NAME
tim2hed3d - read workstation event file and stuff times or
depths into trace headers based on XYs
SYNOPSIS
tim2hed3d [ -Nntap ] [ -Ootap ] [ -Pptap ] [ -x1x1 ] [ -y1y1
] [ -x2x2 ] [ -y2y2 ] [ -x3x3 ] [ -y3y3 ] [ -x4x4 ] [ -y4y4
] [ -cldmcldm ] [ -ildmildm ] [ -RC ] [ -diminmindi ] [
-dimaxmaxdi ] [ -dideldidel ] [ -liminminli ] [ -limaxmaxli
] [ -lidellidel ] [ -stk ] [ -swstawrdm ] [ -flt ] [ -tstscl
] [ -f2m ] [ -m2f ] [ -xsd ] [ [ -FT ] [ -ordord ] [ -iter-
iter ] [ -itypityp ] [ -SM ] [ -nfnf ] [ -QC ] [ -QCUSP ] [
-Fftap ] [ -DF ] ] [ -I ] [ -E ] [ -V ] [ -? ]
DESCRIPTION
tim2hed3d takes input seismc data and based on XY locations
[or alternately, record and trace numbering] of traces
extracted from an attached file times or depths and stuffs
the values into a user specified trace header word. Before
any seismic traces are read the entire control file is
scanned and only those times/depths falling within the user
specified coordinate box are used. These are put into a
matrix and interpolated/extrapolated out to the edges of the
users survey box (unless instructed not to). As traces are
read their XY locations are used to find a location in the
time/depth matrix from which the appropriate value is
extracted. This value is then written into the trace header
word.
There are options to fit a surface to the input times or to
median smooth the times. The surface fitting can be done
using either a robust fitter which tends to ignore sudden
localized deviations in the overall surface or a least
squares approach which tends to honor such deviations.
Unless flagged with -RC the input seismic traces must have
the source and receiver XYs, RcPtXC, RcPtYC, SrPtXC, SrPtYC,
properly filled in. These coordinates must given in the same
system as the workstation event file. If flagged with -RC
the RecNum, TrcNum indexing will be used to reference the
surface described in the control file.
tim2hed3d gets both its data and its parameters from command
line arguments. These arguments specify the input and out-
put seismic files, the surface control file, survey corner
locations, LI & DI limits, the trace header word, trace
header word format, format of control file, coordinates
flag, surface fit parameters, quality control output flag,
application type and verbose printout, if desired.
Command line arguments
-N ntap
Enter the name of the input seismic data. Default is
to read from stdin (pipe). The traces must have valid
source and receiver XYs (i.e. locations RcPtXC, RcPtYC,
SrPtXC, SrPtYC filled in).
-P ptap
Enter the name of the surface control file. Currently
the file must either be 5 column format: records,
traces (or the reverse), X, Y, time or depth, a stan-
dard xsd pick file, an extended xsd header pick file
with CDPBCX and CDPBCY filled in (it is assumed here
that picks have been made on a stack section or offset
volume), or as a usp format file. If the file is usp
format it must have a single record (for the one hor-
izon) and the number of samples per trace must be equal
to the number of DIs of the survey of interest and the
number of trace must be equal to the number of LIs of
the survay. If in XY pick format the XYs must be in the
same coordinate system as the input seismic data abd in
this case data lying outside the defined box will have
no value inserted in its headers.
-O otap
Enter the name of the output seismic data. Default is
stdout (pipe).
-F ftap
Enter the name of the optional output QC file. This
will either be an ascii file (-QC flag) or a usp format
file (-QCUSP flag). Default file name for the ascii
option will be TIMHED. Default file name for the usp
format will be TIMHED.usp (which will have one record
for no smoothing and two records for smoothing). If a
usp format file then it can be sujected to general pro-
cessing tools.
-x1x1, -y1y1, -x2x2, -y2y2, -x3x3, -y3y3, -x4x4, -y4y4
Enter the area of interest over the survey with the X-Y
coordinates (ft,m) defining the four corners of a
parallelogram on the ground. Going either clockwise or
counter clockwise (clockwise recommended) from Corner 1
the first move to Corner 2 should be in the direction
of a receiver or shot line. The direction 1-2 will
always define the Y or DI direction. The DIs will
always start from side 1-4 and increase in the 1-2 (Y)
direction; the LIs will always start from side 1-2 and
increase in the 1-4 (X) direction. The values must be
the same units as those given in the source, receiver,
and midpoint X-Ys in the trace headers.
-cldm cldm
Enter the crossline (along X or side 2-3) cell
dimension (ft,m). For most shooting geometries this
will be 1/2 the line or group spacing depending on the
orientation of side 2-3 with respect to the receiver
lines. The sides are defined to be X along side 1-4
(roughly cross-line direction), Y along side 1-2
(roughly in-line direction). Remember when setting up
the coordinate system the line joining Corner (1) to
Corner (2) should be in the direction of a receiver or
shot line. No default.
-ildm ildm
Enter the inline (along Y or side 1-2) cell dimension
(ft,m). For most recording geometries this will be 1/2
the line or group spacing depending on the orientation
of side 1-2 with respect to the receiver lines. The
sides are defined to be X along side 1-4 (roughly
cross-line direction), Y along side 1-2 (roughly in-
line direction). Remember when setting up the coordi-
nate system the line joining Corner (1) to Corner (2)
should be in the direction of a receiver or shot line.
No default.
-RC Enter the command line argument '-RC' to use the line
and trace numbers out of the surface control file. In
this case no XYs will be needed. The RecNum and TrcNum
entries in the input seismic data will be assumed to be
numbered in a manner appropriate to the horizon file.
Default is to use XYs in surface control file.
-limin, limax minli, maxli
For -RC option: enter the minimum and maximum line
indexes to output. The output survey will have so many
bins in the inline direction as detmernined by the for-
mula NLI = (maxli - minli)/lidel + 1. Default minli =
1.
-lidel lidel
For -RC option: enter the LI increment. The total
number of lines will be determined by the formula NLI =
(maxli - minli)/lidel + 1. Default = 1.
-dimin, dimax mindi, maxdi
For -RC option: enter the minimum and maximum crossline
indexes to output. The output survey will have so many
bins in the crossline direction as detmernined by the
formula NDI = (maxdi - mindi)/didel + 1. Default mindi
= 1.
-didel didel
For -RC option: enter the DI increment. The total
number of crosslines will be determined by the formula
NDI = (maxdi - mindi)/didel + 1
-stk Enter the command line argument '-stk' if input data is
stacked volume with valid CDPBCX & CDPBCY bin center
header words filled in.
-sw stawrd
Enter the trace header word mnemonic to capture the
times/depths. Default = StaCor
-flt Enter the command line argument '-flt' if you wish to
store the times in the trace headers as floating point
values. Suggested floating point words are Horz01 ...
Horz08. If you do you must remember to flag downstream
programs, e.g. rest, that the word is a float.
-ts tscl
Enter time scale factor. All times will be multiplied
by this amount and it will be put into the line header
entry T_Unit. Although a floating point value it should
be kept in mind it will be stored as an integer so
values should be 2, 5, 10, etc. CAUTION: do not use too
large a scale factor if you are storing the times in a
short integer (I*2) trace header word. You are limited
to absolute values of roughly 32000. Default = 1.
-xsd Enter the command line argument '-xsd' if the surface
control file is a standard xsd pickfile or an extended
xsd header pick file made on a stack section or offset
volume. The extended pick file must have been saved
with the bin center XYs CDPBCX and CDPBCY filled in as
the routine is set to key on those header word mnemon-
ics in the extended pick file reader. A standard xsd
pickfile may simply use sequential record and trace
number.
-usp Enter the command line argument '-usp' if the surface
control file is a usp format data set. It must consist
of a single record with the number of traces equal to
the number of LIs in the survey and the number of sam-
ples in each trace equal to the number of DIs. A good
way to generate this from a Landmark horizon file is to
first run tim2hed3d in -QCUSP mode (which will only
produce an output on the -F[] disk file but will not
stream any data). Once the usp format horizon record
has been generated it can then be smoothed with
fkkstrip or generally processed. It wll then be ready
for use in tim2hed3d (but not in -QCUSP mode).
-FT Enter the command line argument '-FT' to fit surface to
the input time matrix.
-ord ord
Enter user specified order of the surface to be fit.
The default is to compute the statistically best fit to
the input times. This runs a lot longer and gives a
very good fit but the user is cautioned that "best"
here is a statistical measure.
-iter iter
Enter number of iterations for fit. Default = 5
-ityp ityp
Enter type of fit flag: 1 = robust fit; 0 = least
squares. The robust fit will tend to ignore sharp local
excursions in the input time surface, pushing the fit-
ted surface through it to follow the general regional
trend; the least squares fit will tend to honor smaller
features of the input matrix.
-SM Enter the command line argument '-SM' to do median
smoothing of time matrix.
-QC Enter the command line argument '-QC' to output the
before (and after if fitting or smoothing is done) time
matrix. The default file name will be TIMHED. This can
be displayed using program plotxy. The program will
stop after this file has been generated. It is recom-
mended that the usp format option be used since it is
10x more efficient storing the times matrix.
-QCUSP
Enter the command line argument '-QCUSP' to output the
before (and after if fitting or smoothing is done) time
matrix in usp format. The number of samples per trace
will be equal to the NDI or number of DIs in the time
matrix (between dimin and dimax); the number of samples
wil be equal to NLI or the numbver of LIs in the matrix
(between limin and limax). If the smooth or fit options
are chosen there will be two records in the usp dat a
set, otherwise there will be one record. If no file
name is given the file will be called TIMHED.usp. This
can be displayed using program xsd or xmplot. The pro-
gram will stop after this file has been generated.
-F ftap
Enter file name for -QCUSP option. Default = TIMHED
-DF Enter the command line argument '-DF' to output the
difference between the input times and either the fit-
ted or smoothed surface.
-nf nf
Enter length of one side of the nf x nf median filter.
Default = none
-I Enter the command line argument '-I' to turn off the
interpolator/extrapolator. The default is to interpo-
late holes (zeros) present in the event file.
-E Enter the command line argument '-E' to fill interior
holes in the event file and extrapolate out to the
edges of the survey boundaries.
-f2m Enter the command line argument '-f2m' to scale the
workstation event XYs from feet to meters. The default
is no scaling.
-m2f Enter the command line argument '-m2f' to scale the
workstation event XYs from meters to feet. The default
is no scaling.
-V Enter the command line argument '-V' to get additional
printout.
-? Enter the command line argument '-?' to get online
help. The program terminates after the help screen is
printed.
BUGS
Currently only the 5-column Landmark format is handled. But
awk can be used with most other files to jury rig an accept-
able format.
EXAMPLE 1
tim2hed3d -Nindata -Pevent -Ooutdata -x13000 -y12000 -x20 \
-y23000 -y30 -x43000 -y40 -ildm50 -cldm100 -f2m
where the the X-axis corresponds to the receiver lines and
we go counter clockwise starting from the upper right
(northeast) corner along a receiver line. The workstation
XYs are scaled from feet to meters.
EXAMPLE 2
tim2hed3d -Nindata -Pevent -Ooutdata -x13000 -y12000 -x20 \
-y23000 -y30 -x43000 -y40 -ildm50 -cldm100 \
-FT -ord10 -QC
where we are fitting a 10th order robust surface to the
input times and QC'ing the results. The program will stop
after the surface fit is done.
EXAMPLE 3
tim2hed3d -Nindata -Pevent -Ooutdata -limin20 -limax2000 \
-dimin1 -dimax3000 -lidel10 -didel5 -RC -stk -E
where we are using the line and trace numbers as our coordi-
nate system. Also we have specified that the event file be
extrapolated to the survey edges if the even has zeros sur-
rounding it.
EXAMPLE 4
tim2hed3d -Nindata -Pevent -Ooutdata -limin20 -limax2000 \
-dimin1 -dimax3000 -lidel10 -didel5 -RC -stk -I
same as EXAMPLE 3 but now we have turned off all interpola-
tion and extrapolation.
SEE ALSO
rest
AUTHOR
Paul Gutowski (socon 422) 3146
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