[GRASS-user] Re: DGN: LoS [was] grass

[H.S.Rai]

On Wednesday 24 October 2007, ec.jkd at tpcsed.com wrote:

> > On a contour map i want to plot two points A an B .The requirment is to
> > know if point A has a line of sight with point B. For this i started with
> > r.contour but this only gives me ontour of pheripheral i.e only the outline
> > and not the actual contour map with different heights. Now what i want from
> > you is firslty how shoulsd i produce first contour map and then find line
> > of sight.


Import your "56k.gdn":

 v.in.ogr -z dsn=56k.dgn output=dgn

Change region as per your requirement:

 g.region vect=dgn

or

 g.region n=22000 s=-2400 e=11000 w=-22000


Convert vector to raster:

 v.to.rast input=dgn output=dgnRas use=attr column=Level

Produce DEM:

r.surf.contour input=dgnRas output=dgnDTM

r.los give you viewshed, not visibility between two point, as such.

You may also try d.profile

All the dest,

-- 
H.S.Rai
http://hs.raiandrai.com/