Task: Generate Set of Travel Time Curves
To generate and plot a set of travel time curves for a model,
do the following:
- read the velocity model from an .nd file using model=mkreadnd(pfad);
- call ttc=mkttcurves(model,h,dangle); or
ttc=mkttcurves(model,h,dangle,phases); where
- model
- a model structure containing the velocity model
- h
- the focal depth in km for which the travel time curves will be computed
- dangle
- the take off angle resolution (in degrees). Rays will be shot from
the source at angles dangle:dangle:90, measured against the vertical
- phases
- a string matrix giving a list of phases, for which travel time curves
will be computed. Generate this matrix using strvcat.
If phases is not specified, a standard catalogue will be used.
You can also call ttc=mkttquick(model,h,rayparm,dangle); with the
ray parameter as additional input parameter. MKTTQUICK allows to use the output of MKSHOOTRAY as
input and thus to use lists of specific ray parameters / take off angles which produce rays
that arrive at predefined distances.
- The routine will return a variable ttc which is a ttcurve structure.
See section on data structures for details.
- Call mkplotttcurve(ttc,linespec); without output parameter
to plot the travel time curves (the routine will not produce any plot when called with
output parameter).
Here, ttc is the ttcurve structure computed before and linespec is a MatLab linespec string.
MKPLOTTTCURVES plots into the current axis without clearing it ("hold" is on during plot).
When producing plots, the routine sets the "tag" property of line objects to allow later identification.
The used tags consist of the word "phase", a space character, and the respective phase name.
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PREM travel times for P, S, PKP, SKS, PcP, ScS computed with
MKTTCURVES for h=0km and dangle=0.1°. Since MKPLOTTTCURVES tries not to destroy an existing
graph (may be a waveform section), this is not beautified. X axis is epicentral distance in degrees,
Y axis is travel time in seconds. |
You can also call MKTTCURVES without output argument. It will then produce colorful
plots of travel time curves, as well as ray turning point depth, travel time and
epicentral distance as function of ray parameter.
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PREM travel time curves for various phases, focal depth 0km. Such a plot is generated
by MKTTCURVES automatically when called without output parameter.
(same as PDF) |
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The depth to ray turning or reflection point, as function of epicentral distance for various phases,
focal depth 0km. Colors in the plot correspond to the travel time curve plot.
Such a plot is generated
by MKTTCURVES automatically when called without output parameter.
Such plots can also be generated using the MKDEPTHBYDIST routine. |
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Travel Time and Epicentral Distance as function of ray parameter for various phases, focal
depth 0km. Colors in the plot correspond to the travel time curve plot above. Such a plot is generated
by MKTTCURVES automatically when called without output parameter. |
|
Tau(p) curve for various phases, focal
depth 0km. Colors in the plot correspond to the travel time curve plot above. Such a plot is generated
by MKTTCURVES automatically when called without output parameter. |
eof.