Digital relief model of the Slovak Republic

The Geodesy, Cartography and Cadastre Authority of Slovak Republic (ÚGKK SR) has been preparing a new digital model of relief the fifth generation for the whole territory of the Slovak Republic since 2017. The whole territory of Slovakia is divided into 42 sections. Together with MILAN Geoservice GmbH we were among the five participants of the framework agreement. Individual sections are assigned based on an open competition among these participants. The project is expected to be completed in 2023.

The data are collected by aerial laser scanning. The resulting product then consists in complete processing of the point cloud – from data reconciliation and georeferencing to data classification – at a minimum density of 15 points per m² (last echo points) with a height accuracy of ≤ 0.11 m and a positioning accuracy of cloud ≤ 0.30 m. The cloud is classified into 10 classes, and quality control of the classified cloud is then carried out so as to meet the classification requirements i.e.confidence level of more than 99.5 % for the “ground” class and more than 90% for other classes.

The digital relief model itself will be supplied in the form of GRID with a resolution of 1 x 1 meter, which is created by interpolation from the classified point cloud.

In the course of several stages of this project, we are so far processing an area of more than 8,600 km². One of the most important sections of this project is formed by part of the Tatra Mountains, where the elevation difference of the terrain reaches several hundred meters of altitude. This area is covered with snow for a large part of the year so it was necessary to plan the flights so that the locations were free of snow and we could ensure a good scan of all the ridges, valleys and relief details.

The delivered classified point cloud then becomes a part of the interactive web portal of ÚGKK, where ÚGKK provides LiDAR data free of charge. You can view the data at the website https://zbgis.skgeodesy.sk/mkzbgis/en/teren?bm=dmr&z=8&c=19.530000,48.800000#.