The response of two points

Another simple geometry is a reflecting point within the earth. A wave incident on the point from any direction reflects waves in all directions. This geometry is particularly important because any model is a superposition of such point scatterers. Figure 8 shows an example.

 

twopoint
Figure 8 Response of two point scatterers. Note the flat spots.

The curves in Figure 8 include flat spots for the same reasons that some of the curves in Figures 6 and 7 were straight lines.

 

shell
Figure 9 Undocumented data from a recruitment brochure. This data may be assumed to be of textbook quality. The speed of sound in water is about 1500 m/sec. Identify the events at A, B, and C. Is this a common-shotpoint gather or a common-midpoint gather? (Shell Oil Company)