Terrain Data and Attribution

To work out how high a drone was above the ground, Dronetag needs to know how high the ground is. That comes from terrain models, maps of ground height published by survey agencies and space programmes. Some of them may only be used if you credit them. This page says what you need to keep when you pass exported data on.

What Terrain Data Is Used For

Terrain data gives the height above the ground (AGL) at every point.

It is also used for the sea-level altitude (MSL) in one case. When the drone reported no GPS height, Dronetag reads the ground height at the take-off point and adds the height above take-off.

Terrain Models

Dronetag can use the terrain models below. For each place it uses the most detailed one available.

Model	Covers	Detail	Measures	Credit needed
ČÚZK DMR 5G	Czechia	5 m	Bare ground	Yes
USGS 3DEP	United States	About 30 m	Bare ground	No
Copernicus DEM GLO-30	Most of Europe	30 m	Surface	Yes, with a disclaimer
NOAA ETOPO 2022	The whole world	About 1 to 2 km	Bare ground	No

The map shows which model is used where. Drag it to move around and use the buttons to zoom in. Click an area or a model name to see its details.

Click a coloured area or a model above to see its details.

The Copernicus models measure the top of trees and buildings. Over forest or in towns, the height above the ground reads low by about the height of the trees or roofs.

Where the Credits Are

An export carries credits only for the terrain it actually used, and only when that terrain needs a credit.

Format	Where to find the credits
CSV	The download is a zip with the CSV and ATTRIBUTION.txt. If no credit is needed, you get the plain CSV.
JSON	The attribution key at the end of the file
KMZ	The description of each flight's folder, under Terrain data
PDF	The Terrain Data section of the report

What ATTRIBUTION.txt Contains

ATTRIBUTION.txt is a short English text file in UTF-8. It names the CSV it belongs to and the columns whose values came from terrain data. These are alt_agl and alt_msl in CSV Telemetry, and max_alt_agl and max_alt_msl in CSV Summary. Then it lists each terrain model with three parts.

• The notice is the credit, word for word as the licence asks for it.
• The disclaimer appears only when the licence asks for one. Copernicus does.
• The licence line names the licence and links to it.

Lines are wrapped, but the wording never changes. A complete example is in ATTRIBUTION.txt.

Why the Credits Must Stay With the Data

The licences let you use and share the heights as long as the credit goes with them.

• Keep ATTRIBUTION.txt with the CSV when you send, upload or publish it.
• Keep the attribution block when you pass the JSON on.
• If you publish something built from these heights, such as a chart or a report, include the notice texts exactly as written. Some licences require the exact wording.

If you are unsure what a licence allows, read it through the link in the file or ask the data provider.