Computation of precise geoid model of Auvergne using current UNB Stokes- Helmert’s approach

Juraj JANÁK; Petr VANÍČEK; Ismael FOROUGHI; Robert KINGDON; Michael B. SHENG; Marcelo C. SANTOS

doi:10.1515/congeo-2017-0011

Juraj JANÁK Department of Theoretical Geodesy, Slovak University of Technology
Petr VANÍČEK Department of Geodesy and Geomatics, University of New Brunswick
Ismael FOROUGHI Department of Geodesy and Geomatics, University of New Brunswick
Robert KINGDON Department of Geodesy and Geomatics, University of New Brunswick
Michael B. SHENG Department of Geodesy and Geomatics, University of New Brunswick
Marcelo C. SANTOS Department of Geodesy and Geomatics, University of New Brunswick

DOI: https://doi.org/10.1515/congeo-2017-0011

Keywords: gravity field, geoid, Stokes-Helmert’s method, downward continuation, topographical density variation, rigorous orthometric heights

Abstract

The aim of this paper is to show a present state-of-the-art precise gravimetric geoid determination using the UNB Stokes-Helmert’s technique in a simple schematic way. A detailed description of a practical application of this technique in the Auvergne test area is also provided. In this paper, we discuss the most problematic parts of the solution: correct application of topographic and atmospheric effects including the lateral topographical density variations, downward continuation of gravity anomalies from the Earth surface to the geoid, and the optimal incorporation of the global gravity field into the final geoid model. The final model is tested on 75 GNSS/levelling points supplied with normal Molodenskij heights, which for this investigation are transformed to rigorous orthometric heights. The standard deviation of the computed geoid model is 3.3 cm without applying any artificial improvement which is the same as that of the most accurate quasigeoid.