<div dir="ltr">Hi Antonio<div>Thank you for setting out an approach. I will need to consider what to do as scripting is out of my league. </div><div>If you are available/interested on freelance basis for this sort of thing, please contact me off the message list to discuss. </div>
<div>Kind regards</div><div>Angus</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On 24 September 2013 15:32, Antonio Falciano <span dir="ltr"><<a href="mailto:afalciano@yahoo.it" target="_blank">afalciano@yahoo.it</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Il 24/09/2013 13:26, Angus Jeffery ha scritto:<br>
<div class="im">> Hi Antonio<br>
> Thanks for your reply. Very interesting despite my lack of Italian and I<br>
> can see some application for your research.<br>
> However, it's not quite what I meant - what I want to try to do is work<br>
> out which part of a defined site (I have a polygon) is least (or most)<br>
> visible from the surrounding landscape within a defined radius (I have<br>
> raster of elevation data). Any ideas?<br>
<br>
</div>Hi Angus,<br>
I'd convert the polygon into a set of equispaced points using e.g. the<br>
SEXTANTE "Create graticule" tool (to be clipped). The distance to adopt<br>
should be the DEM cell size. Each point can be considered as a single<br>
target and then be used for the computation of a binary viewshed in<br>
order to understand from where it's visible within the search radius.<br>
The number of pixels of the binary viewshed whose value is equal to 1<br>
(i.e. the sum of all the values within the search radius) will represent<br>
the score of each point. Higher is the score, more visible from<br>
different places the point will be. It could be calculated with the<br>
SEXTANTE "Basic statistics" tool.<br>
The complex part is that we have to iterate over all the points and for<br>
sure the best approach is to do it programmatically, e.g. with some<br>
BeanShell scripting under SEXTANTE or Bash/Python under GRASS GIS.<br>
<br>
Cheers,<br>
Antonio<br>
<div class="HOEnZb"><div class="h5"><br>
--<br>
Antonio Falciano<br>
<a href="http://www.linkedin.com/in/antoniofalciano" target="_blank">http://www.linkedin.com/in/antoniofalciano</a><br>
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