78 S. D. Shushakov 



Consequently the depth of the fictitious boundary -/„ is given by 



sm}' 

 The hodograph*' for the niuhiple reflection is given by the equation 





1- / . 7-7- o sin^fiv , r^ sin^ n,y „ /qn 



— 1 / 4^1^ -,-- ^ + 4ili X — ^ + x\ (2) 



Vj^ |/ sm'^y sm y 



where n is the number of times the wave is niultipled and x is the distance 

 from the source. 







Fig. 2. Diagram of multiple reflection rays. 



r 



Near the excitation point, when there is a horizontal reflecting boundary^ 

 multiple waves are recorded travelling along a single path normal to this 

 boundary. When the reflecting surface dips, each of these waves is propagated 

 along its own special path (Fig. 3), at the end of which it strikes the zero 

 boundary or boundary I, and after being reflected from this along the same 

 path but in the opposite direction, returns to the detector situated near 

 the point (^' ^^). Odd-number multiples at the end of the path of the incident 

 wave are reflected from the interface I, whereas even-number multiples 

 are reflected from the zero surface. 



Full-path echoes have the following kinematic characteristics. 



* A Russian term referring to distance— time curves. [Editor's footnote]. 



