NAME
anmo3d - apply/remove normal moveout correction to 3D data
SYNOPSIS
anmo3d [ -Nntap ] [ -Ootap ] [ -vvmod ] [ -nsns ] [ -nene ]
[ -rsirs ] [ -reire ] [ -tlenpad ] [ -sscl ] [ -S ] [ -R ] [
-T ] [ -B ] [ -L ] [ -XY ] ] [ -x1x1 ] [ -y1y1 ] [ -x2x2 ] [
-y2y2 ] [ -x3x3 ] [ -y3y3 ] [ -x4x4 ] [ -y4y4 ] [ -cldmcldm
] [ -ildmildm ] ] [ -f2m ] [ -m2f ] [ -shot ] [ -rcvr ] [
-cdp ] [ -V ] [ -? ]
DESCRIPTION
anmo3d takes a set of traces, applies the dynamic correction
and shifts the traces by the calculated moveout time. No
stretch mute is applied for reasons of speed but this can be
simulated by piping the output into a filter program that
lo-cut filters the data (e.g. 'sctvf -f12 -f27', etc).
Alternatively, one may choose to mute the data in the
moveout domain using program mute. Care has been taken to
preserve data pushed up beyond t=0 by optionally using front
padding of the input traces. anmo3d currently uses an accu-
rate 8 point fixed distance interpolator based on bdnmo. The
fixed distance interpolator provides significant improve-
ments in speed with only minimum effects on accuracy in the
reverse transform.
This is somewhat slower than using the regular NMO programs
(see bdnmo or anmo) which read a trace gather from the data
input then read a velocity trace from the volume. These pro-
grams assume that the order of the input data gathers are
locked in sync with the order of traces in the velocity
volume, e.i. read a gather then read a velocity trace.
Traces going into anmo3d can be in any order even random as
long as the velocity volume is built so that each velocity
trace corresponds to a cell in the survey.
Two modes are available: default mode is to read the LI and
DI number of each trace as it is encountered and use these
numbers to look into the velocity volume and extract the
velocity trace corresponding to the appropriate cell; the XY
mode requires the user to define the XY limits of the survey
box and the cell dimensions, then as exch trace is read the
specified XY cooredinates are used to locate the LI and DI
of the corresponding cell. In either case it does not matter
what the numbering of the velocity volume uses only that the
volume have a total number of traces equal to the total
number of cells in the survey box. If LI/Di numbers are not
in the trace header ptogram li_di can be used to insert
them. The user will be required to specify the XY limits of
the survey and the cell dimensions.
anmo3d gets processing controls from the command line. Rea-
sonable defaults are setup. In addition, if no input file
name is given, the binary trace data are expected to be on
the standard input. A velocity model must be specified as a
2D grid where LI corresponds to record number; DI
corresponds to trace number. Consequently, when a trace
with (LI,DI) = (10,12) is read, anmo3d uses record 10, trace
12 of the velocity model as the velocity trace. To compute
a velocity trace at each LI,DI grid point, use program VI3D.
Command line arguments
-N ntap
Enter the full path of the file containing the data
set. If not specified, input is expected to be stan-
dard input. If standard input is not specified and
there is no input, e.g., program run in background,
expect a termination. (default standard input )
-O otap
Enter the full path of the output file. If not speci-
fied, output is expected to be standard output.
(default standard output )
-v vmod
Enter the full path of the file containing the velocity
model. This file is in USP format and is RMS velocity
versus two way travel time. Program will stop if the
velocity model file is not given. The velocity model
must have the same sample interval and number of sam-
ples as the trace data. There must be one velocity-
time trace, for each (LI,DI) coordinate. Program vi3d
(for interpolated 3D velocity functions) is used to
generate the velocity file in USP format.
-ns ns
First trace in record to process (default = 1 )
-ne ne
Last trace in record to process (default = all )
-rs irs
First record to process (default = 1 )
-re ire
Last record to process (default = all )
-t lenpad
Enter time (ms) to pad front of trace. This avoids
truncating (muting) the record at the lowest velocity
after reverse moveout (default = no pad).
-s scl
Enter velocity scaler. Each velocity trace will be
scaled by this factor. Default = 1.0
-S If present apply internal trace header statics (before
nmo).
-R If present remove normal moveout correction
-T If present form the reverse moveout from the top down
(this is the default)
-B If present form the reverse moveout from the bottom up
(default is top down -T)
-L If present perform linear moveout (default is hyper-
bolic moveout).
-XY If present use the XY coordinates of the traces to
locate the appropriate velocity trace; otherwise use
the trace LI/DI numbers.
-shot
Enter the command line argument '-shot' to use trace
source XYs
-rcvr
Enter the command line argument '-rcvr' to use trace
receiver XYs
-cdp Enter the command line argument '-cdp' to use trace
midpoint XYs
-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.
x4, y4]
-x1, -y1, -x2, -y2, -x3, -y3, -x4, -
y4 [x1, y1, x2, y2, x3, y3,
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. If a trace
with an XY lies outside this box an error message will
shut down the program. The user must then decide on how
to deal with such traces, e.g. use li_di to filter them
out.
-cldm cldm
Enter the crossline (along X or side 2-3) cell dimen-
sion (ft,m). For most shooting geometries this will be
1/2 the line or group spacing depending on the orienta-
tion 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 coordi-
nate 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.
-V Verbose mode. List command line and lineheader input
parameters.
-? Query mode. With this flag, anmo3d will give a
description of the command line arguments and stop the
program.
NOTE 1:
The -L option allows one to apply a time and space variant
linear moveout with offset allowing one to apply flows like
anmo3d -L | fkstrip | anmo3d -L -R when the constant velo-
city reduction provided by vred or record invariant dip
filtering provided by dipf are inadequate.
BUGS:
none know at present.
SEE ALSO
vi3d, mute, li_di
AUTHOR
D. E. Wagner using anmo by K. J. Marfurt as kernel; APR
(1993).
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
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