NAME
pickusp - pick reflections (same as pick)
SYNOPSIS
pickusp [ -Nntap ] [ -Eetap ] [ [ -Ccrdin ] [-mnlag MINLAG]
[-mxlag MAXLAG] [-ws IFWS] [-we WEND] [-fld FOLD] [-sw LW]
[-smn ISWMIN] [-smx ISWMAX] [-rgn MINRNG] [-rgx MAXRNG] [-
rs, -re IFRI, ILRI] [-st ILWS] [-pc IPRCNT] [-ni NUMITR] ]
DESCRIPTION
pickusp calculates the reflection time differences between
traces within a common depth point (CDP) gather. pickusp
produces an SIS format 5 event file suitable for input to
scor(1). Input to pickusp must be an SIS format 3 file con-
taining records which have been CDP sorted and corrected for
normal move-out. It is strongly recommended that de-
phasing, wavelet shaping (high-resolution deconvolution),
and/or predictive deconvolution be applied before input to
pickusp.
Optional parameter entry from the command line is provided
if the 1PICK card file name is not given.
Command line arguments
-N ntap
The path of an SIS format 3 file. If this field is
missing, standard input will be read if it is connected
to a pipe. If the file can not be accessed, an error
exit is taken.
-E etap
The path of the resulting event file. If this field is
missing, standard output will be written if it is con-
nected to a pipe. If the file can not be written to or
created, an error exit is taken.
-C crdin
The path of a file containing 1PICK cards (see below).
If this field is missing, it is assumed that startjob
is being used and the command string -pick.crd will be
searched for. Failure to provide one of these forms is
an error.
1PICK CARDS
A minimum of 1 and a maximum of 25 1PICK cards must be pro-
vided to control the operation of pickusp. The (fixed)
fields on these cards are described below.
(cc 1- 5) - 1PICK
The literal characters 1PICK must appear as the first
five characters of each card. Note that these charac-
ters must be in upper case.
(cc 7-15) - Large lag window
First card only. These entries define the minimum and
maximum lags, in ms, for cross-correlating an indivi-
dual trace with the reference trace and will determine
where the negative and positive peaks are to be found.
Card columns 7-10 specify the minimum time in ms, and
columns 12-15 the maximum. The default minimum is -120
ms. The default maximum is +120 ms.
(cc 16-20) - Trace window start time
Trace window start time in ms. If spatial interpola-
tion is requested, this entry is the window start time
for the first record to process (cc 52-56). If this
entry does not match the window start time on the pre-
vious card, the reference trace will be rebuilt using a
composite of the first record (cc 52-56) of the current
card.
(cc 21-25) - Trace window end time
Trace window end time in ms. Applies to first card
only. Maximum = [trace length in ms - 2 * (max of
large lag window)]. Window times exceeding the maximum
are reset to it. The absolute maximum trace window
length is 3000 samples. if (cc 21-25) is blank or 0,
the default is (window start time + 3000 samples -1 *
sample interval).
(cc 26-28) - Fold
First card only. Number of traces to use in the refer-
ence trace composite. Minimum 3, maximum 512. If this
field is blank or 0, the default is the fold from the
line header of the input file. The value can be
greater than the actual fold, allowing the crossing of
record boundaries.
(cc 30-32) - Smoothing window length
First card only. Length of the coherency smoothing
window, in samples, to use in a weighted composite. If
(cc 30-32) is blank or 0, the default is 1 + [(small
lag max - small lag min) * 3]/(sample interval).
(cc 33-41) - Small lag window
First card only. Minimum (cc 33-36) and maximum (cc
38-41) lags, in ms, for small lag window. Entries used
in determining where cross-correlation peaks are
expected to fall, relative to zero lag of the correla-
tion. Size of the window should be based on the
expected static, RNMO, and the period of the dominant
wavelet. If (cc 33-36) is blank or 0, the default is
-16 ms. If (cc 38-41) is blank or 0, the default is
+16 ms.
(cc 42-51) - Range limits
The minimum (cc 42-46) and maximum (cc 47-51) range, in
feet or meters, of traces to use in the picking compu-
tations. The defaults are 0 and 99999 respectively.
(cc 52-56) - First record number
Record number of the first record to process. For the
first card, the default is the first record of the
input file. Otherwise the default is one greater than
the record number (cc 57-61) of the previous card. If
this parameter exceeds the last record number of the
process value on the preceding card by more than 1, the
reference trace for correlating is rebuilt. If multi-
ple cards are used, any records not accounted for in
(cc 52-61) are given dead pick flags in their trace
headers (i.e. input records can be skipped).
(cc 57-61) - Last record number
Record number of the last record to process. Required
if spatial interpolation is requested (cc 62-66). Oth-
erwise, the default is the last record on the input
file.
(cc 62-66) - Window start time for last record
Optional. Completed to request spatial interpolation.
Enter window start time for record in 'last record
number' field. If this option is requested, interpola-
tion (window start time in cc 16-20 held constant).
(cc 76-76) - Print flag
First card only. Requests the printing of times,
weights and number of iterations by DI and GI if set to
1. The default is an abbreviated print.
(cc 77-78) - Percent bad picks
First card only. The percentage of bad picks to allow
before error terminating the job. This is percentage
of live input traces, within record and range limits,
which could not be picked. The default is to allow an
entirely dead file to be output.
(cc 79-80) - Number of iterations
Maximum number of iterations to allow to align indivi-
dual traces in a CDP. A maximum of 25 is allowed. The
default is (fold/2) + 3.
Optional Command Line Entry
Note that -ws, -rgn, -rgx, -rs, -re, -st, -ni may be
repeated as necessary to take into account variations of
these parameters along the line. Only those that change are
required to be filled in.
-mnlag MINLAG
Minimum large window lag (ms). Default = -120
-mxlag MAXLAG
Maximum large window lag (ms). Default = +120
-ws IFWS
Window start time (ms) on first record. Default is
first trace sample.
-we WEND
Window end time (ms) on first record. Default is last
trace sample. ws-we define the window length for the
job.
-fld FOLD
Fold. Default is line header entry.
-sw LW
Length (ms) of smoothing window. Default is length of
small lag window.
-smn ISWMIN
Minimum lag (ms) of small lag window. Default = -16
-smx ISWMAX
Maximum lag (ms) of small lag window. Default = +16
-rgn MINRNG
Minimum range limit (ft,m). Default is far negative
distance.
-rgx MAXRNG
Maximum range limit (ft,m). Default is far positive
distance.
-rs, -re IFRI, ILRI
Start and end records to pick. Default is first and
last records of data set.
-st ILWS
Start window time (ms) at last record (-re[]). Window
length remains the same. Default is the window start
time on the first record (-rs).
-pc IPRCNT
% bad picks to tolerate. Default = 100%
-ni NUMITR
Number iterations. Default = folld
SEE ALSO
scorusp(1), startjob(1), Amoco Seismic Information System
User Manual
BUGS
The UNIX implementation of pickusp does not support the use
of reference traces input from a separate file. A command
line option letter and its corresponding argument may not be
separated by whitespace.
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
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