REFLECTION AND TRANSMISSION OF RADIO WAVES 



PERCENTAGE OF TIME THE VALUES EXCEED THE ORDINATE 



Fig. 4-18 Amplitude Distribution of F-51 Echo, Showing Effect of Propeller 



Reflection. 



The data in Figs. 4-20 to 4-22 also give the frequency dependencies of the 

 radar area. A single number for the average radar area was obtained for 

 each frequency by averaging all the values of a (in square meters) plotted 

 in each figure. These averages are controlled by the large peak in the 

 neighborhood of the broadside aspect. Similar numbers were obtained for 

 all aspects measured outside of the broadside region. These latter numbers 

 give a measure of the frequency dependencies of the aircraft for most 

 tactical applications. The results are shown in Table 4-1. The B-36 and 

 B-45 averages are roughly independent of frequency, but the F-51 average 

 a increases approximately proportional to frequency. 



-E 4-1 



COMPARISON OF B-36, B-45, AND F-Sl 

 AVERAGE RADAR AREAS 



'Broiulside ret^ion saturated. 



