iown with a sufficient 
annels instead of using 
ipe is the same for each 
tion because they don't 
hannels 4 and 5 is: R45 
inces measured by the 
ng the snow reflectance 
sition as at the time of 
ween 0° and 315° and 
measured mean convex 
nd reflectance without 
in an operationnal way. 
s done for other ratios: 
grain size and does not 
tionnal reflectances and 
IX) 
- 0.6 
1-0.4 
700 800 900 1000 
nicrometers) 
e in the Alps. The main 
;ensing data acquisition, 
ime, 2 spacebome. This 
study the usefulness of 
satellite data to retrieve helpful information on the snow mantle (temperature, snow type) and to validate 
snow metamorphism models, to intercalibrate different sensors. Preliminary results on temperature and snow 
grain size from the 24 April 1992 experiment are very satisfactory. We will complete this work and do the 
same kind of studies for the other experiments. 
ACKNOWLEDGEMENTS 
The ARAT aircraft were operated by the Institut Géographique National, the push-broom by A. Pasquet 
from CNES and J. Duffaut from DERO, the ISM spectrometer by D. Alcayde, G. Marty from the Centre 
Spatial d'Etude du Rayonnement and J.P. Bibring, B. Gondet from the Institut d'Astrophysique Spatiale. 
Those experiments were funded by the French Programme National de Teledetection Spatiale and the 
Centre National d'Etude Spatiale. 
We are grateful to the numerous colleagues who participated to the field work. 
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