[GRASS-user] r.los questions

[Brad Douglas]

On Mon, 2007-07-30 at 11:57 +0300, atlasis at telecom.ntua.gr wrote:
> On Mon, July 30, 2007 02:12, Brad Douglas wrote:
> > On Sun, 2007-07-29 at 18:54 +0300, atlasis at telecom.ntua.gr wrote:
> >
> >> 2. Is there a similar module, or a way using r.los, to compute los
> >> coverage in a specific altitude above the ground (i.e. 2000m)?
> >
> > r.los obs_height=2000 in=in_map out=out_map coord=x,y
> >
> > option "obs_height" is your height above ground.
> 
> "obs_height" corresponds to the the height of the "antenna", right? I
> mean, it corresponds to the altitude from which the observer "looks" at
> the area, correct?

Correct.  In this case the observer is an antenna.

> If yes, I'm interested in computing the los coverage in a specific
> altitude above the ground for all the surrounding area (i.e., if an
> aircraft flies at 5000ft above the ground, I want to compute the los
> coverage from the observing point at this altitude level to check if the
> aircraft is in the los coverage).

r.los is not the best piece of software to model antenna/RF links.  It
does not take Fresnel effects, antenna orientation, or pattern into
account.

I added dirty support for 1st Order Fresnel effects for a couple UHF
bands some time ago, but it needs a lot more work if I'm going to
release it as a module.  It did what I needed it to do and nothing more.


-- 
73, de Brad KB8UYR/6 <rez touchofmadness com>