Using Computamaps terrain and clutter data

The free terrain and clutter data found on the Computamaps.com website is compatible with EDX software. Here are a few suggestions on using the data:

    Terrain Elevation Data (dtm folder)

  • Open the “projection” file in a text editor and make sure the first line is “GRS-1980” not “GRS-80”.
  • In the EDX Databases/Terrain dialog set the database type to “MSI-Planet” and the folder with the database is the DTM folder created when you unZIPped the file from Computamaps.

If you wish to use two or more Planet data files at the same time you will first need to convert them to our 201 format using the EDXCV conversion utility. The conversion type is for Terrain data and “MSI-Planet to EDX 201”. You will need to enter the appropriate parameters into the “Geographic parameters” dialog:

  • Transverse Mercator ref longitude is the second number in the fourth line of the “projection” file
  • ref latitude, standard parallel 1 and 2 are always 0
  • scale compression is 0.9996
  • false easting is 500000 false northing is 0 for data North of the equator and 10000000 for South of the equator
  • major axis is 6378137
  • flattening is 0.003352811
  • datum shifts are all 0

Once you have your 201 files, they should all be put in one folder on your hard drive and then use the “EDX Universal 201” terrain database type in the Databases/Terrain dialog.

Clutter Data (CLT folder) – Same method as for steps 1 & 2 in the terrain data above except the database type and location “CLT” folder entry is made from the Databases/Clutter dialog. If you wish to use two or more Planet data files at the same time you will first need to convert them to our .GCV format using the EDXCV conversion utility. The conversion type is for Land Use data and “MSI-Planet format to EDX GCV”. You will need to enter the appropriate parameters into the “Geographic parameters” dialog as described above. Once you have your GCV files, they should all be put in one folder on your hard drive and then use the “EDX .GCV format” type in the Databases/Land Use Please contact EDX technical support if you have further questions.