JRC JUE-95SA - Page 58

4-6
II. Estimation procedure with the chart ( for un-cylindrical obstacles)
i) Estimate the distance (R) from the antenna to the obstacle R (m)
ii) Read the effective propagation radius (r) at R meter distance
(at point A) from the antenna in the Chart II-1 r (m)
iii) Estimate the obstacle area (S
B
) just occupying effective propagation
radius (see hatched area shown in Example 2.) S
B
(dm
2
)
iv) Read the loss in the Chart II-2 L
B
(dB)
v) Determine whether the loss is allowable.
Chart4.4.4c Effective Propagation Radius vs. Obstacle’s Distance
S
B
=0.5m
r=1m
Effective
Propagation
radius
R=5m
Radar mast
Example
i) R:5m
ii) r:1m
iii) S
B
:0.5m
2
iv) L
B
:1dB (approx.)
v) Allowable
Fig.4.4c EME Installation against un-cylindrical obstacles