NAME
r.sun.hourly - Runs r.sun in loop for given time range within one day (mode 1 or 2)
KEYWORDS
raster,
solar,
sun energy,
parallel
SYNOPSIS
r.sun.hourly
r.sun.hourly --help
r.sun.hourly [-ctbpm] elevation=string [aspect=string] [slope=string] [linke=name] [linke_value=float] [albedo=name] [albedo_value=float] [coeff_bh=name] [coeff_bh_strds=name] [coeff_dh=name] [coeff_dh_strds=name] [lat=name] [long=name] mode=string start_time=float end_time=float [time_step=float] day=integer year=integer [civil_time=float] [distance_step=float] [beam_rad_basename=string] [diff_rad_basename=string] [refl_rad_basename=string] [glob_rad_basename=string] [incidout_basename=string] [beam_rad=string] [diff_rad=string] [refl_rad=string] [glob_rad=string] [solar_constant=float] [nprocs=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -c
- Compute cumulative raster maps of irradiation (only with mode 2)
- -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 irradiance rasters
- -p
- Do not incorporate the shadowing effect of terrain
- -m
- Use the low-memory version of the program
- --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-
- 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
- coeff_bh=name
- Name of real-sky beam radiation coefficient (thick cloud) input raster map [0-1]
- coeff_bh_strds=name
- Name of real-sky beam radiation coefficient (thick cloud) input space-time raster dataset
- coeff_dh=name
- Name of real-sky diffuse radiation coefficient (haze) input raster map [0-1]
- coeff_dh_strds=name
- Name of real-sky diffuse radiation coefficient (haze) input space-time raster dataset
- lat=name
- Name of input raster map containing latitudes [decimal degrees]
- long=name
- Name of input raster map containing longitudes [decimal degrees]
- mode=string [required]
- Select r.sun mode to choose between irradiance (mode 1) and irradiation (mode 2)
- Options: mode1, mode2
- Default: mode1
- mode1: r.sun mode 1 computes irradiance [W.m-2]
- mode2: r.sun mode 2 computes irradiation [Wh.m-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 calculations
- Options: 1900-9999
- Default: 1900
- civil_time=float
- Civil time zone value, if none, the time will be local solar time
- distance_step=float
- Sampling distance step coefficient (0.5-1.5)
- Default: 1.0
- beam_rad_basename=string
- Base name for output beam irradiance [W.m-2] (mode 1) or irradiation raster map [Wh.m-2] (mode 2)
- Underscore and time are added to the base name for each map
- diff_rad_basename=string
- Base name for output diffuse irradiance [W.m-2] (mode 1) or irradiation raster map [Wh.m-2] (mode 2)
- Underscore and time are added to the base name for each map
- refl_rad_basename=string
- Base name for output ground reflected irradiance [W.m-2] (mode 1) or irradiation raster map [Wh.m-2] (mode 2)
- Underscore and time are added to the base name for each map
- glob_rad_basename=string
- Base name for output global (total) irradiance [W.m-2] (mode 1) or irradiation raster map [Wh.m-2] (mode 2)
- Underscore and time are added to the base name for each map
- incidout_basename=string
- Base name for output incidence angle raster maps (mode 1 only)
- Underscore and time are added to the base name for each map
- beam_rad=string
- Output beam irradiation raster map [Wh.m-2] (mode 2) integrated over specified time period
- diff_rad=string
- Output diffuse irradiation raster map [Wh.m-2] (mode 2) integrated over specified time period
- refl_rad=string
- Output ground reflected irradiation raster map [Wh.m-2] (mode 2) integrated over specified time period
- glob_rad=string
- Output global (total) irradiation raster map [Wh.m-2] (mode 2) integrated over specified time period
- solar_constant=float
- Solar constant [W/m^2]
- If not specified, r.sun default will be used.
- nprocs=integer
- Number of r.sun processes to run in parallel
- Options: 1-
- Default: 1
r.sun.hourly is a convenient script for running
r.sun for multiple times in a loop. It allows to run r.sun in mode 1
to create maps of instantaneous solar irradiance.
Alternatively, it allows to integrate solar irradiance maps over specified time period
to compute solar irradiation (mode 2).
See r.sun
manual page for more information.
There are three basic types of output:
In mode 1, if one of options beam_rad_basename, diff_rad_basename
refl_rad_basename, glob_rad_basename, and incidout_basename
is selected, it will compute a time series of irradiance maps.
Optionally, b flag will convert them to binary rasters representing shaded areas.
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.
In mode 2, a series of
solar irradiation maps will be computed with units Wh/m2.
This is done by multiplying an instantaneous irradiance raster
computed in the middle of the specified intervals by time step.
For example, if start_time is 8, end_time is 10 and
time_step is 0.5, the irradiation rasters will be computed for
times 8:15, 8:45, 9:15 and 9:45.
If flag c is selected it will accumulate the irradiation
values, meaning the last raster represents all solar irradiation during the period.
When any of output options beam_rad, diff_rad
refl_rad and glob_rad are specified,
irradiation rasters are summed over the specified period (mode 2 only).
Real-sky radiation parameters (see
r.sun)
can be input as raster map (
coeff_bh and
coeff_dh),
or space-time raster dataset (
coeff_bh_strds and
coeff_dh_strds)
to account for time-varying conditions. The space-time raster
dataset (strds) needs to be interval-based (i.e. have start and end time,
see
t.register, for more details).
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
Calculate beam irradiation during day and also cumulative irradiation,
use different steps:
g.region raster=elevation res=100 -pa
r.sun.hourly elevation=elevation year=2019 day=100 start=8 end=16 time_step=0.333 beam_rad_basename=beam_m2_step_short mode=mode2 nprocs=4 -t
r.sun.hourly elevation=elevation year=2019 day=100 start=8 end=16 time_step=0.333 beam_rad_basename=beam_m2_step_short_cum mode=mode2 nprocs=4 -tc
r.sun.hourly elevation=elevation year=2019 day=100 start=8 end=16 time_step=1 beam_rad_basename=beam_m2_step_long mode=mode2 nprocs=4 -t
r.sun.hourly elevation=elevation year=2019 day=100 start=8 end=16 time_step=1 beam_rad_basename=beam_m2_step_long_cum mode=mode2 nprocs=4 -tc
g.gui.tplot strds=beam_m2_step_short,beam_m2_step_long,beam_m2_step_short_cum,beam_m2_step_long_cum coordinates=636919,220431
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.
r.sun,
r.sun.daily in Addons
Vaclav Petras,
NCSU OSGeoREL,
Anna Petrasova,
NCSU OSGeoREL
SOURCE CODE
Available at:
r.sun.hourly source code
(history)
Latest change: Thursday Sep 05 10:18:47 2024 in commit: 5762dd9aec83017ed4b745addec806dcf3c54976
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GRASS Development Team,
GRASS GIS 8.4.1dev Reference Manual