0000000000464895
AUTHOR
Ansis Zarins
Evaluation of quasi-geoid model based on astrogeodetic measurements: case of Latvia
Abstract Since the development of GNSS techniques, the determination of a precise quasi-geoid model has become even more actual. In terms of this project the staff of the Institute of Geodesy and Geoinformatics (GGI) has developed a new quasi-geoid model based on DFHRS (Digital Finite-element Height Reference Surface) approach additionally using astrogeodetic measurements – vertical deflections (VD), which can be observed by a Digital zenith camera. This paper evaluates a quasi-geoid model results based on vertical deflections, as a study area using the territory of Latvia: the standard deviation of the solution is equal to 0.006 m with observation residuals after the adjustment of minimum …
Digital Zenith Cameras Results and Its Use in DFHRS v.4.3 Software for Quasi-Geoid Determination
The design of digital zenith camera was started in 2010 by Institute of Geodesy and Geoinformatics. Since then the prototype of digital zenith camera has been developed. Now, after improvements of design and manufacturing of the second version, it has reached operational status. This paper describes the construction of zenith camera and features of its control software. The results of vertical deflections' measurements are discussed. At the moment measurements are done in Riga region and are used in DFHRS v.4.3 software in order to check and improve local quasigeoid model. It is a new method of quasigeoid model determination and has not been used in Latvia before. DFHRS (Digital Finite Elem…