I am a software developer working on a strategy game in my spare time as a hobby. I still have very little knowledge of and experience with Geographic Information Systems and the different file formats, so please bear with me.

I am interested in using real-world maps as the stage for my game and have been investigating several online map data services to see if I could download an elevation map and convert it to raw data for my game maps. For example it could be nice to have an elevation map of the southern part of Africa for instance (nice simple cone shape).

For my purposes, the map data only needs to live up to the following:

  1. Depth of 8-bit, so between 0-255 values
  2. Elevation below sea level is not needed (sea level = 0)
  3. Low resolution, at best 1 kilometer, but 10 kilometer is fine too

I am ready to investigate many of the file formats offered to be able to do so. However, since I am just at the experimental stage, I am wondering whether there aren't already some files like that available, e.g. in *.BMP format.

P.S.: I am also open for fictional or procedurally generated maps to play around with.

  • 2
    If you are seeking open data then I think the place to ask is the Open Data Stack Exchange.
    – PolyGeo
    Commented Apr 13, 2018 at 8:51
  • I know where to get open data, I just would like to know how to get it in the format that I seek. Commented Apr 13, 2018 at 10:44
  • Apparently, Google Maps has a neat API that may be useful. Commented Apr 13, 2018 at 10:44
  • If you "know where to get open data" then what format do you have your data in? It sounded like you were still looking for data.
    – PolyGeo
    Commented Apr 13, 2018 at 10:47
  • Maybe you missed this part: "...have been investigating several online map data services..." Commented Apr 13, 2018 at 12:26

2 Answers 2


Free Digital Terrain Models (DTM, these show the real surface height of the earth) are rare. But you can download the Digital Surface Model (DSM, showing the solid objects closest to the sensor, e.g. building, forest, etc) procurred by the SRTM mission done by NASA here: https://www2.jpl.nasa.gov/srtm/cbanddataproducts.html

  • Thanks! However, almost all the links on that page are dead. :-( Commented Apr 13, 2018 at 9:10
  • Looking at Photojournal now, which looks promising. Commented Apr 13, 2018 at 9:11

There is a project from NASA and the project name is Shuttle Radar Topography Mission (SRTM) and there you can find 90 m resolution topological raster.

on top of that you can improve the topology with use of QGIS

Examples of improvement -

Original image of an area of 1 Ha enter image description here

improved image of the same area enter image description here

and you can improve this further because not as images the topological maps have continuity. as well as you can easily change the bit depth for your suiting with the use of QGIS with in 15 minutes.

Links -

Google Earth Engine

NASA's Page

You can download images of any place of the world from this LINK

  • please let me know if you need details on how to smooth the 90m resolution image to smoother resolution and change the bit depth Commented Jan 24, 2021 at 9:13

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