Checking the Headers for Source and Geophone Polarizations( bdump)

The bdump program creates a partial header dump for a BSEGY file.

The normal ascending trace order I use is defined as:

1. down-hole V (vertical)
2. down-hole R (horizontal)
3. down-hole T (horizontal)
4. reference V (vertical)
5. reference R (horizontal)
6. reference T (horizontal)

See section 6.7.5 above, at the beginning of the genvsp run. If you don't use this order or its reverse, then you may have to modify the codes. We can check the files L141.seg and L142.seg (recall hodogram of Figure 12) to see if the headers have been formed correctly. Type:

bdump  L141.seg  0
less bdump.lst

the result is the partial header dump for file L141.seg as shown below:

{dumplist}
                     |-------------------------------|
                     |   PARTIAL SEGY HEADER DUMP    |
                     |                               |
                     |           L141.seg            |
                     |                               |
                     |-------------------------------|

 -----------------------------------------------------------------------------------
   Length =  2000 samples             |  Shot Elevation =        0.0
   Sample Interval =    0.00025 sec.  |  Shot Depth =        0.0
   Delay Time =    0 msec.            |  Up Hole Time =     0 msec
   Low Cut Filter  =    4 Hz.         |  Shot X-COORD =     100.00
   High Cut Filter = 1000 Hz.         |  Shot Y-COORD =     101.27
   Line ID: 0001                      |  Shot Date (year.day) = 1997.0715
   Shot Orientation:                  |  Shot Time (hr:min)   = 11:48
   Azimuth= 90 Deg.  Vertical=135 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 | 141| 001  421|   1.46|   -0.73    100.00    100.00| 3|0.0000|   20 |  0|  0|
    2 | 141| 001  422|   1.46|   -0.73    100.00    100.00| 3|0.0000|   20 |209| 90|
    3 | 141| 001  423|   1.46|   -0.73    100.00    100.00| 3|0.0000|   20 |299| 90|
    4 | 141| 001  424|   0.91|   -0.15    100.00    102.17| 3|0.0000|    0 |  0|  0|
    5 | 141| 001  425|   0.91|   -0.15    100.00    102.17| 3|0.0000|    0 |  0| 90|
    6 | 141| 001  426|   0.91|   -0.15    100.00    102.17| 3|0.0000|    0 |270| 90|

dumplist

Note that the two down-hole horizontal traces, 2 and 3, have azimuth R= $209^{o}$ and T= $299^{o}$ as determined in the Figure 12 hodogram. The dump for L142.seg is almost identical to that above, the only differences being the source polarization (which is azimuth=$270^{o}$ rather than $90^{o}$ as show here), and of course the time of day.