ULTRA-SIIORT-WA VE TRANSMISSION PHENOMENA 



111 



stantially halfway between the antenna sites, and very great altitude 

 changes become necessary to exhibit a maximum-to-minimum cycle. 

 This reflection component cannot thus be demonstrated from two hill 

 locations such as we had; but one of the hills together with a receiver 

 carried by an airplane will suffice. We were able thus to demonstrate 

 all the three main reflections. 



LJ 40 



80 





40 



80 120 160 200 24Q 



FEET 



Fig. 9 — Profile map of McCatharn's Hill. 



Fig. 9 gives a profile of the McCatharn Hill along the radio trans- 

 mission line and Figs. 10 and 11 show the received field strength 



20 30 40 



ANTENNA HEIGHT IN FEET 



60 



Fig. 10— Local reflection at McCatharn Hill. Vertical 

 polarization x = 4.08 meters. 



variation as the antenna was raised and lowered " for both horizontally 

 and vertically polarized radiations. Assuming this hill to be a medium 



' The receiving set. in the truck, was located on the hilltop after making sure 

 that stationary diffraction fringes were of negligible amplitude. By permission ot 



