(1) Laboratoire d 
(2) NASA Ame 
Abstract 
The polarizatioi 
or plant canopi 
features of aer 
investigated, 1( 
possible. We ac 
of such measur 
campaigns of tl 
Mots clef: Poli 
IINTRODUl 
Reflections by | 
radiation is pai 
molecules, are 
scattered at an 
exhibited by th 
the sun. Altho 
rough ground : 
therefore, may 
this problem. 
Many observati 
by Arago, Bab 
polarizing skyl 
atmospheres ar 
lunar surfaces £ 
later on, from 
most impressiv 
were able to d< 
Venus, that the 
Concerning thi 
polarization pn 
Vanderbilt et < 
measurements 
earth-atmosphe 
Deuze et al 1' 
sensors were i 
promizing sens 
not been pursu 
system were pr 
occuring in 1' 
regrettable thai 
polarization st< 
measurements 
and POLDER 
provide the fir: 
We will consi 
interest for rer 
of these target