80
Tab. 1
Spectral resolutions of the SPOT - and Thematic Mapper scanner
and of the Landsat 5 / Thematic Mapper
SPOT - Simulation
pm
TM Simulation
pm
Landsat 5/TM
pm
SS 1 0,50 - 0,59
TMS 1 0,44 - 0,49
TM 1 0,45-0,52
SS 2 0,61 - 0,68
TMS 2 0,54-0,58
TM 2 0,52 - 0,60
SS 3 0,79 - 0,89
TMS 3 0,62-0,66
TM 3 0,63 - 0,69
TMS 4 0,76-0,86
TM 4 0,76 - 0,90
TMS 5 1,535-1,705
TM 5 1,55-1,75
TMS 6 8,00-13,00
TM 6 10,4-12,5
TMS 7 2,105 - 2,368
TM 7 2,08-2,35
Tab. 2 Correlation coefficients of forest test areas
SPOT - Simulation
SS 1
SS 2
SS 2
0,91
SS 3
-0,13
-0,02
TM - Simulation
TMS 2
TMS 3
TMS 4
TMS 5
TMS 6
TMS 7
TMS 1
0,93
0,85
_ 0,27
0,64
0,71
0,72
TMS 2
—
0,94
0,23
0,65
0,76
0,84
TMS 3
—
1
o
o
NJ
0,49
0,71
0,88
TMS 4
—
0,67
0,31
-0,0002
TMS 5
—
0,82
0,50
TMS 6
—
0,69
Landsat 5/TM
Mixed forest testsite
TM 2
TM 3
TM 4
TM 5
TM 7
TM 1
0,80
0,82
0,46
0,66
0,72
TM 2
—
0,89
0,64
0,75
0,79
TM 3
—
0,42
0,67
0,80
TM 4
—
0,31
0,65
TM 5
—
0,94
Landsat 5./ TM
Deciduous forest
testsite
TM 2
TM 3
TM 4
TM 5
TM 7
TM 1
0,87
0,89
CM
O
1
0,44
0,72
TM 2
—
0,94
-0,22
0,51
0,79
TM 3
—
cn
o
1
0,50
0,80
TM 4
—
0,42
0,01
TM 5
—
0,82
4 RESULTS
4.1 Selection of bands
An analysis of the correlation coefficients from the
SPOT-simulation showed very high values between the
bands in the visible spectral range, suggesting a
very similar information content. The possibility of
a good differentiation between the forest classes was
offered by the selection of bands SS1 (green) and SS3
(near infrared), further analysis showed that the
band SS2 (red) had limited value for the research in
question.
As in previous research a high correlation was estab
lished between the visible wavelength of the TM-si-
mulation bands. However in comparison a lower corre
lation was to be found between the visible and the
near infrared wavelengths. In the scene presented
here, there is a high correlation between bands IMS4
(near infrared) and TMS5 (middle infrared) for forest
classes but not for agricultural areas (Tab. 2).
Therefore the TM-simulation bands TMS2 (green), TMS3
(red), TMS4 (near infrared) and TMS5 (middle infra
red 1500 nm) were selected for further interpretation.
Owing to atmospherical influences band TMS1 (blue)
was not chosen, band TMS7 (middle infrared 2300 nm)
because of its limited dynamic range and its high
correlation with band TMS5 was also not used.
The correlation values of two forest areas in the
Landsat 5/TM scene from the 7.7.84 are presented in
table 2. On the whole they confirm the results of the
simulation. There exists a high correlation of the
bands TM4 and TM5 for mountainous mixed forest areas
similar: to that for the mixed deciduos forest of the
TM-sirnulation. In comparison there is a low correla
tion between bands TM4 and TM5 for the lowland-forest
areas of the Rhine valley in Landsat/TM scene from
July 1984, which could be a result of different
moisture content in the forest areas, for example in
poplar stands.
Corresponding to the results of the simulation, the
bands TM2, 3, 4 and 5 were chosen, the bands TM1 and
7 were also left out here for reasons already ex
plained .
4.2 Signati
The differ«
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