The computation of travel times of seismic waves, i.e. the time the waves need to travel from the earthquake hypocenter to any given point on the surface, is an important prerequisite for the evaluation of seismograms. To allow drawing conclusions about the interior structure of the planet, different paths must be considered. Reflections at the planetary core, for example, are of utmost importance.
The TTBox software, written in the MatLab language, solves this for spherically symmetrical planetary models, i.e. models in which the propagation velocity of seismic waves depends on depth only. All relevant information on the planet is contained in a single model file. A change of a single input variable is thus sufficient to switch from one planet to another.
The equations used are valid for the infinite frequency limit, in which Snell’s law can be used to compute ray paths. The Flat Earth Approximation is used to transform the spherical problem into a Cartesian one.
TTBox was tested successfully against other software and special cases that can be solved analytically, and results published in a scientific paper (Knapmeyer, 2005).
The software package contains a HTML documentation with tutorial and technical documentation. The first version was released in 2004 (Knapmeyer, 2004), the software was continuously improved ever since.
Contact: Dr. Martin Knapmeyer