i.eb.netrad
Net radiation approximation (Bastiaanssen, 1995).
i.eb.netrad albedo=name ndvi=name temperature=name localutctime=name temperaturedifference2m=name emissivity=name transmissivity_singleway=name dayofyear=name sunzenithangle=name output=name [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
i.eb.netrad albedo=name ndvi=name temperature=name localutctime=name temperaturedifference2m=name emissivity=name transmissivity_singleway=name dayofyear=name sunzenithangle=name output=name
grass.script.run_command("i.eb.netrad", albedo, ndvi, temperature, localutctime, temperaturedifference2m, emissivity, transmissivity_singleway, dayofyear, sunzenithangle, output, overwrite=None, verbose=None, quiet=None, superquiet=None)
Example:
gs.run_command("i.eb.netrad", albedo="name", ndvi="name", temperature="name", localutctime="name", temperaturedifference2m="name", emissivity="name", transmissivity_singleway="name", dayofyear="name", sunzenithangle="name", output="name")
grass.tools.Tools.i_eb_netrad(albedo, ndvi, temperature, localutctime, temperaturedifference2m, emissivity, transmissivity_singleway, dayofyear, sunzenithangle, output, overwrite=None, verbose=None, quiet=None, superquiet=None)
Example:
tools = Tools()
tools.i_eb_netrad(albedo="name", ndvi="name", temperature="name", localutctime="name", temperaturedifference2m="name", emissivity="name", transmissivity_singleway="name", dayofyear="name", sunzenithangle="name", output="name")
This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.
Parameters
albedo=name [required]
Name of albedo raster map [0.0;1.0]
ndvi=name [required]
Name of NDVI raster map [-1.0;+1.0]
temperature=name [required]
Name of surface temperature raster map [K]
localutctime=name [required]
Name of time of satellite overpass raster map [local time in UTC]
temperaturedifference2m=name [required]
Name of the difference map of temperature from surface skin to about 2 m height [K]
emissivity=name [required]
Name of the emissivity map [-]
transmissivity_singleway=name [required]
Name of the single-way atmospheric transmissivitymap [-]
dayofyear=name [required]
Name of the Day Of Year (DOY) map [-]
sunzenithangle=name [required]
Name of the sun zenith angle map [degrees]
output=name [required]
Name of the output net radiation layer
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--qq
Very quiet module output
--ui
Force launching GUI dialog
albedo : str, required
Name of albedo raster map [0.0;1.0]
Used as: input, raster, name
ndvi : str, required
Name of NDVI raster map [-1.0;+1.0]
Used as: input, raster, name
temperature : str, required
Name of surface temperature raster map [K]
Used as: input, raster, name
localutctime : str, required
Name of time of satellite overpass raster map [local time in UTC]
Used as: input, raster, name
temperaturedifference2m : str, required
Name of the difference map of temperature from surface skin to about 2 m height [K]
Used as: input, raster, name
emissivity : str, required
Name of the emissivity map [-]
Used as: input, raster, name
transmissivity_singleway : str, required
Name of the single-way atmospheric transmissivitymap [-]
Used as: input, raster, name
dayofyear : str, required
Name of the Day Of Year (DOY) map [-]
Used as: input, raster, name
sunzenithangle : str, required
Name of the sun zenith angle map [degrees]
Used as: input, raster, name
output : str, required
Name of the output net radiation layer
Used as: output, raster, name
overwrite : bool, optional
Allow output files to overwrite existing files
Default: None
verbose : bool, optional
Verbose module output
Default: None
quiet : bool, optional
Quiet module output
Default: None
superquiet : bool, optional
Very quiet module output
Default: None
albedo : str | np.ndarray, required
Name of albedo raster map [0.0;1.0]
Used as: input, raster, name
ndvi : str | np.ndarray, required
Name of NDVI raster map [-1.0;+1.0]
Used as: input, raster, name
temperature : str | np.ndarray, required
Name of surface temperature raster map [K]
Used as: input, raster, name
localutctime : str | np.ndarray, required
Name of time of satellite overpass raster map [local time in UTC]
Used as: input, raster, name
temperaturedifference2m : str | np.ndarray, required
Name of the difference map of temperature from surface skin to about 2 m height [K]
Used as: input, raster, name
emissivity : str | np.ndarray, required
Name of the emissivity map [-]
Used as: input, raster, name
transmissivity_singleway : str | np.ndarray, required
Name of the single-way atmospheric transmissivitymap [-]
Used as: input, raster, name
dayofyear : str | np.ndarray, required
Name of the Day Of Year (DOY) map [-]
Used as: input, raster, name
sunzenithangle : str | np.ndarray, required
Name of the sun zenith angle map [degrees]
Used as: input, raster, name
output : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
Name of the output net radiation layer
Used as: output, raster, name
overwrite : bool, optional
Allow output files to overwrite existing files
Default: None
verbose : bool, optional
Verbose module output
Default: None
quiet : bool, optional
Quiet module output
Default: None
superquiet : bool, optional
Very quiet module output
Default: None
Returns:
result : grass.tools.support.ToolResult | np.ndarray | tuple[np.ndarray] | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None
will be returned. If an array type (e.g., np.ndarray) is used for one of the raster outputs, the result will be an array and will have the shape corresponding to the computational region. If an array type is used for more than one raster output, the result will be a tuple of arrays.
DESCRIPTION
i.eb.netrad calculates the net radiation at the time of satellite overpass, the way it is in the SEBAL model of Bastiaanssen (1995). It takes input of Albedo, NDVI, Surface Skin temperature, time of satellite overpass, surface emissivity, difference of temperature from surface skin and about 2 m height (dT), instantaneous satellite overpass single-way atmospheric transmissivity (tsw), Day of Year (DOY), and sun zenith angle.
NOTES
In the old methods, dT was taken as flat images (dT=5.0), if you don't
have a dT map from ground data, you would want to try something in this
line, this is to calculate atmospherical energy balance. In the same
way, a standard tsw is used in those equations. Refer to r_net.c
for
that and for other non-used equations, but stored in there for further
research convenience.
TODO
Add more explanations.
REFERENCES
- Bastiaanssen, W.G.M., 1995. Regionalization of surface flux densities and moisture indicators in composite terrain; a remote sensing approach under clear skies in mediterranean climates. PhD thesis, Wageningen Agricultural Univ., The Netherland, 271 pp. (PDF)
- Chemin, Y., 2012. A Distributed Benchmarking Framework for Actual ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and Modeling. InTech. (PDF)
SEE ALSO
i.eb.soilheatflux, i.eb.hsebal01, i.albedo
AUTHOR
Yann Chemin, International Rice Research Institute, The Philippines
SOURCE CODE
Available at: i.eb.netrad source code
(history)
Latest change: Thursday Jun 26 21:25:27 2025 in commit 3ec2b13