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Ho yes, why not. I could use r.viewshed to find the farest part of
the topography able to see my point and get it's angle mode. The
trick to find is how to get that cell ?<br>
Best regards,<br>
frank<br>
<br>
<div class="moz-cite-prefix">Le 30/07/2018 à 11:18,
<a class="moz-txt-link-abbreviated" href="mailto:balotti.and@gmail.com">balotti.and@gmail.com</a> a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:fedb614a-1e9a-93ef-924f-fbfc59cf5581@gmail.com">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Il 30/07/2018 09:24, Frank David ha scritto:<br>
<blockquote type="cite"
cite="mid:05019a23-5d5e-bb04-809c-ed375a5e53f1@geophom.fr">
<meta http-equiv="Content-Type" content="text/html;
charset=utf-8">
Hi Andrea,<br>
Thanks for your message. But what is the ground plane ?
r.horizon use the topography, so nothing is plane (and the earth
curvature tends to lower the ground). </blockquote>
Yes, what you explain below is what I mean with "ground plane".<br>
<blockquote type="cite"
cite="mid:05019a23-5d5e-bb04-809c-ed375a5e53f1@geophom.fr">I
guess as the calculation is done at ground level, the minimum
viewable horizon cannot be lower than zero. The calculation
should be done higher than ground level to "see" negatives
horizon.</blockquote>
Have you taken a look to r.viewshed? I never tried it but maybe is
useful for your purposes.<br>
<blockquote type="cite"
cite="mid:05019a23-5d5e-bb04-809c-ed375a5e53f1@geophom.fr">Never
mind I will try to create my own r.horizon with r.transect or
r.profile.<br>
Best regards,<br>
Frank<br>
</blockquote>
Best regards,<br>
Andrea<br>
<br>
<blockquote type="cite"
cite="mid:05019a23-5d5e-bb04-809c-ed375a5e53f1@geophom.fr">
<div class="moz-cite-prefix">Le 30/07/2018 à 08:47, <a
class="moz-txt-link-abbreviated"
href="mailto:balotti.and@gmail.com" moz-do-not-send="true">balotti.and@gmail.com</a>
a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:71401a24-864c-09b0-3710-3634f9f001e8@gmail.com">Hi
Frank, <br>
just my opinion but r.horizon I suppose is targeted to solar
radiation modules and because of that returns only the
line-of-sight "obstacles" above the ground plane, where direct
sunlight may be obstructed by obstacles. <br>
best regards, <br>
<br>
Andrea Balotti <br>
<br>
Il 28/07/2018 15:59, Frank David ha scritto: <br>
<blockquote type="cite">Dear all, <br>
<br>
It seems that r.horizon in does not return negative heights.
How it's possible in case of the given point from the
calculation is done is located on mountain and the horizon
around is below zero ??. I miss something may be... <br>
<br>
Thank you for your explanations <br>
<br>
Regards <br>
<br>
Frank </blockquote>
</blockquote>
</blockquote>
<br>
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