364 
5. CONCLUSIONS 
Reasonable correlations were found between the first derivative of canopy spectral reflectance at 1142nm 
and wet%. However, the strength of this relationship and the wavelength position of the maximum was 
found to be sensitive to the degree of spectral smoothing. This sensitivity is attributed to the different levels 
of smoothing emphasising different spectral features across a spectral region where the two variables are 
generally highly correlated. The effect emphasises in particular that the exact position of peak correlation 
between the two variables should be interpreted with caution especially across spectral regions where the 
correlation is generally high. A simple index of the relative depth of the water absorption feature around 
1150nm was found to have a as high a correlation and to be less sensitive to data smoothing. 
ACKNOWLEDGEMENTS 
The authors gratefully acknowledge ESA/JRC for funding the UK EISAC’89 Campaign and BNSC-RSADU 
for their role in organising the ground data collection at the Tadham Moor site during May 1989. This 
exercise involved many UK research groups and the authors gratefully acknowledge the time, effort and 
support of all those involved. 
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