1i.aster.toar(1)             GRASS GIS User's Manual            i.aster.toar(1)
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NAME

6       i.aster.toar     -    Calculates   Top   of   Atmosphere   Radiance/Re‐
7       flectance/Brightness Temperature from ASTER DN.
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KEYWORDS

10       imagery, radiometric conversion, radiance, reflectance, brightness tem‐
11       perature, satellite, ASTER
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SYNOPSIS

14       i.aster.toar
15       i.aster.toar --help
16       i.aster.toar [-rabcde] input=name[,name,...] dayofyear=float sun_eleva‐
17       tion=float output=name  [--overwrite]  [--help]  [--verbose]  [--quiet]
18       [--ui]
19
20   Flags:
21       -r
22           Output is radiance (W/m2)
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24       -a
25           VNIR is High Gain
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27       -b
28           SWIR is High Gain
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30       -c
31           VNIR is Low Gain 1
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33       -d
34           SWIR is Low Gain 1
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36       -e
37           SWIR is Low Gain 2
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39       --overwrite
40           Allow output files to overwrite existing files
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42       --help
43           Print usage summary
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45       --verbose
46           Verbose module output
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48       --quiet
49           Quiet module output
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51       --ui
52           Force launching GUI dialog
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54   Parameters:
55       input=name[,name,...] [required]
56           Names of ASTER DN layers (15 layers)
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58       dayofyear=float [required]
59           Day of Year of satellite overpass [0-366]
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61       sun_elevation=float [required]
62           Sun elevation angle (degrees, < 90.0)
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64       output=name [required]
65           Base name of the output layers (will add .x)
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DESCRIPTION

68       i.aster.toar  calculates  the  Top  Of Atmosphere (TOA) reflectance for
69       Terra-ASTER L1B in the visible, NIR and  SWIR  bands  (9+1  bands)  and
70       brightness  temperature  for  the  TIR bands (5 bands), all from L1B DN
71       values.  It is useful to apply after import of original  ASTER  imagery
72       that is generally in standard DN values range.
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74       The order of input bands is
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76           •   VNIR: 1,2,3N,3B
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78           •   SWIR: 4,5,6,7,8,9
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80           •   TIR: 10,11,12,13,14
81       in one comma-separated list.
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NOTES

84       Internally,  a  gain code is defined to modify gains according to spec‐
85       tral bands following the GeoSystems GmbH  ATCOR  Ver.  2.0  Calibration
86       Files.  The function is defined in gain_aster.c file.
87       /*Gain Code*/
88           /*0 - High (Not Applicable for band 10-14: TIR)*/
89           /*1 - Normal*/
90           /*2 - Low 1(Not Applicable for band 10-14: TIR)*/
91           /*3 - Low 2(Not Applicable for Band 1-3N/B and 10-14)*/
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SEE ALSO

94        i.landsat.toar, r.in.aster
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96       ASTER sensor data download: ASTER: Advanced Spaceborne Thermal Emission
97       and Reflection Radiometer
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AUTHOR

100       Yann Chemin, CSU, Australia
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SOURCE CODE

103       Available at: i.aster.toar source code (history)
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105       Accessed: Saturday Jan 21 21:16:34 2023
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107       Main index | Imagery index | Topics index | Keywords index |  Graphical
108       index | Full index
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110       © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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114GRASS 8.2.1                                                    i.aster.toar(1)
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