\\<;UO-OK-\I{I<I\ \l, MEAST KKiHKNTS 



73 



140 



20 40 60 80 100 120 



Figure 17. Signal strength as function of range. X band, Antigua experiments. 



160 



distances from the transmitter the second mode 

 prevails, but at greater distances it will become 

 smaller than that of the first which decreases less 

 rapidly with distance. 



Finally Figure 18 shows a set of curves for attenua- 

 tion versus distance of the target for an X-band radar 

 on Antigua. Again it is evident that, on the whole, 

 the lowest elevation of the radar gives the largest 

 signal strength. 



86 ANGLE -OF- ARRIVAL MEASUREMENTS 



Because the effects of nonstandard propagation 

 are most pronounced at great distances from the 



20 ' 



5 50 



RADAR ECHO STRENGTH VS RANGE 



-APS-I5A RADAR- 



II APRIL 1945 



20 25 30 35 



RANGE NAUTICAL MILES 



Figure 18. Radar echo strength as function of range. 

 X band, Antigua experiments. Target is a PC boat. 



