On the improvement of the orthometric heights via GNSS-levelling: The case of Drama area in Greece

摘要

In the present study we deal with the problem of the improvement of the orthometric heights, using a parametric model of four parameters. This application is widely used in practice from many researchers and agencies. We implement the aforementioned fitting model in the area of Drama in Greece. We estimated the correction surface and we compare our results with the officially released model for the orthometric heights. The orthometric heights of our study refer to the official state's benchmarks, belonging to the National Triangulation Network, maintained from the Hellenic Geographic Military Service. The total number of the used benchmarks is 12, covering an area of almost 450 km~2 (22.5 km × 20 km). The results confirm an improvement of the heights related standard deviation from 9.1 cm (official model) to 5.0 cm (parametric model), respectively. The new parametric model seems to widely absorb various systematic effects of the existing geodetic networks.