drum - E. A. Robinson’s subroutine to unwrap phase.
call drum(lphz, phz, jfmax)
Basic Seismic
Utilities (BSU) subroutine originally published by Robinson
(1967) which unwraps the phase spectrum. It has been
modified to begin unwrapping from the frequency associated
with the largest amplitude. Unwrapping proceeds from the
peak in two steps, down to zero, and up to the nyquist. This
strategy helps avoid problems encountered in spectral
notches (where phase becomes meaningless). The user must
supply the frequency index where the amplitude spectrum
peaks (jfmax).
Fortran Version.
Arguments
lphz (int)
Number of
samples in signal phz.
phz (float)
Signal with phase spectrum (assumed here that amplitude and phase have been separated into different signal, type real.
jfmax (int)
Index where spectrum peaks (user must provide). Unwrapping starts at this frequency index.
NOTE:
Phase must be in units of radians.
nrad2(3), flist(3), bfxt(1), nlogn(3)
Robinson, E.A.,
1967, "Multichannel Time Series Analysis
with Digital Computer Programs", Holden-Day, 298p.
No known bugs.
Copyright © 1967 by Holden-Day Inc.
Holden-Day Inc., Liquidation Trust, 1259 S.W. 14th Street Boca Raton, FL 33486 Phone: 561.750.9229 Fax: 561.394.6809
This subroutine is included for distribution with Basic Seismic Utilities (BSU) by joint permission of the author, Enders Robinson, and Holden-Day Inc. Liquidation Trust, Frederick H. Murphy, Trustee. Being part of the BSU package, it is governed by the terms of the GPL license, and 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.
E. A. Robinson