Gravimetric geoid model determination of Central Ukraine area using combination of LSC and truncated SHA methods

Abstract

In this paper we investigate the possibility of combining least squares collocation (LSC) and spherical functions (spherical harmonic analysis SHA) with real eigenvalues methods for calculating the geoid model. A comparison of local analytical covariance functions calculated on the basis of Legendre polynomials and polynomials with real eigenvalues is carried out. We computed geoid model for the region of Central Ukraine using the proposed method and assessed its accuracy. The input data for the computation of model are gravity anomalies, obtained after filtering the results of digitization of gravimetric maps by the 3σ criterion, functionals of the Earth's gravity field from the global gravity model EGM2008 and GNSS leveling data. The standard deviation was found between the model values of the geoid height and the values, obtained from GNSS leveling at the points of the state geodetic network. The accuracy of the geoid model obtained using the proposed method is approximately 2 cm. Such accuracy is primarily conditioned by the quality of initial data. To increase the accuracy of the model it is necessary to carry out a complex of gravimetric works in the studied region.