Page 62 - Integrated Wireless Propagation Models

40 C h a p t e r 0 n e

Obstruction 1 Obstruction 2
(a) Two knife edges
02

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/ {":��;2J 03
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/ _,. "' / h s'\
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T ' \
- - , \
, ,
:- - - �
I
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- - 1
(b) Three knife edges
FIGURE 1.9.2.2.2.2 Epstein-Peterson method.

where a is a spacing parameter expressed as

(1.9.2.2.2.2)

Japanese Method
The Japanese method45 follows the same procedure as the Epstein-Peterson method,
calculating losses caused by each knife edge first and then summing all to obtain the
overall path loss. But it uses different parameters of distance and effective height.
1
Figure . 9.2.2.2.3 shows the effective transmitter heights T, T', and T", each of which is
found by projecting a ray from the top of the knife edge, passing on the top of the left
neighboring knife edge, and ending at the different height at the location of the trans­
mitter. The path loss for each knife edge is given by
LOI = f(d1, d2 , h 1)
=
Loz f(dl + d 2 A , h z )
+
Lo3 = f(dl + d z d 3 , d4, h 3)