table of contents
i.aster.toar(1grass) | GRASS GIS User's Manual | i.aster.toar(1grass) |
NAME¶
i.aster.toar - Calculates Top of Atmosphere Radiance/Reflectance/Brightness Temperature from ASTER DN.
KEYWORDS¶
imagery, radiometric conversion, radiance, reflectance, brightness temperature, satellite, ASTER
SYNOPSIS¶
i.aster.toar
i.aster.toar --help
i.aster.toar [-rabcde]
input=name[,name,...] dayofyear=float
sun_elevation=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 brightness 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
NOTES¶
Internally, a gain code is defined to modify gains according to
spectral 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: Saturday Jul 27 17:08:59 2024
Main index | Imagery index | Topics index | Keywords index | Graphical index | Full index
© 2003-2024 GRASS Development Team, GRASS GIS 8.4.0 Reference Manual
GRASS 8.4.0 |