Optimum Resolution and Size of DTM during Modelling Topographic Effect

Modelling the effects of topographic masses which bear local changes of the gravity field is exceptionally important in the contemporary scientific and practical implementations. The topography effect in this paper is analysed by the digital terrain model of the Republic of Serbia, developed on the basis of the topographic map at the scale of 1:25 000 and by the hypothesis on the equal density of surface layers of the Earth crust. The shortwave characteristic as an impact of the local topography was analysed in parts with different topography for the region of Belgrade and Pal-clan. The gravity field parameters were determined in points of the reference GPS network of the Republic of Serbia and points of the Paracin basis, with the purpose of comparing gravimetric vertical deflections with astro-geodetic vertical deflections