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NAME

i.fusion.brovey - Brovey transform to merge multispectral and high-res panchromatic channels

KEYWORDS

imagery, fusion, Brovey

SYNOPSIS

i.fusion.brovey
i.fusion.brovey help
i.fusion.brovey [-lqs] ms1=string ms2=string ms3=string pan=string outputprefix=string [--overwrite] [--verbose] [--quiet]

Flags:

-l
LANDSAT sensor
-q
QuickBird sensor
-s
SPOT sensor
--overwrite
Allow output files to overwrite existing files
--verbose
Verbose module output
--quiet
Quiet module output

Parameters:

ms1=string
Name of input raster map (green: tm2 | qbird_green | spot1)
ms2=string
Name of input raster map (NIR: tm4 | qbird_nir | spot2)
ms3=string
Name of input raster map (MIR; tm5 | qbird_red | spot3)
pan=string
Name of input raster map (etmpan | qbird_pan | spotpan)
outputprefix=string
Name for output raster map prefix (e.g. 'brov')

DESCRIPTION

i.fusion.brovey performs a Brovey transformation using three multispectral and the panchromatic satellite image scene channels. Three new channels are calculated according to the formula:
                            DN_b1 
    DN_fused = ------------------------------- * DN_pan
                    DN_b1 + DN_b2 + DN_b3
The assignment of the channels depends on the satellite. The module's help text (above) suggests for LANDSAT-7, QuickBird and SPOT.

NOTES

The command changes temporarily to the high resolution of the panchromatic channels for creating the three output channels, then restores the previous region settings. The current region coordinates are respected. The three pan-sharpened output channels may be combined with d.rgb or r.composite.

EXAMPLE

Calculation of Brovey fusion map from North Carolina Landsat scene:
g.region rast=lsat7_2002_20 -p

# R, G, B composite at 28.5m 
d.rgb b=lsat7_2002_10 g=lsat7_2002_20 r=lsat7_2002_30

# Brovey fusion
i.fusion.brovey -l ms1=lsat7_2002_20 ms2=lsat7_2002_40 \
                   ms3=lsat7_2002_50 pan=lsat7_2002_80 \
                   outputprefix=brovey

# display at 14.25m
g.region rast=brovey.blue -p
d.rgb b=brovey.blue g=brovey.green r=brovey.red
Results:

 R, G, B composite of Landsat at 28.5m
R, G, B composite of Landsat at 28.5m
 R, G, B composite of Landsat Brovey fusion at 14.25m
R, G, B composite of Landsat Brovey fusion at 14.25m

Colors may be optionally optimized.

SEE ALSO

i.his.rgb, i.rgb.his, d.rgb, r.composite

REFERENCES

AUTHOR

Markus Neteler, ITC-irst, Italy

Last changed: $Date: 2010-02-12 08:01:24 -0800 (Fri, 12 Feb 2010) $


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