estimated precision of < +-9mm. The spirit-levelled heights were tied to the Australian Height Datum(AHD)using class C techniques [12mm-root-km allowable misclose]. The comparisons shoe that AUSGeoid98 gives a GPS height transformation to the AHD with a precision of ~+-13cm, which is less than reported earlier (~+-36 cm)for a nationwide dataset. A clear north-south trend of ~0.81 mm/km [ppm] is also evident in the differences; of which approximately one-third is attributable to a north-south error in the AHD induced by dominant north-south sea surface topography effects at the nearby fixed tide gauges. After removal of this north-south trend, the standard deviation of the differences reduces to ~5 cm.