GNSS-нівелювання

A number of factors can significantly affect the accuracy of height determination when applying the GNSS leveling method. In general, it is possible to distinguish those related to the process of GNSS observations and their post-processing, and those related to the selection of the geoid/quasi-geoid height model. This work focuses on aspects of GNSS leveling accuracy when choosing global geoid models. In particular, to better ensure accuracy, it is important to understand the significance of the heights tidal system selection of global geoid models.

Widespread use of GPS / GNSS technology sets the task of determining the normal (orthometric) heights of points. We know that it is necessary to determine the initial level surface – the surface of the geoid / quasigeoid. Determination of the quasigeoid surface can be performed by: 1) a gravimetric readout in the relevant region and building the regional geoid / quasigeoid; 2) a model of potential of gravitational field of the Earth; 3) an interpolation of quasigeoid’s heights on a surface given by leveling reference points, on which GNSS-leveling is carried.