i.albedo.1grass - Man Page
Computes broad band albedo from surface reflectance.
Keywords
imagery, albedo, reflectance, satellite, Landsat, ASTER, AVHRR, MODIS
Synopsis
i.albedo
i.albedo --help
i.albedo [-mnl8acd] input=name[,name,...] output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags
- -m
MODIS (7 input bands:1,2,3,4,5,6,7)
- -n
NOAA AVHRR (2 input bands:1,2)
- -l
Landsat 5+7 (6 input bands:1,2,3,4,5,7)
- -8
Landsat 8 (7 input bands:1,2,3,4,5,6,7)
- -a
ASTER (6 input bands:1,3,5,6,8,9)
- -c
Aggressive mode (Landsat)
Albedo dry run to calculate some water to beach/sand/desert stretching, a kind of simple atmospheric correction- -d
Soft mode (MODIS)
Albedo dry run to calculate some water to beach/sand/desert stretching, a kind of simple atmospheric correction- --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,...]Â [required]
Name of input raster map
- output=name [required]
Name for output raster map
Description
i.albedo calculates the albedo, that is the Shortwave surface reflectance in the range of 0.3-3 micro-meters. It takes as input individual bands of surface reflectance originating from MODIS, AVHRR, Landsat or Aster satellite sensors and calculates the albedo for those. This is a precursor to r.sun and any energy-balance processing.
Notes
It uses for Landsat 8 the weighted average reflectance (temporary solution until an algorithm is found).
It assumes MODIS product surface reflectance in [0;10000].
Example
The following example creates the raster map "albedo_lsat7_1987" from the LANDSAT-TM5 bands in the North Carolina dataset:
g.region raster=lsat5_1987_10 -p i.albedo -l input=lsat5_1987_10,lsat5_1987_20,lsat5_1987_30,lsat5_1987_40,lsat5_1987_50,lsat5_1987_70 output=albedo_lsat7_1987
Figure: Resulting albedo map from LANDSAT 5
The following example creates the raster map "albedo_lsat7_2000" from the LANDSAT-TM7 bands in the North Carolina dataset:
g.region raster=lsat7_2000_10 -p i.albedo -l input=lsat7_2000_10,lsat7_2000_20,lsat7_2000_30,lsat7_2000_40,lsat7_2000_50,lsat7_2000_70 output=albedo_lsat7_2000
Figure: Resulting albedo map from LANDSAT 7
Todo
Maybe change input requirement of MODIS to [0.0-1.0]?
References
For a 2 band determination of the Aster BB Albedo see the following:
Salleh and Chan, 2014. Land Surface Albedo Determination: Remote Sensing and Statistical Validation. in proceedings of FIG 2014 (PDF)
See Also
r.sun, i.vi
Author
Yann Chemin
Source Code
Available at: i.albedo source code (history)
Accessed: Saturday Nov 09 07:56:08 2024
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