ULTRA-SHORT WAVE PROPAGATION 161 



and 



Eq is the field with straight edge removed, a and h are Fresnel integrals, 

 H is the height of the obstruction above the straight line from trans- 

 mitter to receiver, rx and r2 are the distances from the obstruction to 

 the transmitter and receiver respectively (.Fig. 18). 



To facilitate calculation the value of C has been plotted in Fig. 19. 

 7} may be expressed as follows, 



r? = m + 7r^V2, 

 where }{v) is the function plotted in Fig. 20. 



