GRASS GIS manual: i.fusion.brovey

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=name ms2=name ms3=name pan=name output_prefix=string [--verbose] [--quiet]

Flags:

-l: LANDSAT sensor
-q: QuickBird sensor
-s: SPOT sensor
--verbose: Verbose module output
--quiet: Quiet module output

Parameters:

ms1=name [required]: Name of input raster map (green: tm2 | qbird_green | spot1)
ms2=name [required]: Name of input raster map (NIR: tm4 | qbird_nir | spot2
ms3=name [required]: Name of input raster map (MIR; tm5 | qbird_red | spot3
pan=name [required]: Name of input raster map (etmpan | qbird_pan | spotpan)
output_prefix=string [required]: Prefix for output raster maps

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 Brovey fusion at 14.25m

Colors may be optionally optimized.

REFERENCES

Original Brovey formula reference unknown, probably
Roller, N.E.G. and Cox, S., 1980. Comparison of Landsat MSS and merged MSS/RBV data for analysis of natural vegetation. Proc. of the 14th International Symposium on Remote Sensing of Environment, San Jose, Costa Rica, 23-30 April, pp. 1001-1007
Pohl, C., and J.L. van Genderen, 1998. Multisensor image fusion in remote sensing: concepts, methods and application. Int. J. of Rem. Sens., 19, 823-854.
M. Neteler, D. Grasso, I. Michelazzi, L. Miori, S. Merler, and C. Furlanello, 2005. An integrated toolbox for image registration, fusion and classification. International Journal of Geoinformatics, 1(1):51-61 (PDF)

AUTHOR

Markus Neteler, ITC-irst, Italy

Last changed: $Date: 2011-11-08 13:24:20 -0800 (Tue, 08 Nov 2011) $

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