425
Microwave Vegetation Indices from Satellite Passive Microwave Sensors
values as high as 0.7, which reflects the seasonal vegetation growth. The corresponding MVI shows a significant decrease in the B values to 0.5–0.8, while the A values
increased to around 80–120 K.
The region between 40°N and 60°N latitudes are mainly evergreen needleleaf
forest, croplands, grasslands, and shrublands. These exhibited large changes in both
the optical- and microwave-derived vegetation indices between April and July. The
NDVI values increased from a range of 0.2–0.6 to 0.6–0.9. The B values for the
corresponding areas decreased from 0.6–0.8 to 0.4–0.6, and the A values increased
from a range of 20–100 K to 80–160 K.
(a)
(b)
(c)
(d)
(e)
–0.2
0.2
0.4
0.6
0.8
1
0
0
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1 0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
40
80
120
160
200 0
40
80
120
160
200
FIGURE  18.3  July monthly mean values for (a) NDVI, (b) A(6.925 GHz/10.65 GHz),
(c) A(10.65 GHz/18.7 GHz), (d) B(6.925 GHz/10.65 GHz), and (e) B(10.65 GHz/18.7 GHz).