SPATIAL PROBLEMS IN GEOMETRICAL SEISMICS 



6a 



The point from which the azimuths are read off coincides Avith the direction 

 of incidence of the inchned refracting boundary. Line 5 is a trace projection 

 <»f the intersection of the radial surface with the inchned refracting plane. 



^•^gxT^ 



-- 2 — 

 3 



4 — H 



Fig. 10. Determination of points of emergence of rays onto observation plane (30° 

 ray surface), a — plan; h — cross section in vertical plane containing azimuths and 

 180° (the generators of the 30° ray surface are shown). 1 — structure contours ol 

 refracting interface; 2 — structure contours of reflecting interface; 3-4-5-6 — trace 

 projections of intersection of 30° ray surface with refracting boundary (3), reflecting 

 boundary (4), refracting boundary after reflection (5), and observation plane (6); 

 7 — lines of equal, azimuths; 8 — points of emergence of rays; 9 — projections of separate 



rays. 



