[GRASS-user] r.sun annual radiation

Markus Neteler neteler at osgeo.org
Tue Sep 6 13:53:36 EDT 2011

On Tue, Sep 6, 2011 at 7:20 PM, Salvatore Mellino
<salvatore.mellino at gmail.com> wrote:

> now I can't verify in which way the sun map made with arcGIS was done (albedo,
> atmospheric turbidity…) maybe the differences depend on terrain shadow effect
> that I have not considered in grass map.

Depending on your terrain that can make a huge difference.
See for example (Alpine region next to my home):

-> Solar radiation based on high resolution DEM

> If I want to add this effect to your script for global radiation, how can I do?

Just add the -s flag to r.sun.

> And moreover,  will your script calculate automatically  slope and aspect from DTM or it use the default values?

It calculates slope and aspect from DTM automatically.


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