1i.eb.netrad(1)                Grass User's Manual               i.eb.netrad(1)
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NAME

6       i.eb.netrad  - Net radiation approximation (Bastiaanssen, 1995).
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KEYWORDS

9       imagery, energy balance, net radiation, SEBAL
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SYNOPSIS

12       i.eb.netrad
13       i.eb.netrad --help
14       i.eb.netrad  albedo=name  ndvi=name  temperature=name localutctime=name
15       temperaturedifference2m=name   emissivity=name   transmissivity_single‐
16       way=name  dayofyear=name sunzenithangle=name output=name  [--overwrite]
17       [--help]  [--verbose]  [--quiet]  [--ui]
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19   Flags:
20       --overwrite
21           Allow output files to overwrite existing files
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23       --help
24           Print usage summary
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26       --verbose
27           Verbose module output
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29       --quiet
30           Quiet module output
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32       --ui
33           Force launching GUI dialog
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35   Parameters:
36       albedo=name [required]
37           Name of albedo raster map [0.0;1.0]
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39       ndvi=name [required]
40           Name of NDVI raster map [-1.0;+1.0]
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42       temperature=name [required]
43           Name of surface temperature raster map [K]
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45       localutctime=name [required]
46           Name of time of satellite overpass raster map [local time in UTC]
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48       temperaturedifference2m=name [required]
49           Name of the difference map of  temperature  from  surface  skin  to
50           about 2 m height [K]
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52       emissivity=name [required]
53           Name of the emissivity map [-]
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55       transmissivity_singleway=name [required]
56           Name of the single-way atmospheric transmissivitymap [-]
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58       dayofyear=name [required]
59           Name of the Day Of Year (DOY) map [-]
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61       sunzenithangle=name [required]
62           Name of the sun zenith angle map [degrees]
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64       output=name [required]
65           Name of the output net radiation layer
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DESCRIPTION

68       i.eb.netrad calculates the net radiation at the time of satellite over‐
69       pass, the way it is in the SEBAL  model  of  Bastiaanssen  (1995).   It
70       takes  input  of Albedo, NDVI, Surface Skin temperature, time of satel‐
71       lite overpass, surface emissivity, difference of temperature from  sur‐
72       face  skin  and about 2 m height (dT), instantaneous satellite overpass
73       single-way atmospheric transmissivity (tsw), Day of Year (DOY), and sun
74       zenith angle.
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NOTES

77       In  the old methods, dT was taken as flat images (dT=5.0), if you don’t
78       have a dT map from ground data, you would want to try something in this
79       line,  this  is  to calculate atmospherical energy balance. In the same
80       way, a standard tsw is used in those equations. Refer  to  r_net.c  for
81       that  and for other non-used equations, but stored in there for further
82       research convenience.
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TODO

85       Add more explanations.
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SEE ALSO

88        i.eb.soilheatflux, i.eb.hsebal01, i.albedo
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REFERENCES

91           ·   Bastiaanssen, W.G.M., 1995.  Regionalization  of  surface  flux
92               densities  and  moisture  indicators  in  composite  terrain; a
93               remote sensing approach under clear skies in mediterranean cli‐
94               mates.  PhD  thesis, Wageningen Agricultural Univ., The Nether‐
95               land, 271 pp.  (PDF)
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97           ·   Chemin, Y., 2012.  A  Distributed  Benchmarking  Framework  for
98               Actual  ET  Models,  in:  Irmak, A. (Ed.), Evapotranspiration -
99               Remote Sensing and Modeling. InTech.  (PDF)
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AUTHOR

102       Yann Chemin, International Rice Research Institute, The Philippines
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SOURCE CODE

105       Available at: i.eb.netrad source code (history)
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107       Main index | Imagery index | Topics index | Keywords index |  Graphical
108       index | Full index
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110       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual
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114GRASS 7.8.2                                                     i.eb.netrad(1)