Try these free Open source Software GIS products.
or the Oxford Archaeology enhanced version of gvsig
On 07/12/2010 07:57, Andrew Smith wrote:
> I am sure this has been asked before, but am not sure where to look. I have tried 'Google' but could not really interpret what I was finding.
> I am interested in determining if intervisibility exists between various sites in SW England and S Wales, and am wondering if there are simple GIS systems, either free or inexpensive, available which can be run on a home pc.
> Any suggestions would be most welcome. I am aware of the graphical technique, but am looking at distances of possibly up to 60 km, and it gets a bit unhandy over those distances, the contours are not always legible in built-up areas, even at 1:25000, and I am also not sure over what distances the curvature of the earth starts to be critical.
> Many thanks in advance,
> Andrew Smith.