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NAME
i.aster.toar - Calculates Top of Atmosphere Radiance/Reflectance/Brightness Temperature from ASTER DN.
KEYWORDS
imagery, Terra-ASTER, DN, radiance, reflectance, brightness temperature
SYNOPSIS
i.aster.toar
i.aster.toar help
i.aster.toar [-rabcde] input=name[,name,...] dayofyear=float sun_elevation=float output=name [--overwrite] [--verbose] [--quiet]
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
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- input=name[,name,...]
- Names of ASTER DN layers (15 layers)
- dayofyear=float
- Day of Year of satellite overpass [0-366]
- sun_elevation=float
- Sun elevation angle (degrees, < 90.0)
- output=name
- 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 after importing your Aster imagery from storage format 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 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)*/
TODO
SEE ALSO
i.landsat.toar
r.in.aster
AUTHORS
Yann Chemin, CSU, Australia
Last changed: $Date: 2010-04-03 19:49:00 +1100 (Sat, 03 Apr 2010) $
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