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

[sgw00412 at nifty.com]

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 at nifty.com
>To: grass-user at 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 at nifty.com
>>To: grass-user at 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 )