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Regional Models

New Zealand (NZGM2010)

  Authors: A. Abdalla, R. Tenzer     Created: 2010    Resp: A. Abdalla  
      Status: PUBLIC    
The NZGM2010 quasi-geoid model for New Zealand and its continental shelf has been computed by applying the method developed at the KTH, which is based on least-squares modification of Stokes formula. Two sets of regional gravity data have been used: the altimetry-derived gravity anomalies from the DNSC08 marine gravity database (offshore) and the ground gravity measurements from the GNS Science gravity database (onshore). The long-wavelength contribution has been taken from the EIGEN-GRACE02S global geopotential model up to degree and order 65. The topographic effect has been computed from the 1x1 arc-sec detailed digital terrain model of New Zealand and from the 30x30 arc-sec global elevation data of SRTM30_PLUS V5.0. The NZGM2010 model is computed on a 2x2 arc-min geographical grid over the computation area bounded by the parallels of 28 and 57 arc-deg southern latitude, and the meridians of 163 and 187 arc-deg of eastern longitude. A least-squares adjustment with a 7-parameter model has been applied to combine the gravimetric model with GPS-levelling data, consisting of 2320 points from the LINZ geodetic database. The resulting model is therefore in the NZGD2000 datum, which is align to ITRF1996 at the reference epoch of January 1st, 2000. After the GPS-levelling fitting, the resulting accuracy in New Zealand is 7 cm in terms of the standard deviation of differences between the NZ-KTH10 quasi-geoid model and the used GPS-levelling data. NZGM2010 is an experimental model based on the recent studies, while the official one for New Zealand is NZGEOID2009.

A. Abdalla, R. Tenzer (2011). The evaluation of the New Zealand's geoid model using the KTH method. Journal of Geodesy and Cartography, 37(1), pp. 5-14.
A. Abdalla (2013). The combined modelling of the rgional quasigeoid of New Zealand using gravity and GPS/levelling data, PhD thesis, University of Otago, New Zealand.

New Zealand