genwav - Interactive program to generate namelist file for input into program waves
genwav
Compatible with Basic Seismic Utilities (BSU), this program genrates the namelist input file for program, waves , which computes Rayleigh wave dispersion curves in an elastic, 1-D layered earth. The program is interactive and prompts the user for an earth model, spectral limits, number of modes, and other signal processing requirements. Fortran 77 Version.
Example
dialog
pm@penguin:~$ genwav
enter name of namelist file (40
char)
Example: waves.d
waves.d
enter name of dispersion curve file
(this is file from disper.f)
Example: earth.crv
earth.crv
enter near offset: xnear
1
enter group interval: delx
1
enter number of receivers: nrec
48
enter minimum group velocity expected
100
RECOMMENDED minimum tmax= 0.9600
enter: maximum trace time, tmax
2.0
enter: sample rate, fsamin
.001
enter frequencies: fmin, fmax
10,100
enter maximum mode to include
9
enter ksw switch 0=c plot, 1=k plot
0
enter type of plot format, mapmat
0=scilab 1=maple
0
enter Output option 0=Vertical 1=Radial
0
enter source depth
0
enter (3) diagonal elements, moment tensor
0,0,1
Padded Radix 2 tmax= 4.0960
Number of points in signal= 4096
--------------------------------------------------
.......Frequency interval= 0.24414061
NOTE: Frequency Interval MUST MATCH DISPER OUTPUT
WAVES will output signal length = 1.0/delf
IF MISMATCHED: CHANGE sample rate in WAVES
or RERUN DISPER
--------------------------------------------------
Number of frequencies= 409
output in =====>waves.d
File waves.d would then be processed by waves .
waves.d (or any other name you choose, first input)
This file will have the namelist content needed for waves .
Example Output
The following is a listing of the waves.d file contents generated by the above dialog.
waves.d
&waves
ksw= 0, stepz=20,
modes=1,2,3,4,5,6,7,8,9,
fmin= 10.0000, fmax= 100.0000,
fsamin= 0.00100,
curve=’earth.crv’,
mapmat=0,
matlb1=’maplec’, scilb1=’matc.sci’,
matlb2=’mapleu’, scilb2=’matu.sci’,
irvsel=0,
ofile=’waves.tmp’, /
&source
tm= 0.0, 0.0, 0.0,
0.0, 0.0, 0.0,
0.0, 0.0, 1.0,
sz= 0.00, sy=0.00, sx=0.00, /
&recvr
nrec=48,
rz=0.0,
ry=0.0,
rx=
1.000, 2.000, 3.000, 4.000, 5.000,
6.000, 7.000, 8.000, 9.000, 10.000,
11.000, 12.000, 13.000, 14.000, 15.000,
16.000, 17.000, 18.000, 19.000, 20.000,
21.000, 22.000, 23.000, 24.000, 25.000,
26.000, 27.000, 28.000, 29.000, 30.000,
31.000, 32.000, 33.000, 34.000, 35.000,
36.000, 37.000, 38.000, 39.000, 40.000,
41.000, 42.000, 43.000, 44.000, 45.000,
46.000, 47.000, 48.000,
/
name of dispersion curve file
This is the output file name from the disper run.
|
xnear |
This is the near offset distance in meters for first geophone. All geophones are placed at depth=0 by default (change rz=0.0 if at depth). | ||
|
delx |
This is the constant geophone spacing in meters. | ||
|
nrec |
This is the number of geophones (receivers) for the synthetic seismogram. An array of rx= values are generated from the above choices for near offset and geophone spacing. |
minimum group velocity expected
This is used to estimate a minimum maximum time to avoid Fourier Transform wrap around. The program then gives an estimate to use.
|
tmax |
The maximum time (in seconds) for synthetic seismogram traces (synthetic seismograms computed by program waves). |
sample rate
This is actually the sample interval in seconds. This establishes the frequency interval consistent with the intended aperture in the case where the wave output will be used to compute synthetic Rayleigh wave seismograms in bsegy format.
frequency minimum and maximum
These are given in Hz. Recommend using more bandwidth than you are interested in. Too little bandwidth will produce a very ringy synthetic seismogram. You can always filter the synthetic back later.
maximum mode #
Phase velocities will be computed for modes 1 through maximum_mode. Hard-wired limit is 9 modes.
ksw switch
This controls type of dispersion plot, by phase velocity or wavenumber.
plot format
This chooses the type of output file for plots, Scilab or Maple.
output option
Choose either Vertical or Horizontal particle motion for output. Output files named wavV.seg or wavR.seg respectively. The variable irvsel=0 chooses vertical component geophones, and irvsel=1 selects radial, in-line horizontal geophones.
source depth
The depth of the simulated source.
3 diagonal elements of moment tensor
For an explosive source, 1,1,1. The elements are t11,t22,t33 (horiz-x,horiz-y,vertical). You can edit the waves.d file to fill in other possible source types, like double couple. For a vertical impact source, 0,0,1 would be entered.
disper(1), gendis(1), waves(1), showmdl(1), halfsp(1)
no known bugs
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.
P. Michaels, PE. <[email protected]>