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Rebecca was told to process some 1999 seismic data.  She nor
I where part of the data acquisition and there are no recorder's
logs.  She had several Exabyte tapes.  Here's how "we" proceeded:

1)  Ron Moe created a CD from one tape.  He used dd, so the tape
was in SEG-Y.  Ron had to use a CD because Rebecca's computer
doesn't have sftp.

To download the SEG-Y file (17.7MB): Mac users: OPTION-click on the filename below (right button if multibutton mouse). PC users: SHIFT-left-click on the filename below.

yr99jd85-0616z.segy

2)  What's in the file?
>lsd seisdata.1 1 5
SHOT   TR       RP    TR ID  RANGE DELAY NSAMPS    SI   YR DAY HR MIN SEC
 1     1       0     0  1      0  4000   6000  1000   99  85  6  16  48
 1     2       0     0  1      0  4000   6000  1000   99  85  6  16  48
 1     3       0     0  1      0  4000   6000  1000   99  85  6  16  48
 2     1       0     0  1      0  4000   6000  1000   99  85  6  16  59
 2     2       0     0  1      0  4000   6000  1000   99  85  6  16  59

Rename the file so it's more meaningful:
>mv seisdata.1 yr99jd85-0616z.segy

3)  The plot (script) has a space between every shot (3 traces)
and uses a generic .5 sec agc window.

4)  Adjust the parameters:
  a)  Use stime 6 and nsecs 2 to plot only the data of interest.
  b)  Use ann shotno taginc 3 to annotate the shot number on every
      third trace.

5)  Adding N traces together will reduce the random noise by SQRT(N).
While this reduces the horizontal resolution, I suspect the trace
spacing is small compared to the shot spacing.  A mix might not be 
good on data with steeply dipping events.
    Fake sioseis into thinking the data are cmp gathers rather
than shot gathers by using parameter ntrgat 3 in process diskin.
Sum the traces within the gather by using process stack.  Change
the plot parameters for displaying continuous subsurface (remove
fspace, spacei, nspace and change taginc).
    New script.

6)  I suspect these data were collected using GI guns as a source,
so try a filter passband of 20 250.  Adjust the plot horizontal
scale (parameter trpin) and reduce the trace amplitude (def).  Get
rid of plotting the trace wiggle (wiggle 0).  Overdrive and clip
the amplitudes (make def too big while limiting the deflection
by clipping it).
    Increase the agc window.
    New script.

7)  Too much clipping.  Decrease def and get rid of clip.  Also
note the trace blanking just prior to the water bottom, which
is caused by agc trying to make the noise in the water column
the same size as the water bottom.  Use agc parameter
center .1 to minimize that.  
    Adding a 3 trace mix will further reduce random noise by
SQRT(3).  Mix is a running average of adjacent traces.  It good
when there's not much dip but will "smear" whe dip is present.
    Script for new plot.

8)  On a different seismic line (over a seamount), the discussion
went:
    This mornings parameter changes for seisdata.2 are in plot.
Use stime 0 and nsecs 8.
    explanation:  sioseis plots a 3(?) trace gap whenever the
deep water delay changes (the time of the first sample in
the trace - why record the water column?).  By using stime 0,
sioseis forces every trace to the actual time by adding
zeroes.   

9)  Time to step back from the processing and think about the
geophysics and geology.   The extremely steep walls of the
seamount will not have sediment nor will there be any reflections
because the seismic energy wavepath is past the critical angle.
    The litle hyberbola (or frowns as we call them) are caused
by point sources - diffractors - faults and other discontinuities.
    Also, remember that seismics are omni-directional; what 
comes in first is not necessarily what's directly under the
ship.  It might be off to the side or in front or behind.
I filtered with pass 40 150 and noticed diffractors in the middle
of the seamount! 
    Hyberbolas can be collapsed with migration, but we'll need to
know the shot spacing.  The higher frequency of the diffractors
indicates that these are from the surface, so an fk migration
with water velocity might work great.
    The next step is to pick the water bottom with program sioplt 
so we can mute (zero) the water column and make prettier pictures 
for publication.