[R-sig-Geo] Visibility Analysis in R

[Barry Rowlingson]

On Sat, Apr 21, 2012 at 1:38 PM, Raphael Fuhrer
<raphael.fuhrer at gmail.com> wrote:
> Dear all
>
> Does anybody know if it is possible to conduct a visibility analysis in R?
> I have
> - a large set of points = observer points
> - a digital surface model as an ascii grid
> - a set of points and polygons defining an amount of grid cells of interest
> For every individual observer point, the task is to check how many cells of interest are visible.
>
> Since the number of observer points is limited to 8 in ArcGIS and calculation time is far too long, I decided to use R. Unfortunately, I could not find any helpful packages or information on the internet.

 I suspect your best option is to use GRASS-GIS, and there is a
package for R-GRASS integration but I don't know much about it:

http://cran.r-project.org/web/packages/spgrass6/index.html

The relevant GRASS module is r.viewshed (r here stands for raster, not R):

http://grass.osgeo.org/manuals/html70_user/r.viewshed.html

Free and open source, of course it is!

Barry