443 
O -\ 1 1 1 1 1 1 i 1 1 | r—1 I | 
O 10 20 30 40 50 60 70 
TM band 3 
Figure 3. Feature space plot of TM band 4 Figure 6. Greenness plotted against WDVI 
against band 3. 
1 = water 
2 = town 
3 = light soil 
4 = darker soil (mixed) 
5 = vegetation 
6 = dense vegetation 
The resulting image for this WDVI sat is given 
in Fig. 4. 
(5) Calculation of Greenness 
The Greenness for TM data (after offset 
correction) may be calculated by using the 
coefficients given by Crist & Cicone (1984) 
in a global (not site-specific) way. These 
coefficients are provided in Table 3. 
In Fig. 5 the image of the Greenness is 
given. Comparison of Figs. 4 and 5 confirmes 
the statement in section 2.2 that the WDVI 
and the Greenness are much alike. In Fig. 6 
the Greenness is plotted against the WDVI sat 
for the training set. The deviance from a 
straight line is small (r = 0.997). 
5. CONCLUSIONS 
The WDVI can be applied to satellite data, 
yielding results comparable to the Greenness 
of Kauth & Thomas (1976). As a result, for 
many applications not all TM bands are 
needed, but only bands 3 and 4 may yield the 
information needed. This induces a 
considerable simplification of data analysis. 
Subsequently, a straightforward estimation of 
crop characteristics, such as LAI, is 
possible. 
Like the Greenness, the WDVI does not correct 
for atmospheric influence in a multitemporal 
analysis. Some other procedure for 
atmospheric correction has to be applied, 
e.g. darkest pixel method combined with 
spectrally stable (in time) ground features. 
Further research will focus on the latter 
aspect. 
Table 3. Thematic Mapper tasseled cap coefficients. 
Feature 
1 
2 
TM Band 
3 4 
5 
7 
Brightness 
0.3037 
0.2793 
0.4743 
0.5585 
0.5082 
0.1863 
Greenness 
-0.2848 
-0.2435 
-0.5436 
0.7243 
0.0840 
-0.1800 
Wetness 
0.1509 
0.1973 
0.3279 
0.3406 
-0.7112 
-0.4572 
Fourth 
-0.8242 
0.0849 
0.4392 
-0.0580 
0.2012 
-0.2768 
Fifth 
-0.3280 
0.0549 
0.1075 
0.1855 
-0.4357 
0.8085 
Sixth 
0.1084 
-0.9022 
0.4120 
0.0573 
-0.0251 
0.0238