Go to the list of seismic processes. Go to SIOSEIS introduction.
Steve,
    I tried to simulate what I think you want to accomplish.
Basically it's what I think is called a "walkaway" shoot in exploration.
The cable is stationary and the shots move.
    The following is an example of a walkaway.  The trick is to use geom
type 1, which adds DFLS to the previous shot's x-coordinate to obtain the
x-coordinate for the current shot.  Then use GXP to establish the receiver
x-coordinates.
    The example below moves the shots around alot in order to show that
the RP calculation is ok and that dead traces are inserted when no
traces contribute to an RP.

Paul


 SIOSEIS ver 96.9 (5 Dec. 1996) (C) Regents of U.C.                             
procs syn geom gather stack diskoa end 
syn 
  fno 101 lno 105 
   secs 1 ntrcs 20 tva .5 1000 1 end 
end 
geom 
  gxp 1 -2900 20 -1000  ggx 100 lprint 2 dbrps 50 type 1 
   fs 101 ls 101 end 
  fs 102 ls 102 gxp 1 -3400 20 -1500 dfls 500 end 
   fs 103 ls 103 gxp 1 -4400 20 -2500 dfls 1000 end 
   fs 104 ls 104 gxp 1 -6700 20 -4800 dfls 2300 end 
   fs 105 ls 105 gxp 1 -7300 20 -5400 dfls 600 end 
end 
gather 
   end 
end 
diskoa 
   opath test end 
end 
end 
 ****    0 ERRORS IN THIS JOB   ****
 SHOT      101 TRACE        1 HAS RANGE    -2900, CDP NUMBER      274, SHOT COORD    15150, RECEIVER COORD    12250
 SHOT      101 TRACE        2 HAS RANGE    -2800, CDP NUMBER      275, SHOT COORD    15150, RECEIVER COORD    12350
 SHOT      101 TRACE        3 HAS RANGE    -2700, CDP NUMBER      276, SHOT COORD    15150, RECEIVER COORD    12450
 SHOT      101 TRACE        4 HAS RANGE    -2600, CDP NUMBER      277, SHOT COORD    15150, RECEIVER COORD    12550
 SHOT      101 TRACE        5 HAS RANGE    -2500, CDP NUMBER      278, SHOT COORD    15150, RECEIVER COORD    12650
 SHOT      101 TRACE        6 HAS RANGE    -2400, CDP NUMBER      279, SHOT COORD    15150, RECEIVER COORD    12750
 SHOT      101 TRACE        7 HAS RANGE    -2300, CDP NUMBER      280, SHOT COORD    15150, RECEIVER COORD    12850
 SHOT      101 TRACE        8 HAS RANGE    -2200, CDP NUMBER      281, SHOT COORD    15150, RECEIVER COORD    12950
 SHOT      101 TRACE        9 HAS RANGE    -2100, CDP NUMBER      282, SHOT COORD    15150, RECEIVER COORD    13050
 SHOT      101 TRACE       10 HAS RANGE    -2000, CDP NUMBER      283, SHOT COORD    15150, RECEIVER COORD    13150
 SHOT      101 TRACE       11 HAS RANGE    -1900, CDP NUMBER      284, SHOT COORD    15150, RECEIVER COORD    13250
 SHOT      101 TRACE       12 HAS RANGE    -1800, CDP NUMBER      285, SHOT COORD    15150, RECEIVER COORD    13350
 SHOT      101 TRACE       13 HAS RANGE    -1700, CDP NUMBER      286, SHOT COORD    15150, RECEIVER COORD    13450
 SHOT      101 TRACE       14 HAS RANGE    -1600, CDP NUMBER      287, SHOT COORD    15150, RECEIVER COORD    13550
 SHOT      101 TRACE       15 HAS RANGE    -1500, CDP NUMBER      288, SHOT COORD    15150, RECEIVER COORD    13650
 SHOT      101 TRACE       16 HAS RANGE    -1400, CDP NUMBER      289, SHOT COORD    15150, RECEIVER COORD    13750
 SHOT      101 TRACE       17 HAS RANGE    -1300, CDP NUMBER      290, SHOT COORD    15150, RECEIVER COORD    13850
 SHOT      101 TRACE       18 HAS RANGE    -1200, CDP NUMBER      291, SHOT COORD    15150, RECEIVER COORD    13950
 SHOT      101 TRACE       19 HAS RANGE    -1100, CDP NUMBER      292, SHOT COORD    15150, RECEIVER COORD    14050
 SHOT      101 TRACE       20 HAS RANGE    -1000, CDP NUMBER      293, SHOT COORD    15150, RECEIVER COORD    14150
 SHOT      102 TRACE        1 HAS RANGE    -3400, CDP NUMBER      279, SHOT COORD    15650, RECEIVER COORD    12250
 SHOT      102 TRACE        2 HAS RANGE    -3300, CDP NUMBER      280, SHOT COORD    15650, RECEIVER COORD    12350
 SHOT      102 TRACE        3 HAS RANGE    -3200, CDP NUMBER      281, SHOT COORD    15650, RECEIVER COORD    12450
 SHOT      102 TRACE        4 HAS RANGE    -3100, CDP NUMBER      282, SHOT COORD    15650, RECEIVER COORD    12550
 SHOT      102 TRACE        5 HAS RANGE    -3000, CDP NUMBER      283, SHOT COORD    15650, RECEIVER COORD    12650
 SHOT      102 TRACE        6 HAS RANGE    -2900, CDP NUMBER      284, SHOT COORD    15650, RECEIVER COORD    12750
 SHOT      102 TRACE        7 HAS RANGE    -2800, CDP NUMBER      285, SHOT COORD    15650, RECEIVER COORD    12850
 SHOT      102 TRACE        8 HAS RANGE    -2700, CDP NUMBER      286, SHOT COORD    15650, RECEIVER COORD    12950
 SHOT      102 TRACE        9 HAS RANGE    -2600, CDP NUMBER      287, SHOT COORD    15650, RECEIVER COORD    13050
 SHOT      102 TRACE       10 HAS RANGE    -2500, CDP NUMBER      288, SHOT COORD    15650, RECEIVER COORD    13150
 SHOT      102 TRACE       11 HAS RANGE    -2400, CDP NUMBER      289, SHOT COORD    15650, RECEIVER COORD    13250
 SHOT      102 TRACE       12 HAS RANGE    -2300, CDP NUMBER      290, SHOT COORD    15650, RECEIVER COORD    13350
 SHOT      102 TRACE       13 HAS RANGE    -2200, CDP NUMBER      291, SHOT COORD    15650, RECEIVER COORD    13450
 SHOT      102 TRACE       14 HAS RANGE    -2100, CDP NUMBER      292, SHOT COORD    15650, RECEIVER COORD    13550
 SHOT      102 TRACE       15 HAS RANGE    -2000, CDP NUMBER      293, SHOT COORD    15650, RECEIVER COORD    13650
 SHOT      102 TRACE       16 HAS RANGE    -1900, CDP NUMBER      294, SHOT COORD    15650, RECEIVER COORD    13750
 SHOT      102 TRACE       17 HAS RANGE    -1800, CDP NUMBER      295, SHOT COORD    15650, RECEIVER COORD    13850
 SHOT      102 TRACE       18 HAS RANGE    -1700, CDP NUMBER      296, SHOT COORD    15650, RECEIVER COORD    13950
 SHOT      102 TRACE       19 HAS RANGE    -1600, CDP NUMBER      297, SHOT COORD    15650, RECEIVER COORD    14050
 SHOT      102 TRACE       20 HAS RANGE    -1500, CDP NUMBER      298, SHOT COORD    15650, RECEIVER COORD    14150
 SHOT      103 TRACE        1 HAS RANGE    -4400, CDP NUMBER      289, SHOT COORD    16650, RECEIVER COORD    12250
 SHOT      103 TRACE        2 HAS RANGE    -4300, CDP NUMBER      290, SHOT COORD    16650, RECEIVER COORD    12350
 SHOT      103 TRACE        3 HAS RANGE    -4200, CDP NUMBER      291, SHOT COORD    16650, RECEIVER COORD    12450
 SHOT      103 TRACE        4 HAS RANGE    -4100, CDP NUMBER      292, SHOT COORD    16650, RECEIVER COORD    12550
 SHOT      103 TRACE        5 HAS RANGE    -4000, CDP NUMBER      293, SHOT COORD    16650, RECEIVER COORD    12650
 SHOT      103 TRACE        6 HAS RANGE    -3900, CDP NUMBER      294, SHOT COORD    16650, RECEIVER COORD    12750
 SHOT      103 TRACE        7 HAS RANGE    -3800, CDP NUMBER      295, SHOT COORD    16650, RECEIVER COORD    12850
 SHOT      103 TRACE        8 HAS RANGE    -3700, CDP NUMBER      296, SHOT COORD    16650, RECEIVER COORD    12950
 SHOT      103 TRACE        9 HAS RANGE    -3600, CDP NUMBER      297, SHOT COORD    16650, RECEIVER COORD    13050
 SHOT      103 TRACE       10 HAS RANGE    -3500, CDP NUMBER      298, SHOT COORD    16650, RECEIVER COORD    13150
 SHOT      103 TRACE       11 HAS RANGE    -3400, CDP NUMBER      299, SHOT COORD    16650, RECEIVER COORD    13250
 SHOT      103 TRACE       12 HAS RANGE    -3300, CDP NUMBER      300, SHOT COORD    16650, RECEIVER COORD    13350
 SHOT      103 TRACE       13 HAS RANGE    -3200, CDP NUMBER      301, SHOT COORD    16650, RECEIVER COORD    13450
 SHOT      103 TRACE       14 HAS RANGE    -3100, CDP NUMBER      302, SHOT COORD    16650, RECEIVER COORD    13550
 SHOT      103 TRACE       15 HAS RANGE    -3000, CDP NUMBER      303, SHOT COORD    16650, RECEIVER COORD    13650
 SHOT      103 TRACE       16 HAS RANGE    -2900, CDP NUMBER      304, SHOT COORD    16650, RECEIVER COORD    13750
 SHOT      103 TRACE       17 HAS RANGE    -2800, CDP NUMBER      305, SHOT COORD    16650, RECEIVER COORD    13850
 SHOT      103 TRACE       18 HAS RANGE    -2700, CDP NUMBER      306, SHOT COORD    16650, RECEIVER COORD    13950
 SHOT      103 TRACE       19 HAS RANGE    -2600, CDP NUMBER      307, SHOT COORD    16650, RECEIVER COORD    14050
 SHOT      103 TRACE       20 HAS RANGE    -2500, CDP NUMBER      308, SHOT COORD    16650, RECEIVER COORD    14150
 SHOT      104 TRACE        1 HAS RANGE    -6700, CDP NUMBER      312, SHOT COORD    18950, RECEIVER COORD    12250
 SHOT      104 TRACE        2 HAS RANGE    -6600, CDP NUMBER      313, SHOT COORD    18950, RECEIVER COORD    12350
 SHOT      104 TRACE        3 HAS RANGE    -6500, CDP NUMBER      314, SHOT COORD    18950, RECEIVER COORD    12450
 SHOT      104 TRACE        4 HAS RANGE    -6400, CDP NUMBER      315, SHOT COORD    18950, RECEIVER COORD    12550
 SHOT      104 TRACE        5 HAS RANGE    -6300, CDP NUMBER      316, SHOT COORD    18950, RECEIVER COORD    12650
 SHOT      104 TRACE        6 HAS RANGE    -6200, CDP NUMBER      317, SHOT COORD    18950, RECEIVER COORD    12750
 SHOT      104 TRACE        7 HAS RANGE    -6100, CDP NUMBER      318, SHOT COORD    18950, RECEIVER COORD    12850
 SHOT      104 TRACE        8 HAS RANGE    -6000, CDP NUMBER      319, SHOT COORD    18950, RECEIVER COORD    12950
 SHOT      104 TRACE        9 HAS RANGE    -5900, CDP NUMBER      320, SHOT COORD    18950, RECEIVER COORD    13050
 SHOT      104 TRACE       10 HAS RANGE    -5800, CDP NUMBER      321, SHOT COORD    18950, RECEIVER COORD    13150
 SHOT      104 TRACE       11 HAS RANGE    -5700, CDP NUMBER      322, SHOT COORD    18950, RECEIVER COORD    13250
 SHOT      104 TRACE       12 HAS RANGE    -5600, CDP NUMBER      323, SHOT COORD    18950, RECEIVER COORD    13350
 SHOT      104 TRACE       13 HAS RANGE    -5500, CDP NUMBER      324, SHOT COORD    18950, RECEIVER COORD    13450
 SHOT      104 TRACE       14 HAS RANGE    -5400, CDP NUMBER      325, SHOT COORD    18950, RECEIVER COORD    13550
 SHOT      104 TRACE       15 HAS RANGE    -5300, CDP NUMBER      326, SHOT COORD    18950, RECEIVER COORD    13650
 SHOT      104 TRACE       16 HAS RANGE    -5200, CDP NUMBER      327, SHOT COORD    18950, RECEIVER COORD    13750
 SHOT      104 TRACE       17 HAS RANGE    -5100, CDP NUMBER      328, SHOT COORD    18950, RECEIVER COORD    13850
 SHOT      104 TRACE       18 HAS RANGE    -5000, CDP NUMBER      329, SHOT COORD    18950, RECEIVER COORD    13950
 SHOT      104 TRACE       19 HAS RANGE    -4900, CDP NUMBER      330, SHOT COORD    18950, RECEIVER COORD    14050
 SHOT      104 TRACE       20 HAS RANGE    -4800, CDP NUMBER      331, SHOT COORD    18950, RECEIVER COORD    14150
 SHOT      105 TRACE        1 HAS RANGE    -7300, CDP NUMBER      318, SHOT COORD    19550, RECEIVER COORD    12250
 SHOT      105 TRACE        2 HAS RANGE    -7200, CDP NUMBER      319, SHOT COORD    19550, RECEIVER COORD    12350
 SHOT      105 TRACE        3 HAS RANGE    -7100, CDP NUMBER      320, SHOT COORD    19550, RECEIVER COORD    12450
 SHOT      105 TRACE        4 HAS RANGE    -7000, CDP NUMBER      321, SHOT COORD    19550, RECEIVER COORD    12550
 SHOT      105 TRACE        5 HAS RANGE    -6900, CDP NUMBER      322, SHOT COORD    19550, RECEIVER COORD    12650
 SHOT      105 TRACE        6 HAS RANGE    -6800, CDP NUMBER      323, SHOT COORD    19550, RECEIVER COORD    12750
 SHOT      105 TRACE        7 HAS RANGE    -6700, CDP NUMBER      324, SHOT COORD    19550, RECEIVER COORD    12850
 SHOT      105 TRACE        8 HAS RANGE    -6600, CDP NUMBER      325, SHOT COORD    19550, RECEIVER COORD    12950
 SHOT      105 TRACE        9 HAS RANGE    -6500, CDP NUMBER      326, SHOT COORD    19550, RECEIVER COORD    13050
 SHOT      105 TRACE       10 HAS RANGE    -6400, CDP NUMBER      327, SHOT COORD    19550, RECEIVER COORD    13150
 SHOT      105 TRACE       11 HAS RANGE    -6300, CDP NUMBER      328, SHOT COORD    19550, RECEIVER COORD    13250
 SHOT      105 TRACE       12 HAS RANGE    -6200, CDP NUMBER      329, SHOT COORD    19550, RECEIVER COORD    13350
 SHOT      105 TRACE       13 HAS RANGE    -6100, CDP NUMBER      330, SHOT COORD    19550, RECEIVER COORD    13450
 SHOT      105 TRACE       14 HAS RANGE    -6000, CDP NUMBER      331, SHOT COORD    19550, RECEIVER COORD    13550
 SHOT      105 TRACE       15 HAS RANGE    -5900, CDP NUMBER      332, SHOT COORD    19550, RECEIVER COORD    13650
 SHOT      105 TRACE       16 HAS RANGE    -5800, CDP NUMBER      333, SHOT COORD    19550, RECEIVER COORD    13750
 SHOT      105 TRACE       17 HAS RANGE    -5700, CDP NUMBER      334, SHOT COORD    19550, RECEIVER COORD    13850
 SHOT      105 TRACE       18 HAS RANGE    -5600, CDP NUMBER      335, SHOT COORD    19550, RECEIVER COORD    13950
 SHOT      105 TRACE       19 HAS RANGE    -5500, CDP NUMBER      336, SHOT COORD    19550, RECEIVER COORD    14050
 SHOT      105 TRACE       20 HAS RANGE    -5400, CDP NUMBER      337, SHOT COORD    19550, RECEIVER COORD    14150
 END OF SIOSEIS RUN
      SHOT    TR    RP    TR ID  RANGE DELAY NSAMPS    SI   YR DAY HR MIN SEC EOG
       101     1   274     1  1  -2900     0    251  4000    0   0  0   0   0   0
       101     2   275     1  1  -2800     0    251  4000    0   0  0   0   0   0
       101     3   276     1  1  -2700     0    251  4000    0   0  0   0   0   0
       101     4   277     1  1  -2600     0    251  4000    0   0  0   0   0   0
       101     5   278     1  1  -2500     0    251  4000    0   0  0   0   0   0
       102     1   279     1  1  -3400     0    251  4000    0   0  0   0   0   0
       102     2   280     1  1  -3300     0    251  4000    0   0  0   0   0   0
       102     3   281     1  1  -3200     0    251  4000    0   0  0   0   0   0
       102     4   282     1  1  -3100     0    251  4000    0   0  0   0   0   0
       102     5   283     1  1  -3000     0    251  4000    0   0  0   0   0   0
       102     6   284     1  1  -2900     0    251  4000    0   0  0   0   0   0
       102     7   285     1  1  -2800     0    251  4000    0   0  0   0   0   0
       102     8   286     1  1  -2700     0    251  4000    0   0  0   0   0   0
       102     9   287     1  1  -2600     0    251  4000    0   0  0   0   0   0
       102    10   288     1  1  -2500     0    251  4000    0   0  0   0   0   0
       103     1   289     1  1  -4400     0    251  4000    0   0  0   0   0   0
       103     2   290     1  1  -4300     0    251  4000    0   0  0   0   0   0
       103     3   291     1  1  -4200     0    251  4000    0   0  0   0   0   0
       103     4   292     1  1  -4100     0    251  4000    0   0  0   0   0   0
       103     5   293     1  1  -4000     0    251  4000    0   0  0   0   0   0
       103     6   294     1  1  -3900     0    251  4000    0   0  0   0   0   0
       103     7   295     1  1  -3800     0    251  4000    0   0  0   0   0   0
       103     8   296     1  1  -3700     0    251  4000    0   0  0   0   0   0
       103     9   297     1  1  -3600     0    251  4000    0   0  0   0   0   0
       103    10   298     1  1  -3500     0    251  4000    0   0  0   0   0   0
       103    11   299     1  1  -3400     0    251  4000    0   0  0   0   0   0
       103    12   300     1  1  -3300     0    251  4000    0   0  0   0   0   0
       103    13   301     1  1  -3200     0    251  4000    0   0  0   0   0   0
       103    14   302     1  1  -3100     0    251  4000    0   0  0   0   0   0
       103    15   303     1  1  -3000     0    251  4000    0   0  0   0   0   0
       103    16   304     1  1  -2900     0    251  4000    0   0  0   0   0   0
       103    17   305     1  1  -2800     0    251  4000    0   0  0   0   0   0
       103    18   306     1  1  -2700     0    251  4000    0   0  0   0   0   0
       103    19   307     1  1  -2600     0    251  4000    0   0  0   0   0   0
       103    20   308     1  1  -2500     0    251  4000    0   0  0   0   0   0
       105    17   309     1  2  -5700     0    251  4000    0   0  0   0   0   0
       105    18   310     1  2  -5600     0    251  4000    0   0  0   0   0   0
       105    19   311     1  2  -5500     0    251  4000    0   0  0   0   0   0
       104     1   312     1  1  -6700     0    251  4000    0   0  0   0   0   0
       104     2   313     1  1  -6600     0    251  4000    0   0  0   0   0   0
       104     3   314     1  1  -6500     0    251  4000    0   0  0   0   0   0
       104     4   315     1  1  -6400     0    251  4000    0   0  0   0   0   0
       104     5   316     1  1  -6300     0    251  4000    0   0  0   0   0   0
       104     6   317     1  1  -6200     0    251  4000    0   0  0   0   0   0
       105     1   318     1  1  -7300     0    251  4000    0   0  0   0   0   0
       105     2   319     1  1  -7200     0    251  4000    0   0  0   0   0   0
       105     3   320     1  1  -7100     0    251  4000    0   0  0   0   0   0
       105     4   321     1  1  -7000     0    251  4000    0   0  0   0   0   0
       105     5   322     1  1  -6900     0    251  4000    0   0  0   0   0   0
       105     6   323     1  1  -6800     0    251  4000    0   0  0   0   0   0
       105     7   324     1  1  -6700     0    251  4000    0   0  0   0   0   0
       105     8   325     1  1  -6600     0    251  4000    0   0  0   0   0   0
       105     9   326     1  1  -6500     0    251  4000    0   0  0   0   0   0
       105    10   327     1  1  -6400     0    251  4000    0   0  0   0   0   0
       105    11   328     1  1  -6300     0    251  4000    0   0  0   0   0   0
       105    12   329     1  1  -6200     0    251  4000    0   0  0   0   0   0
       105    13   330     1  1  -6100     0    251  4000    0   0  0   0   0   0
       105    14   331     1  1  -6000     0    251  4000    0   0  0   0   0   0
       105    15   332     1  1  -5900     0    251  4000    0   0  0   0   0   0
       105    16   333     1  1  -5800     0    251  4000    0   0  0   0   0   0
       105    17   334     1  1  -5700     0    251  4000    0   0  0   0   0   0
       105    18   335     1  1  -5600     0    251  4000    0   0  0   0   0   0
       105    19   336     1  1  -5500     0    251  4000    0   0  0   0   0   0