144 



REFLECTION COEFFICIENTS 



Figure 15. Cross section of Forth Gain Bay (Wales) in vertical plane through transmitter and receiver. 



It is seen that in the previous experiments^'- no 

 attempt was made at finding the phase angle shift at 

 reflection. At 10 cm^ such an attempt was made. How- 

 ever, the distances involved here could not be meas- 

 ured more accurately than a small fraction of a half 

 wavelength, or 5 cm. Therefore, these experiments 

 are not to be considered, as the author himself points 

 out, as giving quantitative information on the phase 

 angle shift at reflection and they will not be dis- 

 cussed here. 



1.0 



as 



0.8 



0.7 



0.6 



p 0.5 



0.4 



V** 



•rX. 



'•' \* • . 

 . — ^ — _■ 



, — -.i — ^,^ — . 



OJ 



0.2 



0.1 



\ 2 3 4 5 6 



GRAZING ANGLE IN DEGREES 



Figure 16. Sea reflection coefficient p, versus grazing 

 angle ^ at 10 cm. Vertical polarization. 



'^" Summary of Experimental 



Investigations on Reflection 



Here the results of certain additional reports of 

 experiments on microwave reflection by either sea or 

 land performed under more nearly operational con- 

 ditions are summarized.^"' 



In one series of experiments* performed by British 

 workers, at 9.3 cm, the transmitter was located on the 

 shore and could be ^jlaeed at two heights, 35 and 130 



t.o 



0.9 



0.8 



0.7 



0.6 



fi 



0.5 



0.4 



0.3 



0.2 



0.1 



2 3 4 



GRAZING ANGLE IN DEGREES 



5 6 



OVER SEA 



Figure 17. Sea reflection coefficient Pn versus grazing 

 angle 4/ at 10 cm. Horizontal polarization. 



