{genref} CDP Roll-a-long Pattern Generator Bison Format Data -----------SOURCES----------------------------- Enter 6 char. name for nez file (ex. STP001) REF001 Enter 4 char. LINEID 0001 Enter Z-Datum: Elevation 500. Enter number of shots 1 Enter Shot Record Names 8char: First LOST0001 Enter Shot Record Names 8char: Last LOST0001 Enter First Shot Station Number 01 Enter First Source: x, y, z 0, 0, 100. Enter Last Source: x, y, z 0, 0, 100. Enter number of receivers in a shot gather 12 Enter TOTAL NUMBER of stations on line 12 Enter First Geophone Station: x, y, z 0, 140., 100. Enter Last Geophone Station: x, y, z 0, 250., 100. Enter first shot NEAR GEOPHONE station 01 Enter first shot FAR GEOPHONE station 12genref
In this example, there is only one shot gather, Bison file named LOST0001. We are creating an *.nez file, REF001.nez. The Z-Datum is the elevation that all following elevations are measured from. Here, we set that to 500. Then later, the geophones and shots are specified as being 100. meters above that (final elevations are thus 600. meters). The generated file, REF001.nez is:
{name1} 0001 0.0000 0.0000 600.0000 SP001 0001 140.0000 0.0000 600.0000 VP001 0002 150.0000 0.0000 600.0000 VP002 0003 160.0000 0.0000 600.0000 VP003 0004 170.0000 0.0000 600.0000 VP004 0005 180.0000 0.0000 600.0000 VP005 0006 190.0000 0.0000 600.0000 VP006 0007 200.0000 0.0000 600.0000 VP007 0008 210.0000 0.0000 600.0000 VP008 0009 220.0000 0.0000 600.0000 VP009 0010 230.0000 0.0000 600.0000 VP010 0011 240.0000 0.0000 600.0000 VP011 0012 250.0000 0.0000 600.0000 VP012name1
The generated files geom, geom2, go1 must be set to executable using the
command
chmod +x g*
(assuming there are no other files starting with the
letter “g”). File geom has a record for each shot. Here, there is only
one line:
{name2} topcon REF001.nez LOST0001 0001 0.0 1 12 001 012 1 0. 0 0 0 0name2
The call to topcon captures sample interval, number of samples, date of shooting, etc from LOST0001, the Bison file. It combines that information with the REF001.nez file geometry to create a file LOST0001.xyz which is then needed later by script go1 which is called from geom2 shown next:
{name3} go1 001name3
Here is the script go1:
{name4} bis2seg LOST0$1 bhed LOST0$1.seg LOST0$1.xyz 0 mv bhedLOST.seg L$1.seg rm LOST0$1.segname4
$
In summary after running genref, make the scripts executable and run them
in sequence (geom, then geom2).
The result will be file L001.seg in this example. The program bdump produces a partial listing of the headers:
{name5} |-------------------------------| | PARTIAL SEGY HEADER DUMP | | | | L001.seg | | | |-------------------------------| ----------------------------------------------------------------------------------- Length = 2000 samples | Shot Elevation = 600.0 Sample Interval = 0.00020 sec. | Shot Depth = 0.0 Delay Time = 0 msec. | Up Hole Time = 0 msec Low Cut Filter = 16 Hz. | Shot X-COORD = 0.00 High Cut Filter = 500 Hz. | Shot Y-COORD = 0.00 Line ID: 0001 | Shot Date (year.moday) = 1992.0303 Shot Orientation: | Shot Time (hr:min) = 17:07 Azimuth= 0 Deg. Vertical= 0 Deg.| Charge Size (grams)= 0 ----------------------------------------------------------------------------------- TRACE|SHOT| STATION | OFFSET| RECEIVER |VERT|1STBRK|K-GAIN|AZI|VER| # |REC.|SHOT REC| | ELEV. X-COORD Y-COORD|FOLD|(SEC.)| (dB) | | | -----|----|---------|-------|----------------------------|--|------|------|---|---| 1 | 1|001 001 | 140.00| 600.00 0.00 140.00| 1|0.0000| 60 | 0| 0| 2 | 1|001 002 | 150.00| 600.00 0.00 150.00| 1|0.0000| 60 | 0| 0| 3 | 1|001 003 | 160.00| 600.00 0.00 160.00| 1|0.0000| 60 | 0| 0| 4 | 1|001 004 | 170.00| 600.00 0.00 170.00| 1|0.0000| 60 | 0| 0| 5 | 1|001 005 | 180.00| 600.00 0.00 180.00| 1|0.0000| 60 | 0| 0| 6 | 1|001 006 | 190.00| 600.00 0.00 190.00| 1|0.0000| 60 | 0| 0| 7 | 1|001 007 | 200.00| 600.00 0.00 200.00| 1|0.0000| 60 | 0| 0| 8 | 1|001 008 | 210.00| 600.00 0.00 210.00| 1|0.0000| 60 | 0| 0| 9 | 1|001 009 | 220.00| 600.00 0.00 220.00| 1|0.0000| 60 | 0| 0| 10 | 1|001 010 | 230.00| 600.00 0.00 230.00| 1|0.0000| 60 | 0| 0| 11 | 1|001 011 | 240.00| 600.00 0.00 240.00| 1|0.0000| 60 | 0| 0| 12 | 1|001 012 | 250.00| 600.00 0.00 250.00| 1|0.0000| 60 | 0| 0|name5
If there are any problems, or if one wishes to customize the geophone or shot orientations, that can be done by editing the *.xyz file and rerunning geom2. For setting down-hole data, see 6.7.5.