OPTICAL I'KOI'KKTIIvS OF TIIK KVRTII S SURFACE \!\l) \ TMOSI'll KKK 



:« 



140 



120 



100 



I- 

 z 

 < 

 I- 



0) 



z 

 o 

 o 



o 



(X 

 H 



o 



Ul 



_l 



UJ 



o 



24. 26 28 30 



Figure 2. Dielectric constant of sea water at 17 C. 



ductivity in mhos per meter, and X the wavelength 

 in meters. In general, and especially in the micro- 

 wave region, e r and e,- are themselves functions of 

 the frequency. Figure 2 shows the variation of the 

 real and imaginary parts of the complex dielectric 

 constant of sea water at 17 C for ultra-high fre- 

 quencies according to the best available experi- 

 mental data. 



The reflection coefficient is given by Fresnel's 

 formulas. Let \p indicate the angle between the 

 incident ray and the horizontal reflecting surface. 

 Then, for horizontal polarization 



R = pe -i0 = 



sin 



\p — \/«c — COS 2 \p 



sin \f/ + v e c — cos 2 4> 

 and for vertical polarization 



R = pe->0 = 



e, sin 



<A - \A 



cos 2 \p 



tr sin 



\p + y/i c — cos 2 i/- 



(7) 



(8) 



.5° 

 + 



Figure 3. Amplitude, p, of the reflection coefficient 

 versus reflection angle, i/', from \f/ = to \p = 5.5° for 

 sea water. 



where p designates the magnitude of the reflection 



coefficient, and 4> the phase lag of the reflected ray 



at reflection. Figure 3 illustrates the amplitude of the the angle \f/ for several frequencies. Figure 4 shows 



reflection coefficient for sea water as a function of the corresponding phase lag at reflection. 



