i.eb.netrad(1grass) | GRASS GIS User's Manual | i.eb.netrad(1grass) |
i.eb.netrad - Net radiation approximation (Bastiaanssen, 1995).
imagery, energy balance, net radiation, SEBAL
i.eb.netrad
i.eb.netrad --help
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] [--help] [--verbose] [--quiet]
[--ui]
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.
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.
Add more explanations.
i.eb.soilheatflux, i.eb.hsebal01, i.albedo
Yann Chemin, International Rice Research Institute, The Philippines
Available at: i.eb.netrad source code (history)
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