This is the contents of the model geometry file:

1        100.                   :reference station number and x-coord.
20.       0.                    :station spacing and receiver depth
1   2   3   40    120.  2600.   :shots  - s1 s2 s3 s4 output_xstation output_z
101 102 103 140   120.  2600.   :recvrs - r1 r2 r3 r4 output_xstation output_z

We are adapting the CSHOT modeling program to this common offset
inversion application.  The "output_station" is the horizontal location
of the output point given as a station.  So the physical x = 100 + 120
* (20 - 1).  The z is the actual depth of the output point.

Those who are familiar with CSHOT will see that really we have first
put a shot at depth with receivers spanning stations 1-40 and then
fired a shot again at the same depth location with receivers spanning
101-140.  This clever idea is due to Zhenyue Liu.

Jack (07/11/91)
