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| Titel |
Contribution of the GRACE and GOCE models to a geopotential-based geodetic vertical datum in Canada |
| VerfasserIn |
Jianliang Huang, Marc Véronneau |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250081228
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| Zusammenfassung |
| Natural Resources Canada (NRCan) is presently getting ready to release a new vertical datum
for the country by November 2013. The Canadian Geodetic Vertical Datum of 2013
(CGVD2013) will be defined by the geopotential surface 62,636,856.0 m2s-2, which was
agreed between the USA and Canada. This geopotential value is representative of the mean
coastal sea level around North America and is consistent with IERS Conventions 2010.
CGVD2013 is to replace the current levelling-based Canadian Geodetic Vertical Datum of
1928 (CGVD28). A GRACE and GOCE geopotential model will be spectrally combined with
the North American terrestrial gravity data and a global Digital Elevation Model to determine
the high-resolution Canadian Gravimetric Geoid model 2013 (CGG2013). CGG2013 will
be the first geoid model realizing officially CGVD2013. NRCan will apply the
remove-compute-restore Helmert-Stokes scheme for its development. As part of
this significant undertaking, this study focuses on assessing the contribution of
the latest GRACE and GOCE models in terms of spectral content to enhance our
understanding of the gravity field over Canada, ultimately improving the realization of
CGVD2013. These GRACE and GOCE-based models include EGM08, EIGEN-6C,
EIGEN-6C2, DIR_R3, TIM_R3, GOCO03S and other possible newer releases.
The geoid models are determined by combining the satellite-only models with the
terrestrial gravity data by the spectrally modified Stokes formula. The resulting
geoid models will be compared with independent GPS-Levelling, gravity and other
data for Canada and sub-regions. The results of this study will allow NRCan to
select the ‘best’ GRACE and GOCE model for the development of CGG2013 and to
determine its optimal spectral combination with terrestrial gravity data in Canada. |
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