276 



ATTENUATION OF RADIO WAVES 



Table 7.3. Water vapor attenuation (one way) in dB/km 



[After Gumi-Eastl. 



P, pressure in atmospheres; W, water vapor content in g/m"^ 



*The pressure dependencies shown are only approximate. Near the 1. 35 cm water vapor absorption line 

 (between 1. cm and 2. cm) no simple power dependency of P and W is accurate. 



Table 7.4. Pressure and temperature correction for oxygen attenuation for wavelengths 



between 0.7 and 10 cm 

 [After Qunn-East] 



o 



O I0-' r 



CVJ 



< 



I 10-2 



CD 



8 10-3 

 < 



Z 



UJ 



^-4 



0.8 



.5 2 



6 8 10 



A (cm) 



Figure 7.2. Attenuation of microwaves by atmospheric gases. 

 (After Guim and East, 1954). 



