Difference between revisions of "Gpsh"
Jump to navigation
Jump to search
| (One intermediate revision by the same user not shown) | |||
| Line 10: | Line 10: | ||
The output is the Fourier transfer function for VERTICALLY INCIDENT plane S waves | The output is the Fourier transfer function for VERTICALLY INCIDENT plane S waves | ||
| − | The computation is based on the reflectivity method | + | The computation is based on the reflectivity method (<ref> Kennett, B. L. and N. J. Kerry (1979). Seismic waves in stratified half space, |
| + | Geophys. J. R. Astron. Soc. 57, 557-583.</ref>), as implemented in (<ref>Bard, P.-Y., & J.-C. Gariel, 1986. The seismic response of two-dimensional sedimentary deposits with large vertical velocity gradients. Bull. seism. Soc. Am., 76, 343-366 </ref>, <ref> Theodulidis, N., P.-Y. Bard, R.J Archuleta and M. Bouchon, 1996. Horizontal to vertical spectral ratio and geological conditions: the case of Garner Valley downhole array in Southern California, Bull. seism. Soc. Am., 86, 306-319.</ref>) | ||
Format for layered models: | Format for layered models: | ||
Latest revision as of 17:53, 9 March 2010
Synopsis
gpsh [OPTIONS] [FILE]
Description
Computes the SH transfer function for layered models given through stdin or FILE.
The input is the soil column defined as listed below. The output is the Fourier transfer function for VERTICALLY INCIDENT plane S waves
The computation is based on the reflectivity method ([1]), as implemented in ([2], [3])
Format for layered models:
Line 1 : <number of layers n including half-space for first model> Line 2 : <thickness (m)> <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>] .... Line n+1 : 0 <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>] Line n+2 : <number of layers m including half-space for a second model - if wished> Line n+3 : <thickness (m)> <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>] .... Line n+m+2 : 0 <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>] Line n+m+3 : <number of layers l including half-space for a third model - if wished> ....
Quality factors are mandatory. Any number of models can be given as input.
Output
The output is the modulus of the transfer function, over the specified frequency range and with the specified frequency sampling. It is corrected for the free surface effect (i.e., divided by 2)
Gpsh options
- -n <count> Number of frequency samples (default=100)
- -max <max> Maximum frequency up to which the transfer function s to be computed (default=20 Hz)
- -angle <angle> Incidence angle (default=90, vertical incidence)
Generic options:
- -help <SECTION> Show help about options. SECTION may be empty or:
all, examples, generic, gpsh
- -version Show version information
- -app-version Show short version information
- -reportbug Start bug report dialog, information about bug is
passed through stdin. This option is used
internally to report bugs if option -nobugreport is
not specified.
- -reportint Start bug report dialog, information about
interruption is passed through stdin. This option
is used internally to report interruptions if
option -nobugreport is not specified.
- -nobugreport Do not generate bug report in case of error
Examples
gpsh < test.model
Calculates SH transfer function from 0.2 Hz to 20 Hz for model 'test.model'.
gpsh < test.model | figue -c
Calculates the same function and plot it.
gpsh < test.model | figue -c -m sh.mkup
Shows the same function on a log-log plot. 'sh.mkup' is a tar.gz file containing an xml description of the graphic format, it can be generated from figue's interface.
Copyright
Copyright (c) 2002-2008 Marc Wathelet. All rights reserved.
See http://www.geopsy.org for more information.
- ↑ Kennett, B. L. and N. J. Kerry (1979). Seismic waves in stratified half space, Geophys. J. R. Astron. Soc. 57, 557-583.
- ↑ Bard, P.-Y., & J.-C. Gariel, 1986. The seismic response of two-dimensional sedimentary deposits with large vertical velocity gradients. Bull. seism. Soc. Am., 76, 343-366
- ↑ Theodulidis, N., P.-Y. Bard, R.J Archuleta and M. Bouchon, 1996. Horizontal to vertical spectral ratio and geological conditions: the case of Garner Valley downhole array in Southern California, Bull. seism. Soc. Am., 86, 306-319.
