i downloaded the new (dutch hight data) AHN files, and was trying to perform a viewshed analysis at some point near UTRECHT.
The plugin (grass plugin) works ok, i tried it before with a dem map.
But when i use the AHN file it shows not the correct visibility area.
so my question is
- Does someone know how to setup the AHN files, for using in a viewshed analysis
- Does someone know how to make the real height information visible on a map