The basic theory can be found in many engineering seismology text books. The following is a brief summary of how BSU implements the method. A highly simplified case is shown in Figure 32
The delay time equation for Shot A to geophone 1 is given by
where is the delay time at shot A, is the delay time at geophone 1, , is the horizontal distance between shot A and geophone 1, and is the observed travel time from shot A to geophone 1. The refractor velocity is . A complete system becomes, in matrix form, the following:
(25) |
or
Equation 24 is the first row of equation 26. Matrix is constructed by a program, bref, such that the first columns correspond to the shots, the other columns the geophones, ending in a last column giving the distance between a shot and receiver.