NAME
trstat - may be used to generate a set of quality control
xgraph format files containing statistical information on
trace amplitude, frequency, decay and character useful in
automatically rejecting bad traces in a large [3D] dataset.
SYNOPSIS
trstat [ -Nntap ] [ -Ootap ] [ -nsnstr ] [ -nenetr ] [
-rsnrst ] [ -renred ] [ -sist ] [ -eiend ] [ -minaminamp ] [
-minarminampratio ] [ -mincminchar ] [ -mindmindecay ] [
-minfminfreq ] [ -minfamminfreqabovemute ] [ -minsminspecsum
] [ -fminspecminfreq ] [ -maxamaxamp ] [ -maxarmaxampratio ]
[ -maxcmaxchar ] [ -maxdmaxdecay ] [ -maxfmaxfreq ] [ -max-
fammaxfreqabovemute ] [ -maxsmaxspecsum ] [ -fmaxspecmaxfreq
] [ -qc ] [ -V ] [ -? or -h or -help ]
DESCRIPTION
trstat extracts trace-wise statistics from your input data
and, depending on the execution mode, outputs either a set
of quality control xgraph files or your data editted accord-
ing to a predetermined set of trace rejection criteria. In
quality control mode the routine generates the following
four histogram files which may be viewed using xgraph :
ntap.amplitude: shows a distribution based on trace-wise
average absolute amplitude
ntap.amplitudeRatio: shows a distribution based on the
Ratio of trace-wise average
absolute amplitudes above and below
the mute line defined by
-t0 and -v
ntap.frequency: shows a distribution based on trace-wise
zero crossing frequency
ntap.frequencyAbove: shows a distribution based on trace-
wise zero crossing frequency
above the line defined by -t0 and -v
ntap.decay: shows a distribution based on the db relation-
ship of the first and last half of the data window
ntap.character: shows a dimensionless measure trace charac-
ter based on the relationship of windowed average absolute
and median amplitudes
ntap.spectralSum: is an integration along a time - fre-
quency amplitude spectrum of each input trace. where ntap
is the fully qualified input filename. In the case of piped
input [or in IKP] the output xgraph file names will become:
trstat.amplitude
trstat.amplitudeRatio
trstat.frequency
trstat.frequencyAbove
trstat.decay
trstat.character
trstat.spectralSum
and the files will be dropped in the directory from which
the program was executed.
From the above plots it is possible to choose as set of
minimum and maximum parameters within which to pass data on
a subsequent execution of the program. During the rejection
run the above stats are store in the following trace header
locations so that the user may verify that the appropriate
action is being undertaken by the routine:
amplitude --> TVPT01
frequency --> TVPT02
character --> TVPT03
decay --> TVPT04
frequencyAbove --> TVPT05
amplitudeRatio --> TVPT06
TF spectralSum --> TVPT07
In choosing trace rejection limits a good rule of thumb is
to take the parameter cut-offs at the point where the histo-
gram amplitude falls to 2% of the maximum amplitude. This
rule of thumb was developed on a land 3D dataset of some
730,000 traces so it may vary from dataset to dataset.
Testing on a subset of representative data is strongly
recommended.
In execute mode the routine generates an additional output
xgraph file named:
otap.offset
where otap is the name of the output dataset. If no disk
output is attached the offset xgraph file will be:
trstat.offset
The plot shows the distribution of traces killed as a func-
tion of trace distance. Documented on this xgraph output is
also the total number of traces killed.
trstat gets both its data and its parameters from command
line arguments. These arguments specify the input, output,
the design window, the start and end traces, start and end
records, the execution mode, the minimum and maximum histo-
gram limits for any or all of the above categories and ver-
bose printout, if desired.
Command line arguments
-N ntap [default: stdin]
Enter the input data set name or file immediately after
typing -N unless the input is from a pipe in which case
the -N entry must be omitted. This input file should
include the complete path name if the file resides in a
different directory. Example -N/b/vsp/dummy tells the
program to look for file 'dummy' in directory '/b/vsp'.
-O otap [default: stdout]
Enter the output data set name or file immediately
after typing -O. This output file is not required when
piping the output to another process or when -qc is
present on the command line [see below].
-s ist [default: 0]
Enter the desired pass data start time in milliseconds.
-e iend [default: time of last sample on trace]
Enter the desired pass data end time in milliseconds.
-ns nstr [default: 1]
Enter the start trace number.
-ne netr [default: last trace of record]
Enter the end trace number.
-rs nrst [default: 1]
Enter start record number.
-re nred [default: last record]
Enter end record number.
-t0 tzero [default: 0]
Start Window Time in milliseconds. This will only be
used if -s above is not used.
-v winvel [default: flat]
Enter the window velocity in ft or meters per second.
-mina minamp [default: not used]
Enter the minimum amplitude to be passed. An entry for
-maxa below must also be present. Get these from the
ntap.amplitude histogram file [see above]. Traces
whose calculated amplitude parameter fall below this
value will be killed and a 30000 placed in the trace
header StaCor entry.
-minar minampratio [default: not used]
Enter the minimum amplitude ratio to be passed. An
entry for -maxar below must also be present. Get these
from the ntap.amplitudeRatio histogram file [see
above]. Traces whose calculated amplitude ratio param-
eter fall below this value will be killed and a 30000
placed in the trace header StaCor entry.
-minc minchar [default: not used]
Enter the minimum character to be passed. An entry for
-maxc below must also be present. Get this from the
ntap.character histogram file [see above]. Traces
whose calculated character parameter fall below this
value will be killed and a 30000 placed in the trace
header StaCor entry.
-mind mindecay [default: not used]
Enter the minimum decay to be passed. Get this from
the ntap.decay histogram file [see above]. Traces
whose calculated decay parameter fall below this value
will be killed and a 30000 placed in the trace header
StaCor entry.
-minf minfreq [default: not used]
Enter the minimum frequency to be passed. Get this
from the ntap.frequency histogram file [see above].
Traces whose calculated frequency parameter fall below
this value will be killed and a 30000 placed in the
trace header StaCor entry. If you wish to limit using
only a minimum frequency criteria you can do it but you
must also specify a maxf. In this case use a -maxf
entry greater than the maximum value seen on your qc
plot.
-minfam minfreqabovemute [default: not used]
Enter the minimum frequency above the mute zone to be
passed. Get this from the ntap.frequencyAbove histo-
gram file [see above]. Traces whose calculated fre-
quency parameter fall below this value will be killed
and a 30000 placed in the trace header StaCor entry. If
you wish to limit using only a minimum frequency cri-
teria you can do it but you must also specify a maxf.
In this case use a -maxf entry greater than the maximum
value seen on your qc plot.
-mins minspecsum [default: not used]
Enter the minimum Time - Frequency spectral sum ampli-
tude to be passed. Traces with spectral summations
less that this value will be killed and a 30000 placed
in the StaCor trace header entry.
-fmin specminfreq [default: 5]
Enter the minimum frequency over which the above spec-
tral sum will be calculated.
-maxa maxamp [default: not used]
Enter the maximum amplitude to be passed. An entry for
-mina above must also be present. Get this from the
ntap.amplitude histogram file [see above]. Traces
whose calculated amplitude parameter fall above this
value will be killed and a 30000 placed in the trace
header StaCor entry.
-maxar maxampratio [default: not used]
Enter the maximum amplitude ratio to be passed. Get
this from the ntap.amplitudeRatio histogram file [see
above]. Traces whose calculated amplitude parameter
fall above this value will be killed and a 30000 placed
in the trace header StaCor entry.
-maxc maxchar [default: not used]
Enter the maximum character to be passed. An entry for
-minc above must also be present. Get this from the
ntap.character histogram file [see above]. Traces
whose calculated character parameter fall above this
value will be killed and a 30000 placed in the trace
header StaCor entry.
-maxd maxdecay [default: not used]
Enter the maximum decay to be passed. Get this from
the ntap.decay histogram file [see above]. Traces
whose calculated decay parameter fall above this value
will be killed and a 30000 placed in the trace header
StaCor entry.
-maxf maxfreq [default: not used]
Enter the maximum frequency to be passed. Get this
from the ntap.frequency histogram file [see above].
Traces whose calculated frequency parameter fall above
this value will be killed and a 30000 placed in the
trace header StaCor entry.
-maxfam maxfreqabovemute [default: not used]
Enter the maximum frequency above the mute line to be
passed. Get this from the ntap.frequencyAbove histo-
gram file [see above]. Traces whose calculated fre-
quency parameter fall above this value will be killed
and a 30000 placed in the trace header StaCor entry.
-maxs maxspecsum [default: not used]
Enter the maximum Time - Frequency spectral sum ampli-
tude to be passed. Traces with spectral summations
greater that this value will be killed and a 30000
placed in the StaCor trace header entry.
-fmax specmaxfreq [default: 15]
Enter the maximum frequency over which the above spec-
tral sum will be calculated.
-qc Enter the command line argument '-qc' to generate the
quality control xgraph files [see above]. If not
included on the command line the program will attempt
to editt the dataset according to the minimum and max-
imum parameters entries made [see above].
-V Enter the command line argument '-V' to get additional
printout.
-? or -h or -help
Enter the command line argument '-?' or -h or -help
to get online help. The program terminates after the
help screen is printed.
BUGS
Unknown.
SEE ALSO
clean(1) glitches(1) skill(1) tfskill(1) fxbl(1) spbl(1)
AUTHOR
[Don Wagner: Socon 721-6042]
[USP implementation by Paul Garossino: March 95: Socon
422-3932]
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
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