[GRASS-user] Re: Re: How to estimate viewable area from the top of tha mountain...

Dear grass users

I wish to express my gratitude for information on 'r.los'.

Neither r.los nor r.viewshed considered the surface of the sea.
Because I had wanted to include the surface of the sea, the null value
was converted into 0 by using r.mapcalc. The result was excellent.

And....are these modules computable in two or more points?...I'll try it.

Best

Yasuo shimada (Japan Weather Association)

----- Original Message -----

Date: Fri, 8 Jul 2011 11:40:18 +0900 (JST)
From: sgw00412@nifty.com
To: grass-user@lists.osgeo.org
Subject: Re: How to estimate viewable area from the top of tha mountain...

Sorry, now I find r.viewshed of grass add-on.

Yasuo shimada

----- Original Message -----

Date: Fri, 8 Jul 2011 11:22:09 +0900 (JST)
From: sgw00412@nifty.com
To: grass-user@lists.osgeo.org
Subject: How to estimate viewable area from the top of tha mountain...

Dear grass user

I'm looking for a grass command that unobstructed view area at one station.

For example...
I want to estimate the veiwable area around the top, when I am in the top of

a

mountain. It looks like simple, but I cannot see the opponent if there is a

b

arrier in front of my position.

In bird survey ( bird count in fixed station ), investigator's observation a

r

e

a (or viewable area) is very important....

Is there a grass command that calcurates viewable area, when altitude dem (r

a

s

t) and the observation point (vect or rast) are given ...?

Best

Yasuo shimada ( Japan weather Association )