GRASS GIS manual: r.sun.hourly

NAME

r.sun.hourly - Runs r.sun in loop for given time range (mode 1)

KEYWORDS

SYNOPSIS

r.sun.hourly

r.sun.hourly --help

r.sun.hourly [-tb] elevation=string [aspect=string] [slope=string] [linke=name] [linke_value=float] [albedo=name] [albedo_value=float] start_time=float end_time=float [time_step=float] day=integer year=integer [civil_time=float] [beam_rad_basename=string] [diff_rad_basename=string] [refl_rad_basename=string] [glob_rad_basename=string] [incidout_basename=string] [nprocs=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-t: Register created series of output maps into temporal dataset; Dataset name is the same as the base name for the output series of maps
-b: Create binary rasters instead of irradiation rasters
--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

elevation=string [required]: Name of the input elevation raster map [meters]
aspect=string: Name of the input aspect map (terrain aspect or azimuth of the solar panel) [decimal degrees]
slope=string: Name of the input slope raster map (terrain slope or solar panel inclination) [decimal degrees]
linke=name: Name of the Linke atmospheric turbidity coefficient input raster map [-]
linke_value=float: A single value of the Linke atmospheric turbidity coefficient [-]; Options: 0.0-7.0; Default: 3.0
albedo=name: Name of the ground albedo coefficient input raster map [-]
albedo_value=float: A single value of the ground albedo coefficient [-]; Options: 0.0-1.0; Default: 0.2
start_time=float [required]: Start time of interval; Use up to 2 decimal places; Options: 0-24
end_time=float [required]: End time of interval; Use up to 2 decimal places; Options: 0-24
time_step=float: Time step for running r.sun [decimal hours]; Use up to 2 decimal places; Options: 0-24; Default: 1
day=integer [required]: No. of day of the year; Options: 1-365
year=integer [required]: Year used for map registration into temporal dataset or r.timestamp; This value is not used in r.sun calcluations; Options: 1900-9999; Default: 1900
civil_time=float: Civil time zone value, if none, the time will be local solar time
beam_rad_basename=string: Base name for output beam irradiance raster maps [Wh.m-2]; Underscore and day number are added to the base name for each map
diff_rad_basename=string: Base name for output diffuse irradiance raster maps [Wh.m-2]; Underscore and day number are added to the base name for each map
refl_rad_basename=string: Base name for output ground reflected irradiance raster maps [Wh.m-2]; Underscore and day number are added to the base name for each map
glob_rad_basename=string: Base name for output global (total) irradiance raster maps [Wh.m-2]; Underscore and day number are added to the base name for each map
incidout_basename=string: Base name for output incidence angle raster maps; Underscore and day number are added to the base name for each map
nprocs=integer: Number of r.sun processes to run in parallel; Options: 1-; Default: 1

DESCRIPTION
- Output parameters explanation
EXAMPLES
NOTE
SEE ALSO
AUTHOR

DESCRIPTION

r.sun.hourly is a convenient script for running r.sun for multiple times in a loop. It corresponds to mode 1 (instant mode, see r.sun manual page).

Output parameters explanation

Output is one or more series of irradiance raster maps. If flag b is checked the output is a series of binary maps. Using this flag in combination with beam_rad_basename is a convenient way to determine if there is direct sunlight or not at a certain place and time.

Series of maps are (if flag t is checked) registered to space time raster dataset with absolute time and point time (not interval time). Option year has to be specified so that the raster maps can be registered to space time dataset or assigned a timestamp. The reason is that it is not possible to assign time without date.

For GRASS 6, only timestamp is assigned.

EXAMPLES

Calculate for current region the beam irradiance (direct radiation) for DOY 355 in 2014 from 8am to 3pm:

g.region -p
r.sun.hourly elevation=elevation start_time=8 end_time=15 \
              day=355 year=2014 beam_rad_basename=beam nprocs=4 -t
# show information about newly created space time dataset
t.info beam

# show raster maps registered in beam temporal dataset
t.rast.list beam

NOTE

Beam irradiance binary raster maps can be displayed as semitransparent over other map layers or module r.null can be used to set one of the values (either shade or sunlight) as NULL.

AUTHOR

Vaclav Petras, NCSU OSGeoREL,
Anna Petrasova, NCSU OSGeoREL

Last changed: $Date: 2017-04-15 00:20:35 +0200 (Sat, 15 Apr 2017) $

SOURCE CODE

Available at: r.sun.hourly source code (history)