1i.aster.toar(1) GRASS GIS User's Manual i.aster.toar(1)
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6 i.aster.toar - Calculates Top of Atmosphere Radiance/Re‐
7 flectance/Brightness Temperature from ASTER DN.
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10 imagery, radiometric conversion, radiance, reflectance, brightness tem‐
11 perature, satellite, ASTER
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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]
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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,...]Â [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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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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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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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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100 Yann Chemin, CSU, Australia
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103 Available at: i.aster.toar source code (history)
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105 Accessed: Mon Jun 20 16:47:25 2022
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107 Main index | Imagery index | Topics index | Keywords index | Graphical
108 index | Full index
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110 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
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114GRASS 8.2.0 i.aster.toar(1)