508
1000
~
"0
><(0 800
c
'"
;g 600
Q;
8
c
~ 400
~
~ 200
4
2
°0~~~--~1~0---i--~2~0---i--~3~0--~--~4~O
Frequency, GHz
Wet Snow Experimental Data
1 GHz
2
5
10
18
37
10
12
14
Volumetric Water Content, %
M. Hallikainen
Figure 18.14: Absorption coefficient (top) and penetration depth (bottom) for snow, calculated
using the modified Debye-like model, as a function of frequency and volumetric liquid water
content (Hallikainen and Winebrenner, 1992).
18.5 The Physical Nasis for Remote Sensing of Sea Ice
and Snow
18.5.1 Effect of atmosphere
The microwave emission received by a spaceborne radiometer consists of contributions from the
Earth, atmosphere and space:
where
e
Ts
T
surface emissivity
physical temperature of the radiating portion of the surface
atmospheric opacity
(18.26)