ARMA

NAME
SYNOPSIS
DESCRIPTION
SEE ALSO
BUGS
COPYRIGHT
AUTHOR

NAME

arma - subroutine to apply ARMA filter.

SYNOPSIS

call arma(npts,s1,s2,itype,fcenter,bwidth,npoles,fsamin,ifaz)

DESCRIPTION

Basic Seismic Utilities (BSU) subroutine which applies an autoregressive moving average (ARMA) filter. The filter can be Low | Band | High pass, depending on the itype argument. The filter can also be made zero phase by the usual time reverasal trick specified by argument ifaz. Each filter type is given as an inline subroutine within the arma subroutine. Note: This is a simple filter whose order is achieved by cascading itself recursively (all poles and zeros in same place, easy to code). Filter is designed by Bilinear Transform Method.
Fortran Version
.

Arguments
npts (int)

Number of samples in a trace

s1 (float)

Input seismic trace with data to be filtered, float array. WARNING: This array is changed.

s2 (float)

Output seismic trace with final filtered data. float array.

itype (int)

Selects filter type: 0=Low-Pass, 1=Band-Pass, 2=High-Pass filter.

fcenter (float)

Center frequency in Hz.

bwidth (float)

Bandwidth (Hz), only used if band-pass, itype=1 selected.

npoles (int)

Number of poles in filter. Number of times filter is applied=npoles/2.

fsamin (float)

Sample interval in seconds.

ifaz (int)

Selects phase of filter. 1=minimum phase 0=zero phase.

SEE ALSO

bfil(1), bamp(1), bvas(1)

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>