bnos

NAME
SYNOPSIS
DESCRIPTION
FILES
SEE ALSO
BUGS
COPYRIGHT
AUTHOR

NAME

bnos - BSU program generates band-limited random noise (random phase)

SYNOPSIS

bnos [ -h | infile | seed | F_Low | F_High | F_Roll ]

DESCRIPTION

Basic Seismic Utilities (BSU) uses the number of traces, sample interval, and geometry from the input file to design an output file of band-limited random noise traces. The random number sequence generates a random phase function in the frequency domain that is combined with a flat amplitude spectrum in the pass-band. The inverse Fourier Transform (radix 2) returns the time domain noise signal. Because the FFT is radix 2, a trace with non-power-of-two samples will be truncated in the time domain. The resulting spectrum of a single truncated trace may not appear flat due to the limited statistics. However, if one averages the autocorrelations of all the traces in a profile, and examines the spectrum of that average auto-correlation, one should observe a fairly flat spectrum between the limits F_Low and F_High. Fortran 77, uses CMLIB routines rand.f and runif.f to generate the random number sequence.

Options

-h

Online help giving details on command line arguments

infile

Input file name used to design the output file headers and traces.

seed

Seed for the random number generator. Floating point positive number less than one.

F_Low

Low frequency limit (Hz) of desired random noise spectrum.

F_High High frequency limit (Hz) of desired random noise spectrum.

F_Roll

Roll-off in Hz. The spectrum will be defined with raised cosine tapers that go from unity amplitude to zero amplitude in F_Roll Hz.

NOTE:
If invoked with no options, will prompt user for input parameters.

EXAMPLE:
bnos wave.seg .9182364826 20. 100. 10.

Noise traces will be generated which match the geometry, sample interval, number of samples , and the number of traces in file wave.seg. The noise will have a pass-band from 20 to 100 Hz, with 10 Hz roll-off.

FILES

bnosxxxx.seg

Output, data set. Named according to convention (first 4char bnos, the next 4char are the first 4char of the input file name, suffix .seg)

standard output

produces a progress bar

bnosxxxx.lst

echo check of input parameters

SEE ALSO

bhelp(1), bnoise(3), rand(3), runif(3), nlogn(3)

BUGS

No known bugs.

COPYRIGHT

Copyright © 2024 by Paul Michaels

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

AUTHOR

P. Michaels, PE. <paulmichaels@.boisestate.edu>