#2081: r.sun (mode 2): sawtooth bug in diffuse irradiation map
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Reporter: hamish | Owner: grass-dev@…
Type: defect | Status: new
Priority: major | Milestone: 6.4.4
Component: Raster | Version: svn-develbranch6
Keywords: r.sun | Platform: Linux
Cpu: x86-64 |
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Hi,
in investigating #2014 I noticed there's a bug in the calculation for
diffuse sunlight when the sun is at low angles to the horizon. the overall
trend seems ok, but there's a sawtooth pattern which follows the curvature
of the lines of latitude.
The attached screenshots are for Ross Island in Antarctica, epsg:3286
bounds:
{{{
north: 1437000
south: 1341000
west: 17000
east: 119000
res: 100
}}}
?
made with:
{{{
DAY=060
r.sun -s elevin=etopo1.ross_island step=0.05 \
beam_rad=erebus.direct.$DAY diff=erebus.diffuse.$DAY day=$DAY
}}}
thanks,
Hamish
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Ticket URL: <https://trac.osgeo.org/grass/ticket/2081>
GRASS GIS <http://grass.osgeo.org>