FACTORS INFLUENCING TRANSMISSION 373 
Figure 12. Amplitude of the reflection coefficient p 
versus angle of reflection © for sea water. (From 
Radiation Laboratory Report C-11.) 
where ¢ is temperature in degrees centigrade. 
The conductivity of fresh water is much smaller. 
An average for inland lakes is ¢ = 107? mho per 
meter. For wavelengths shorter‘than about 10 cm, 
the dielectric constant is influenced by the fact that 
water is built up of polar molecules. The maximum 
effect is found for wavelengths of the order of 1 em. 
For this region, there is no appreciable difference 
between salt and fresh water. 
The probable run of e; for sea water is shown in 
Ficure 13. Phase of the reflection coefficient @ versus 
angle of reflection Y for sea water. Reflected wave H, 
lags incident wave E; by @. (From Radiation Labora- 
tory Report C-11.) 
(EES a PG a 
tT Ticarzon TAL POLARIZATION 200M |_| 
GS Sl Se Re ees, 
i Ee De 
ANG 
(BERS E2BEo 
| aa Ths [ee 
ele eal ee 
° 3° ° (OS fa ELT EP eck Cen CLP n Lee 
Ficure 14. Amplitude p of the reflection coefficient 
versus reflection angle Y from YW = 0 to W = 5.5° for 
sea water. 
Figure 11. The part of the e; curve extending from 
6,000 me to 30,000 me corresponds essentially to 
results obtained at Clarendon Laboratory, Oxford. 
Other investigators give results which are markedly 
different. This curve is thus affected by consider- 
able uncertainties and should be used with caution. 
In Figures 12 to 15 are shown amplitude and 
phase of the reflection coefficient for a smooth sea for 
various frequencies. Figure 12 gives the amplitude 
p of the reflection coefficient for both kinds of 
polarization, for reflection angles up to yO degrees, 
and for 100 and 3,000 mc. Figure 13 gives the 
phase @ under the same conditions. The next two 
VERTICAL POLARIZATION = 
Se 
Uy 
Ail 
|| 
y 
A 
r 
Y 
Es 
fi 
HH 
y————— 
Figure 15. Phase @ of the reflection coefficient versus 
reflection angle V from YW = 0 toW = 5.5° for sea water. 
E; lags E; by @. (From Radiation Laboratory Report 
C-11.) 
