The following obvious equation relates the traveltimes along the ray paths to source and geophone, t_{s} and t_{g}, to the given total traveltime t_{sg}:
t_{s} + t_{g} = t_{sg} . | (7) |
We can also state two more equations to account for the fact that the three ray paths, namely the zero-offset, source, and geophone ray paths, end at the same point in depth (R):
(8) |