Grass GIS has built-in support for line of sight analysis (the command is called r.los).
I'm revisiting an older post (Mountain Hiking Tracks in Făgăraș) that I've ended with a line of sight diagram I've built by hand based on the description given by a fellow hiker who described to us what we were seeing (peak names). This time I've used Grass GIS to build the line of sight raster from Vânătoarea lui Buteanu peak with a 20 Km radius. The background is based on the freely available Landsat 7 image data.
Note there are NULL values (failures to read altitudes in certain raster cells) in the SRTM data (represented in black in the picture below) so the line of sight analysis above was carried on an interpolated version of the data.
As far as I can tell, the diagram is fairly accurate. I'm not sure about "Turnul Paltinului" and the small ridge following it, but the rest of the features fall into place pretty nicely.
This is a photo taken from Vânătoarea lui Buteanu towards Negoiu Peak:
And this is a mash-up of the line of sight diagram over-imposed on the photograph:
I'm revisiting an older post (Mountain Hiking Tracks in Făgăraș) that I've ended with a line of sight diagram I've built by hand based on the description given by a fellow hiker who described to us what we were seeing (peak names). This time I've used Grass GIS to build the line of sight raster from Vânătoarea lui Buteanu peak with a 20 Km radius. The background is based on the freely available Landsat 7 image data.
