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Program package ANRAY95, version 3.01
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Dirk Gajewski *), Ivan Psencik **)
*) Inst.of Geophysics, University of Hamburg,
Bundesstrasse 55, 20146 Hamburg, FRG
**) Geophysical Institute, Czechosl.Acad.Sci.,
Bocni II, 141 31 Praha 4, Czechoslovakia
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Working version, not yet fully debugged
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Program package ANRAY95 can be used for computation of rays,
travel times, ray amplitudes and ray synthetic seismograms in 3-D
laterally varying structures containing isotropic and/or anisotropic
layers. Synthetic seismograms can be constructed at receivers
distributed regularly or irregularly along surface, interfaces or
vertical profiles.
Program package consists of nine programs, basic program ANRAY
and programs ANRAYPL, SYNTAN, SEISPLOT, POLARPLOT, FRESAN, SYNFAN,
BPLOT and VELPL.
Program ANRAY is an updated version of program with the same
name which has been used in packages ANRAY86 and ANRAY89 written by
Gajewski & Psencik [1],[2]. It is designed for ray, travel time and
ray amplitude computations. Rays can be computed in two modes. In the
first one, rays are specified by the point source location and the
initial orientation of the slowness vector at the source: initial-value
ray tracing. In the second mode, rays are specified by the point source
location and a system of regularly or irregularly distributed receivers
situated on surface or on an interface or on a vertical profile:
two-point ray tracing. The point source can be situated at any point
of the model. Polarization vectors, geometrical spreading and
reflection, transmission and conversion coefficients may be evaluated
along the rays. Program ANRAY can produce three files, one for plotting
ray diagrams, travel times and ray amplitudes, second for computation of
synthetic seismograms and third for plotting plane sections of slowness,
phase velocity or group velocity surfaces. Program ANRAY consists of
32 routines which must be compiled all together.
The program ANRAYPL can be used for plotting of horizontal and
vertical ray diagrams, time-distance and amplitude-distance curves
of individual elementary waves computed in the program ANRAY.
Several types of point sources, namely explosive source, single
force, double couple source can be considered. Program ANRAYPL is
a modification of the program RAYPLOT from the package SEIS83 [4].
Program ANRAYPL consists of 4 routines: ANRAYPL, BORDER, SERV and
SOURCE.
The program SYNTAN can be used for computation of ray synthetic
seismograms from the results computed in the program ANRAY.
Gabor wavelet is used as a source-time function. Hilbert transform
of this wavelet is evaluated by approximate formula, see [3].
Several types of point sources, namely explosive source, single
force, double couple source, can be considered. Program SYNTAN is
a modification of the program SYNTPL from the program package SEIS83
[2]. Program SYNTAN consists of 3 routines: SYNTAN, SERV and SOURCE.
Programs FRESAN and SYNFAN can be used for frequency domain
computation of ray synthetic seismograms. Frequency response is
computed in the program FRESAN. In the program SYNFAN it is multiplied
by the spectrum of the considered source-time function. Inverse
Fourier transform is then used to evaluate synthetic seismograms.
Programs FRESAN and SYNTAN are modifications of the programs GB
and SYNTGB from the package BEAM87 by V.Cerveny.
Programs SEISPLOT, BPLOT and POLARPLOT can be used for plotting
results computed in progams SYNTAN and SYNFAN. Program SEISPLOT can be
used for plotting synthetic seismograms generated by the program SYNTAN,
program BPLOT can be used for plotting synthetic seismograms generated
by the program SYNFAN. The program POLARPLOT serves for plotting particle
motion diagrams and can be used in both cases. Programs SEISPLOT and
POLARPLOT are modifications of the programs with the same name from
the package SEIS83, program BPLOT is a modification of the program
with the same name from the package BEAM87.
Program VELPLOT can be used for plotting plane sections of
slowness, phase velocity and group velocity surfaces from the file
generated in the program ANRAY. Program VELPLOT consists of two
programs: VELPL and SERV.
FORTRAN77 is used throughout the program package ANRAY89. Standard
CALCOMP routines, namely PLOTS, PLOT, SYMBOL and NUMBER, are used in
plotting programs.
The program package is not fully debugged. Problems can be encountered
especially in regions in which two slowness surfaces of the shear waves
are close to each other. The ray method gives in such regions distorted
results and the two-point ray tracing procedure can fail there. Any
report on errors or inconsistencies, which may be encountered by users
is, therefore, welcome.
In case of publication of results obtained with the program
package ANRAY95, the users are asked kindly to refer to this report.
Good luck!
Hiroshima, March 1995
REFERENCES
[1] Gajewski,D., Psencik,I., 1986. Numerical modelling of seismic
wave fields in 3-D laterally varying layered anisotropic
structures - Program ANRAY86, Internal Report Inst.of Earth and
Planet.Phys., University of Alberta, Edmonton.
[2] Gajewski,D., Psencik,I.,1989. Ray synthetic seismograms in 3-D
laterally inhomogeneous anisotropic structures - Program ANRAY89,
Internal Report Centre for Computational Seismology, LBL,
Berkeley.
[3] Cerveny,V., Molotkov,I.A., Psencik,I.,1977. Ray method in seismology,
Univerzita Karlova, Praha.
[4] Cerveny,V., Psencik,I.,1984. Documentation of earthquake
algorithms. SEIS83 - Numerical modeling of seismic wave fields
in 2-D laterally varying layered structures by the ray method.
E.R.Engdahl, edit., Report SE-35, Boulder, 36-40.