26 v. P. GORBATOVA 



in the formulas for calculating the intensity of reflected waves (simple and 



multiple) 



into (10) 



sin (Xq cos ocq 

 multiple) can be replaced by . Formula (3) is then converted 



Co"n (p,p,>i) {Pi+.Pi) (P„-iP„-i) 



■^"^ ^ "^"" 47r(Ao+2^o)^o,p "" (W) 



sincco cos Kg 

 r 



If we apply eqn. (4) to eqn. (3) and go over to a single 

 independent variable sinag, and then proceed to the limit sin (Zq-^O we 

 shall obtain formula (11) for determining the intensity of waves which 

 reflected once above the shot point when reception is vertical: 



2"n'[(P,-P,+i) {Pi+lPi)]o {Pn-lPn-l)v 



_ i=0 .^^, 



Jrei-v— ^^3[ » (11) 



Where [(P^P^-^j) (P^j^^P^]^ is the coefficient of refraction of planar waves 

 when the incidence of the wave is vertical; that is 



mPi^^){Pi^,Pi)]v- ^^'''''' 



QiVi,P+Qi+iVi+i,P 



2^1+1 ^f+i,P 



Qi%p+ Qi+i'Vi+i,p 



(P^_j^P^_j)y is the coefficient of reflection of planar waves when the 

 incidence is vertical on to the reflecting boundary under consideration of 

 the n — 1th and nth layers equal to the following expression 



/ p p >. Qn-lVn-l, p — Qn't^n, p . /-i o\ 



l^«-l^n-lji; = -; TZrZ, » ^^^' 



Qn-l^n-l,p'T- fJn^n,p 



h- is the distance traversed by the wave in the i-th. layer; 



v^^ is the group velocity of longitudinal waves in the i-th layer. 



When we determined the intensities of multiple waves above the shot 

 point, formula (11) is transformed in the same way as formula (3). All the 

 coefficients of reflection and refraction of the multiple wave under consider- 

 ation are introduced into the numerator, each of these coefficients being 



