منابع مشابه
A Gravimetric Geoid Model as a Vertical Datum in Canada
The need for a new vertical datum in Canada dates back to 1976 when a study group at the Geodetic Survey Division (GSD) of Natural Resources Canada investigated problems related to the existing vertical reference system (CGVD28) and recommended a redefinition of the vertical datum. The US National Geodetic Survey and GSD cooperated in the development of a new North American Vertical Datum (NAVD...
متن کاملGravimetric Geoid Determination by Using Terrestrial and Satellite-derived Data
Being a fundamental vertical reference surface, the use of the geoid is not limited to geodesy/geodetic applications. It is also used, but not limited to, in geophysics (i.e. interpretation of the Earth’s internal structure, solid earth science), geology (i.e. subsurface delineation), oceanography, and mapping/geographic information systems (GIS)/national spatial development infrastructure (NSD...
متن کاملProgress Towards a Gravimetric Geoid for New Zealand and a Single National Vertical Datum
New Zealand, unlike most countries, does not have a single national vertical datum. Instead, twelve separate and poorly linked primary levelling networks tied to twelve different tide gauges are used. The current vertical datums are based on the false assumption that mean sea level, measured at the twelve tide gauges, corresponds to the same equipotential surface. Due to the effects of long-per...
متن کاملThe combination of GNSS-levelling data and gravimetric (quasi-) geoid heights in the presence of noise
We propose a methodology for the combination of a gravimetric (quasi-) geoid with GNSS-levelling data in the presence of noise with correlations and/or spatially varying noise variances. It comprises two steps: first, a gravimetric (quasi-) geoid is computed using the available gravity data, which, in a second step, is improved using ellipsoidal heights at benchmarks provided by GNSS once they ...
متن کاملMean kernels to improve gravimetric geoid determination based on modified Stokes's integration
Gravimetric geoid computation is often based on modified Stokes’s integration, where Stokes’s integral is evaluated with some stochastic or deterministic kernel modification. Accurate numerical evaluation of Stokes’s integral requires the modified kernel to be integrated across the area of each discretised grid cell (mean kernel). Evaluating the modified kernel at the centre of the cell (point ...
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ژورنال
عنوان ژورنال: Geophysical Journal International
سال: 1974
ISSN: 0956-540X,1365-246X
DOI: 10.1111/j.1365-246x.1974.tb01238.x