Airborne Laser Scanning
1st project cycle (2017 – 2023) and creation of DTM 5.0
Since 2017, the Geodesy, Cartography and Cadastre Authority of the Slovak Republic (ÚGKK SR) was preparing (in a contractor manner) a new Digital Terrain Model (DTM 5.0) of the entire territory of the Slovak Republic created from Airborne laser scanning (ALS) data. In May 2023, the 1st cycle of the ALS project was completed by making the seamless DTM 5.0 of the entire territory of Slovakia available to the public.
In the 1st cycle of the project, the territory of Slovakia was divided into 42 sites (lots). The scanning was carried out in the vegetation-free winter period gradually from the west to the east of Slovakia.
- Overview of lots in Shapefile format (1st ALS project cycle)
- Overview of parameters of available lots (1st ALS project cycle)
- Overview of LAS file footprints (1st ALS project cycle)
Provision of ALS products
Products of Airborne Laser Scanning DTM 5.0 a DSM 1.0 in coordinate system S-JTSK(JTSK03) and vertical system Bpv are freely available in TIFF raster format for download through the cloud.
| Products of 1st ALS project cycle to download from cloud | |||||
|---|---|---|---|---|---|
| DTM 5.0 | ZIP (183 GB) | ||||
| DSM 1.0 | ZIP (138 GB) | ||||
Due to the large volume of data (several TB), the Classified Point Clouds are still provided in an offline mode on a lot-by-lot basis through the customer centres - Bratislava (Chlumeckého 4) and Prešov (Suvorovova 2).
If you are interested in obtaining Classified Point Cloud, please complete the order form and deliver it to the contact address here:
Smaller volume data (sections) (DTM 5.0 and DSM 1.0 to 400 km2, Classified Point Cloud to 2 km2) can be downloaded via the Map Client ZBGIS application, more information here.
When creating their own work and publishing it, the users are obliged to indicate the source of ALS Products as follows: "ÚGKK SR". The provided Products are subject to the Terms and Conditions of the Provision and Use of Airborne Laser Scanning Products.
Table of approximate ALS product file sizes is available for download here.
DTM 5.0 in application Map client ZBGIS:
Point clouds in application Map client ZBGIS in 3D view:
Tutorials to help you work with ALS Products can be found at the following links:
- How to work with DTM in QGIS application (Slovak only)
- How to work with point cloud in QGIS application (Slovak only)
- How to unpack LAZ format to LAS format using LASzip (Slovak only)
2nd project cycle (2022 – 2026) and creation of DTM 6.0
Since 2022, ÚGKK SR has been updating the ALS Products within the 2nd cycle of ALS data collection on selected parts of Slovakia, again in a contractor manner. Subsequently, the Digital Terrain Model (DTM 6.0) and the Digital Surface Model (DSM 2.0) will be processed from the delivered classified point cloud by ÚGKK SR. In principle, the entire 2nd cycle of the ALS project will be divided into 3 parts (4-year periods).
The whole territory of Slovakia is divided into 73 lots. The scanning of selected lots is again carried out in the vegetation-free winter period from the west of Slovakia to the east.
Comparison of basic information and required parameters of 1st and 2nd cycle
|
|
1st ALS Cycle (DTM 5.0) |
2nd ALS Cycle (DTM 6.0) |
|
Cycle duration: |
5 years (1 FD) |
12 years (3 FA) |
|
Number of FA participants: |
5 |
4 |
|
Final ALS products: |
classified point clouds DTM |
classified point clouds |
|
ALS lots (area): |
900 to 1800 km2 |
500 to 900 km2 |
|
Total number of lots: |
42 |
73 |
|
ALS period: |
vegetation free season (from 01.11. to 30.4.) |
vegetation free season (from 15.10. to 15.4.) |
|
Last reflection point density (lrp): |
min. 5 lrp/m2 |
min. 15 lrp/m2 |
|
Beam trace: |
max. 0,25 m |
max. 0,45 m |
|
Overlap of swaths: |
< 20% |
< 40% |
|
Transverse swaths: |
1 for each flight |
min. 3 per lot |
|
Classification of point clouds into classification classes: |
compulsory - 2 classification classes optional - 10 classification classes |
compulsory - 10 classification classes optional – Power lines (Wire) and Tower |
|
Verticalaccuracy of cloud points: |
mh ≤ 0,11 m |
mh ≤ 0,10 m |
|
Positional accuracy of cloud points: |
mXY ≤ 0,30 m |
mXY ≤ 0,20 m |
According to the schedule, the updated ALS Products from the first lots (no. 04, 06, 07, 10, 20) will be available to the public in spring 2024.