chapter 9 band algebra and vegetation indices band transformations a. dermanis
TRANSCRIPT
CHAPTER 9CHAPTER 9
Band AlgebraBand Algebraand Vegetation Indicesand Vegetation Indices
BAND TRANSFORMATIONSBAND TRANSFORMATIONS
A. Dermanis
Algebraic operation
Addition:bi
aii xxx
pixel i, bands a, b Band algebra
A. Dermanis
Algebraic operation
Addition:bi
aii xxx
Subtraction:bi
aii xxx
pixel i, bands a, b Band algebra
A. Dermanis
Algebraic operation
Addition:bi
aii xxx
Subtraction:bi
aii xxx
Absolute difference: bi
aii xxx
pixel i, bands a, b Band algebra
A. Dermanis
Algebraic operation
Addition:bi
aii xxx
Subtraction:bi
aii xxx
Absolute difference: bi
aii xxx
Multiplication: bi
aii xxx
pixel i, bands a, b Band algebra
A. Dermanis
Algebraic operation
Addition:bi
aii xxx
Subtraction:bi
aii xxx
Absolute difference: bi
aii xxx
Multiplication: bi
aii xxx
Division:bi
ai
ix
xx
pixel i, bands a, b Band algebra
A. Dermanis
Algebraic operation
Addition:bi
aii xxx 5102 ix
Subtraction:bi
aii xxx 254254 ix
Resulting values
Absolute difference: bi
aii xxx 2540 ix
Multiplication: bi
aii xxx 21 255ix£ £
Division:bi
ai
ix
xx 255
255
1 ix
pixel i, bands a, b Band algebra
A. Dermanis
127 1 ( )
127 ( )2
a bi i i
i a bii i
x x xx x
x x
ì + <ï
=¢ í+ ³ïî
Algebraic operation
Addition:bi
aii xxx 5102 ix
Reduction
2i
i
xx
Subtraction:bi
aii xxx 254254 ix
2
255 i
i
xx
Resulting values
Absolute difference: bi
aii xxx 2540 ix
01
0
i
iii x
xxx
Multiplication: bi
aii xxx 21 255ix£ £ b
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Division:bi
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xx 255
255
1 ix
pixel i, bands a, b Band algebra
A. Dermanis
Vegetation indices k mi i
i k mi i
x xx
x x
-=
+(pixel i, bands k and m)
A. Dermanis
Vegetation indices
56
566 MSSMSS
MSSMSSNDVI
57
577 MSSMSS
MSSMSSNDVI
LandsatMutispectral Scanner
k mi i
i k mi i
x xx
x x
-=
+(pixel i, bands k and m)
vegetation
A. Dermanis
Vegetation indices
56
566 MSSMSS
MSSMSSNDVI
57
577 MSSMSS
MSSMSSNDVI
34
34TM TMTM
TMTMNDVI
Thematic Mapper (ETM+)
LandsatMutispectral Scanner
k mi i
i k mi i
x xx
x x
-=
+(pixel i, bands k and m)
vegetation
A. Dermanis
Vegetation indices
56
566 MSSMSS
MSSMSSNDVI
57
577 MSSMSS
MSSMSSNDVI
34
34TM TMTM
TMTMNDVI
23
23HRV HRVHRV
HRVHRVNDVI
Thematic Mapper (ETM+) SPOT HRV (SPOT 4 HRVIR)
LandsatMutispectral Scanner
k mi i
i k mi i
x xx
x x
-=
+(pixel i, bands k and m)
vegetation
A. Dermanis
Vegetation indices
56
566 MSSMSS
MSSMSSNDVI
57
577 MSSMSS
MSSMSSNDVI
34
34TM TMTM
TMTMNDVI
23
23HRV HRVHRV
HRVHRVNDVI
0.5NDVITVI 66
0.5NDVITVI 77 |0.5NDVI||5.0NDVI|
5.0NDVITVI 6
6
66
Thematic Mapper (ETM+) SPOT HRV (SPOT 4 HRVIR)
LandsatMutispectral Scanner
Transformed Vegetation Indices
k mi i
i k mi i
x xx
x x
-=
+(pixel i, bands k and m)
vegetation
A. Dermanis
Original Band TM3 Original Band TM4
Normalized difference vegetation index NDVI = (TM4-TM3) / ( TM4+TM3)
Example of Vegetation index:
The city and nearby airport become dark, while white areas correspond to green vegetation
A. Dermanis
Band TM3 Band TM4
NDVI = (TM4-TM3) / ( TM4+TM3)
Two original TM bands and the derived normalized difference vegetation index (NDVI) for a mountainous area.
The mountain peak which is covered with snow appears dark, while the forest area appears close to white.
Note the disappearance of the “shadow” effects caused in the original bands by varying terrain orientation
A. Dermanis