I am working on a project where I need to create viewshed areas around towers with a radius of 5000 meters. The underlying DEM I created using free Lidar data. Uptill now I did all this on a laptop with a core i7 proc and 8GBs of RAM. Pretty powerful but does not seem to be enough to complete the task within a reasonable timeframe.
Therefore I am considering the setup of a couple of virtual machines on AWS and I need input on what you guys out there would recommend in terms of resources: CPU, amount of RAM etc.
The process is the following:
- Merge DEM tiles into one huge TIFF that fully contains the DEM within 5000 m of the tower.
- Use this DEM (in TIFF) format in Grass 7.4 (r.viewshed) to generate the viewshed area.
- Vectorize the result viewshed raster and delete areas that have a DN value of 0 (not visible)
Even a smaller subset (a sector of 10°-20° from north) took half of the night to produce only the viewshed so I am kind of desperate to speed things up no matter what.