bzrt - BSU program to solve for PCA on R- and T- components of 3-C surface phone
bzrt [ -h | infile | chV | chH | ipct | hsw1 | tmin | tmax ]
Basic Seismic Utilities (BSU) uses Principal Component Analysis (PCA) to study the vertical particle motion recorded on a 3-component geophone. Intended to study primarily Rayleigh waves, the user is responsible for understanding the source and likely type of wave sensed. One can set a threshold for analysis (ipct), and this can help favor the likely hood of surface waves in the recording, assuming the geophone is on the surface of the ground. A postscript file is created to plot the samples above the threshold RELATIVE to the V-component. There is a 180 degree ambiguity. One must also provide an indication of which component is being used on the horizontal component. This is done with parameter hsw1 which is used to label the horizontal axis on the hodogram plot. File bzrtPCA.lst, contains triplets specifying the time at the center of the window and the two angles resolved by PCA of the major axis of motion relative to the vertical. Multiple runs of bzrt will append results in this file. Code is in Fortran 90.
Options
|
-h |
Online help giving details on command line arguments | ||
|
infile |
Input file name. | ||
|
chV |
Channel number corresponding to V-component | ||
|
chH |
Channel number corresponding to the horizontal component (either R- or T-component). | ||
|
ipct |
Percent of peak motion modulus. To be included in PCA, sample amplitude must be > ipct. | ||
|
hsw1 |
Switch to set label for horizontal axis on the Postscript plot. Examples: |
hsw1=2 Horizontal axis is R-component.
tsw1=3 Horizontal axis is T-component.
You are specifying directions that arrows on phone point, motion in that direction negative volts.
|
tmin |
Start time of analysis window in seconds. |
|||
|
tmax |
End time of analysis window in seconds. |
NOTE:
If invoked with no options, will prompt user for input
parameters.
EXAMPLE:
bzrt 0019.seg 1 2 50 2 8.0 8.5
The input file is 0019.seg, vertical component is channel 1, horizontal component is channel 2. Amplitudes exceeding 50% of the peak amplitude in the window will be included in PCA analysis. The horizontal axis label on the plot is set by hsw1=2 (R-component). The window extends from 8.0 to 8.5 seconds.
XXXX.ps
Postscript plot of PCA. In this example, the file name would be 0019.ps.
bzrtpca.lst
File with triplets (time, angle-1, angle-2) (180 degree ambiguity). File is appended so that multiple runs of bzrt will build up a list of azimuths and amplitude.
bzrtXXXX.lst
This lists the PCA analysis details. Naming convention for example above, XXXX=0019, (ie. bzrt0019.lst). Includes Echo check of input parameters in listing file.
standard output
produces a progress bar
bhelp(1), bhod(1), bazi(1)
no known bugs
Copyright © 2021 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.
P. Michaels, PE. <[email protected]>