TROPOSPHERIC PROPAGATION AND RADIO METEOROLOGY 
wal HORIZONTAL POLARIZATION | 100 MC) 
oe | 
mrp VERTICAL POLARIZATION 
Core ee 
<}-+3000 MG 
” 420 
- 
° 
ie] 
o 
So 
> IN DEGREE 
a 
o 
30 40 50 60 70 80 90 
Vv IN DEGREES 
IN DEGREES 
Figure 4. Phase and magnitude 
complete phase change 6 in the form 
V+¢= hip" -++ x (for horizontal polarization) .(3) 
Maximum values of the earth gain factor G occur 
when 6 is an integral multiple of 27; minimum values, 
for odd integral values of +. The corresponding 
values of the angle of elevation B are given by 
te 
(for horizontal polarization.) 
If the reflection coefficient F of the surface is 
assumed to be unity (see Figure 4) the plane earth 
gain factor G, from equation (2), reduces to 
r 
aN 1,3,5,--- 
4h, 
0, 2,4, - -- 
(maxima) 
(minima) 
G = 208(5), 
2 
137 
200 
Fic | a aN 
Ree eae tl 
eNOS Gee 
SEN NESE 
PERN 
Sa 
AC 
AG 
| ial an ED) 
(e/a i al 
3000 MG| 
Ba oe) Se) Ae Eee aa Sa 
0 05 1410 15 20 25 3.0 3.5 40 45 5.0 55 
y IN DEGREES 
EEE Le 
4 Ceisia el 
ik eee 
1 \NGHEE 
(9) 
0 O5 10 15 20 25 30-35 40 45 5.0 55 
y IN DEGREES 
of reflection coefficient for sea water. 
which fluctuates between the limits of 2 and zero. 
The coverage diagram drawn for propagation over 
a perfectly conducting plane on horizontal polariza- 
tion is illustrated in Figure 5. Asan example, consider 
FLAT EARTH 
T 
Fieure 5. Simplified coverage diagram. 
f=200 mc, \=1.5 m, 4: =30.5 m. The values of 6 
for the first three lobe maxima are 0.68°, 1.37°, and 
2.05°, and the maximum ranges are twice the free 
