Geology Reference
In-Depth Information
(a)
(b)
0.20
0.10
OW
0.15
0.05
OW
A
0.10
0.00
C
C
0.05
-0.05
B
A/B
0.00
0.00
-0.10
0.05
0.10
0.15
PR
R
(19)
0.20
0.25
0.30
0.00
0.05
0.10
0.15
PR(19)
0.20
0.25
0.30
(c)
(d)
0.2
0.20
0.15
OW
0.1
OW
0.10
0.0
A
0.05
Ice
C
B
A/B
-0.1
0.00
0.00
0.05
0.10
0.15
0.20
-0.10
0.00
0.10
0.20
0.30
0.40
GR
85
H
19
H
PR
R
(85)
Figure 10.11
Scatterplots of SSM/I‐derived polarization and gradient ratios from observations over the Weddell
Sea, acquired on 15 September 1992. Gray circles in (a) are tie points of OW and ice types A, B, and C (see defi-
nitions in the text). Definition of angle
ϕ
is also shown in (a). The gray circles in (c) and (d) are modeled ratios for
the three pure surface types (A/B, C, and OW) with different atmospheric conditions. Increasing weather means
more clouds. [
Markus and Cavalieri
, 2000, Figure 1, with permission from IEEE].
assumed. For each surface, the 12 different atmospheric
conditions are used to generate a total of 48 sets of
brightness temperatures (each set has 7 spectral points
corresponding to the SSM/I spectral channels). These are
the reference values (tie points) from those surfaces under
the distinct atmospheric conditions.
2. Those typical values are then used to calculate a
set expected
T
b
using equation (10.15) for different
combinations of concentrations of the three ice types:
FY ice, thin ice, and OW; or FY ice, C‐type ice plus the
OW. The three ice types are combined in different con-
centration ratios from 0% to 100% in a step of 10%.
3. From the above values of
T
b
the three parameters
PR
R
(19), PR
R
(85), and ΔGR are calculated. These param-
eters are then expressed in the vector form
R
mod
= [PR
R
(19),
PR
R
(85), ΔGR]
mod
.
