rization (wavelength). The decision function R here can he 
determined in the general case as 
R-R(A%(P,),a%(Pj) ■■■aT(p„)) , (4) 
where P^, ... P^ are polarizations 
A Zi? = z\ 7) + & ( ¿a T#) 
Until recently, practical use has mainly been made of 
the measurements on two orthogonal and circular polariza 
tions. For most plants on the horizontal polarization ab 
sorption is much less than on any other and, thus, this 
polarization is optimum when applied to the solution of the 
problem of detection of the boundary ”land-water” under the 
vegetation layer. Shown in Fig. 1 is the fragment of the 
registergram with synchronous recording of the radio-ther 
mal signal showing that the boundary ”land-water” is cha 
racterized by a sharp decrease in the radio-brightness 
temperature. Thus, in the case of microwave radiometrical 
sensing the refining of the boundary poses no difficulty. 
The problem of discrimination of boggy sections of 
the terrain is similar to the problem considered above, 
but it is distinguished with a number of specific features 
in selection of the criterion against the value of which 
the decision is taken on the presence or absence of boggy 
areas. The registergram of the radio-thermal signal cor 
responding to the route passed through the boggy terrain