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Amplified signals of channel 2 and 3 are used as command signals 
for the calculator. 
The analogical radiometric signral.is transformed into a numerical 
one (256 levels - 8 bits words). 
For each spectral band the programm uses five measures and 
calculates the average value for two hundred spectra (for example). 
The results corresponding to the relative averace values of 
thousand measures can be seen on a television screen. 
An extra programm is added to the main one in order to calculate 
the ratio of the average value, for each spectral band, to that of 
a standard reflectance spectrum obtained by a white diffuser illumi- 
nated in the same conditions as the studied object. The reflectance 
factor is normalized with respect to the spectral band number 10. 
So we obtain a relative spectral distribution of the reflectance 
factor of an object similar to those obtained with a spectroradiometer 
associated to a graphic recorder. 
Simultaneously, we go on with our measures of the reflectance 
factor of the trees to emphasize and to complete the study of the 
significant parameters which characterize the decay state of the 
observed plants. 
Prospects 
This work can be considered zs a step towards the futur use of 
altitude remote sensing with the spectroradiometer recorder on board 
of an helicopter. Then it would be possible to approach the study 
of the main remote sensing problems : measurement signification, 
reliability of the essential parameters versus the altitude, influence 
on the measurements of the "transparent atmospheric" function and of 
integration to a largest area. 
— Association spectroradiometer - data treatment chain this should 
be performed to improve the study of Rouen forests (and agriculture 
eventually) (French-German project which has been presented to the 
European Community - Bruxelles). 
- Data treatment obtained for different altitudes by Scanner 
(Daedalus for instance) - including Landsat II data - from our 
conclusions about the real determination possibilities of any signifi- 
cant parameters of the forest decays by remote sensing spectroradio- 
metry.