A quality control check of the R/V New Horizon's Knudsen 3260 Sub-Bottom Profiler.

Also see:
Knudsen Engineering
October 2006 Sea Technology article pg1 pg2 pg3 - "Chirp Sub-Bottom Pr
ofiler Processing - A Review"
Knudsen Sub-Bottom Profiler bash scripts example.

Definitions:
    raw: digitized but unprocessed data, no correlation filtering 
         applied, no envelope detection;
    filtered: data that has been correlation filtered but not 
         envelope detected;
    detected: data that has been filtered and envelope detected.

Comments:
    The 3260 puts more information (metadata) in the segy headers and sioseis 
program lsd has a new option, -K, to list it.  e.g. lsd -K
    Note that the file name has 3.5kHz in it, yet lsd says:
  Sweep frequency at start (Hz).   2031
  Sweep frequency at end (Hz).   6031

Plot of the correlated chirp (2-6kHz.) with agc (.015sec).
Plot of the envelope with filter (100x700Hz.) and agc (.015sec).
Plot of envelope with swell filter, mix (1+1), filter (100x700Hz.), agc(.015sec)
Depth Plot of envelope with swell filter, mix (1+1), filter (100x700Hz.), agc(.015sec)
mkenv - Make an envelope file from a correlate file.
gzipped raw file 2009_275_1825_70873_3.5kHz_000.sgy
	

The sioseis swell script:
#!/bin/bash -f
rm sunfil.ras
sioseis << eof
procs diskin wbt prout swell mix filter agc plot end
diskin
   ipath env-2009_275_1825_70873_3.5kHz_000.sgy end
end
swell
   n 51 end
end
agc
   winlen .015 end
end
wbt
   vel 1500 end
end
mix
   weight 1  1 end
end
filter
    ftype 0 pass 100 700 dbdrop 48 end
end
prout
    fno 0 lno 9999999 noinc 100 end
end
plot
  stime .05 nsecs .1
   dir ltr dptr 1 tlines .05 .1 ! chart 5 75
    colors gray opath siofil wiggle 0  ann gmtint anninc 1
    trpin 300 def .02 tlines .05 vscale 20 end
end
end
eof
sio2sun siofil sunfil.ras
display -rotate 270 sunfil.ras &