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

NAME
       i.aster.toar     -    Calculates   Top   of   Atmosphere   Radiance/Re-
       flectance/Brightness Temperature from ASTER DN.

KEYWORDS
       imagery, radiometric conversion, radiance, reflectance, brightness tem-
       perature, satellite, ASTER

SYNOPSIS
       i.aster.toar
       i.aster.toar --help
       i.aster.toar [-rabcde] input=name[,name,...] dayofyear=float sun_eleva-
       tion=float output=name  [--overwrite]  [--help]  [--verbose]  [--quiet]
       [--ui]

   Flags:
       -r
           Output is radiance (W/m2)

       -a
           VNIR is High Gain

       -b
           SWIR is High Gain

       -c
           VNIR is Low Gain 1

       -d
           SWIR is Low Gain 1

       -e
           SWIR is Low Gain 2

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       input=name[,name,...] [required]
           Names of ASTER DN layers (15 layers)

       dayofyear=float [required]
           Day of Year of satellite overpass [0-366]

       sun_elevation=float [required]
           Sun elevation angle (degrees, < 90.0)

       output=name [required]
           Base name of the output layers (will add .x)

DESCRIPTION
       i.aster.toar  calculates  the  Top  Of Atmosphere (TOA) reflectance for
       Terra-ASTER L1B in the visible, NIR and  SWIR  bands  (9+1  bands)  and
       brigthness  temperature  for  the  TIR bands (5 bands), all from L1B DN
       values.  It is useful to apply after import of original  ASTER  imagery
       that is generally in standard DN values range.

       The order of input bands is

           •   VNIR: 1,2,3N,3B

           •   SWIR: 4,5,6,7,8,9

           •   TIR: 10,11,12,13,14
       in one comma-separated list.

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

SEE ALSO
        i.landsat.toar, r.in.aster

       ASTER sensor data download: ASTER: Advanced Spaceborne Thermal Emission
       and Reflection Radiometer

AUTHOR
       Yann Chemin, CSU, Australia

SOURCE CODE
       Available at: i.aster.toar source code (history)

       Accessed: unknown

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       © 2003-2022 GRASS Development Team, GRASS GIS 7.8.7 Reference Manual

GRASS 7.8.7                                               i.aster.toar(1grass)

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