NAME
i.sunhours - Creates a sunshine hours map.
KEYWORDS
sunshine, hours, daytime
SYNOPSIS
i.sunhours
i.sunhours help
i.sunhours dayofyear=name latitude=name output=name [--overwrite] [--verbose] [--quiet]
Flags:
- --overwrite
- Allow output files to overwrite existing files
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- dayofyear=name [required]
- Name of the day of year input map
- latitude=name [required]
- Name of the latitude input map
- output=name [required]
- Name of the output sunshine hours map
DESCRIPTION
i.sunhours creates a sunshine hours map from any map, it
considers a perfect clear day. This method follows Iqbal (1983)
as found in the AHAS manual (Parodi, 2000).
The latitude input map can be created with the i.latlong
module, or with r.mapcalc's y() function in a
latitude-longitude location (possibly reprojected with r.proj.
REFERENCES
Iqbal, M., 1983. An Introduction to Solar Radiation. Iqbal, M.,
Editorial: Academic Press. Toronto, Canada.
Parodi, G., 2000. AVHRR Hydrological Analysis System. Algorithms
and Theory, Version 1.0. WRES - ITC, The Netherlands.
SEE ALSO
i.evapo.TSA,
i.latitude
AUTHOR
Yann Chemin, GRASS Development Team
Last changed: $Date: 2011-11-08 13:24:20 -0800 (Tue, 08 Nov 2011) $
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