1        100.                   :reference station number and x-coord.
20.       0.                    :station spacing and receiver depth
41  42  43   80   240.  5700.   :shots  - s1 s2 s3 s4 output_xstation output_z
141 142 143 180   240.  5700.   :recvrs - r1 r2 r3 r4 output_xstation output_z
