GENWAW

Basic Seismic Utilities (BSU) interactive program for setting geometry. Code optimal for a walk-a-way type of data collection. Code is for SEG-2 format (*.DAT) files. This code prompts the user for shot and geophone locations. It should be run in the directory where the SEG-2 *.DAT files are located. The code scans the directory contents and builds a list of the files needing to have headers corrected for geometry. One use that makes geometry setting less of a burden is to set geometry for temporary local coordinates (ex. line along x-axis), then employ BSU program BCRD to rotate and translate coordinates to a final system. This program is run if the SEG-2 headers were not correctly set during acquisition (a common occurance).

EXAMPLE:
Here, the application is a walk-a-way with a fixed source at 0,0,0 and a single moving vertical component geophone, starting at an offset of 10 meters walking in 1 meter steps toward the source. This is labor intensive, but very flexible.

  genwaw
Enter Number of Channels 1
GEOPHONE ORIENTATIONS
Geophone Az 90=East Ver 180=Down 
Channel=0 Enter Geophone Orientation  Az  Ver
0 180
     |----------------------------------------|
     |     Copyright (C) 2017 P. Michaels     |
     |           All rights reserved          |
     |     See GNU General Public License     |
     |----------------------------------------|
     waw:  TIME: 15:38:11 DATE: 29/May/2020 
Nsources= 10 
SOURCE LOCATION-------------------------------------
 0000.DAT: Enter Source X  Y  Z 
0 0 0
 Trace:00 Enter Receiver X  Y  Z 
10. 0 0
SOURCE LOCATION-------------------------------------
 0001.DAT: Enter Source X  Y  Z 
0 0 0
 Trace:00 Enter Receiver X  Y  Z 
9 0 0
SOURCE LOCATION-------------------------------------
 0002.DAT: Enter Source X  Y  Z 
0 0 0
 Trace:00 Enter Receiver X  Y  Z 
8. 0 0
. 
. etc....
.
SOURCE LOCATION-------------------------------------
 0009.DAT: Enter Source X  Y  Z 
0 0 0
 Trace:00 Enter Receiver X  Y  Z 
1.0 0 0

NOTE: If there were more than one trace in each *.DAT file, there would be additional “Trace:” questions to answer. Output includes the creation of a child directory, LST, in which the list files for each *.DAT file are stored. These are the result of the interactive program calling EGG2SEG 3.1.6. In this example, there will be files 0000.seg through 0009.seg, each with a single trace, now with headers as entered in GENWAW. To merge these into a single file, use BMRG (see 11.0.1). The command would be
bmrg 000 0 9 1 1 1
and that produces a file bmrg.seg. The headers can be checked by running BDUMP 4.0.1:

 
-----------------------------------------------------------------------------------
   Length =   500 samples             |  Shot Elevation =        0.0
   Sample Interval =    0.00100 sec.  |  Shot Depth =        0.0
   Delay Time =    0 msec.            |  Up Hole Time =     0 msec
   Low Cut Filter  =    0 Hz.         |  Shot X-COORD =       0.00
   High Cut Filter =  100 Hz.         |  Shot Y-COORD =       0.00
   Line ID:  000                      |  Shot Date (year.moday) = 2019.0423
   Shot Orientation:                  |  Shot Time (hr:min)   = 15:20
   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 |   0|0000 0001|  10.00|    0.00     10.00      0.00| 1|0.0000|   19 |  0|180|
    2 |   1|0000 0001|   9.00|    0.00      9.00      0.00| 1|0.0000|   19 |  0|180|
    3 |   2|0000 0001|   8.00|    0.00      8.00      0.00| 1|0.0000|   19 |  0|180|
    4 |   3|0000 0001|   7.00|    0.00      7.00      0.00| 1|0.0000|   19 |  0|180|
    5 |   4|0000 0001|   6.00|    0.00      6.00      0.00| 1|0.0000|   19 |  0|180|
    6 |   5|0000 0001|   5.00|    0.00      5.00      0.00| 1|0.0000|   19 |  0|180|
    7 |   6|0000 0001|   4.00|    0.00      4.00      0.00| 1|0.0000|   19 |  0|180|
    8 |   7|0000 0001|   3.00|    0.00      3.00      0.00| 1|0.0000|   19 |  0|180|
    9 |   8|0000 0001|   2.00|    0.00      2.00      0.00| 1|0.0000|   19 |  0|180|
   10 |   9|0000 0001|   1.00|    0.00      1.00      0.00| 1|0.0000|   19 |  0|180|

Figure 57: GENWAW: Example data from a small hammer source, trace equalized with BEQU 12.0.9.