[GRASS-user] r.sun for selected points

[Tyler Smith]

On Thu, Aug 14, 2014, at 02:29 PM, Vaclav Petras wrote:


On Wed, Aug 13, 2014 at 4:46 PM, Tyler Smith
<[1]tyler at plantarum.ca> wrote:

I'm trying to generate solar irradiance data for a set of
points (which

requires r.horizon and r.sun output). My data covers most of
eastern

North America at 20m by 20m resolution. This is beyond the
capacity of

my computer to process. However, I don't need complete maps for
this

area. I only need the beam values for ca. 10,000 point
locations. I

expect it would be possible to do this on my laptop, but I
can't figure

out how to limit the analysis to these spots. Is it possible?
Does

anyone have any suggestions?


I'm not sure if I see all the details but if you can script in
Python or Bash you can do something like iteration over all
points using PyGRASS or v.out.ascii and textual processing (the
later applies also for external files with points) and then set
computation region using g.region around each point to
sufficient extent. Then you compute the r.horizon and r.sun
just in the specified (computational) region and store the
results as maps and as text (using e.g. r.univar or
v.what.rast). Does this make sense?



Thanks, Vaclav.



That makes sense. I know enough bash to try that out.



Best,



Tyler

References

1. mailto:tyler at plantarum.ca
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