1             0.                       :reference station number and x-coord.
100.          0.                       :station spacing and receiver depth
21   30   31   120        21. 0.        :shot 1 - r1 r2 r3 r4 s sdepth
22   31   32   121        22. 0.
23   32   33   122        23. 0.
24   33   34   123        24. 0.
25   34   35   124        25. 0.
26   35   36   125        26. 0.
27   36   37   126        27. 0.
28   37   38   127        28. 0.
29   38   39   128        29. 0.
30   39   40   129        30. 0.
31   40   41   130        31. 0.
32   41   42   131        32. 0.
33   42   43   132        33. 0.
34   43   44   133        34. 0.
35   44   45   134        35. 0.
36   45   46   135        36. 0.
37   46   47   136        37. 0.
38   47   48   137        38. 0.
39   48   49   138        39. 0.
40   49   50   139        40. 0.
