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| Titel |
Average Offsets of the Local Vertical Datums in New Zealand Relative to the World Height System |
| VerfasserIn |
Robert Tenzer, Ahmed Abdalla, Viliam Vatrt, Nadim Dayoub |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034343
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| Zusammenfassung |
| Abstract: We determine the average offsets of 12 major local vertical datums (LVDs) in New
Zealand relative to the World Height System (WHS). The LVD offsets are estimated using
the EGM2008 global geopotential model coefficients complete to degree 2160
of spherical harmonics and the GPS-levelling data. The WHS is defined by the
currently adopted best-estimated geoidal geopotential value W0= 62636856 m2s-2.
Our test results reveal that the average offsets of 12 major local vertical datums
situated throughout the South and North Islands of New Zealand range from -0.25 to
1.34 m. The EGM2008 and GPS-levelling data are further used to compute the
differences between the NZGeoid05 regional quasigeoid model and the EGM2008 global
quasigeoid model. The same analysis is done for the NZGeoid09 which is the latest
version of the official national quasigeoid model for New Zealand. The numerical
results at the network of GPS-levelling points show that the differences between the
NZGeoid05 and the EGM2008 quasigeoid models vary from 0.24 to 0.81 m with the
mean of 0.56 m. The corresponding differences between the NZGeoid09 and the
EGM2008 quasigeoid models vary from 0.27 to 1.14 m with the mean of 0.51
m.
Keywords: geoidal geopotential value, GPS-leveling data, local vertical datum, World
Height System |
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