NAME

       i.albedo  - 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,...] [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]?

SEE ALSO

        r.sun, i.vi

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)

AUTHOR

       Yann Chemin

SOURCE CODE

       Available at: i.albedo source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual