Extended Seismic Travel Time Tables
David P. Anderson
dpa@io.isem.smu.edu

This directory contains the extended p-wave seismic travel time table
created by Dr. Ileana Tibuleac for the SMU Linear Event Recognizer.
It is calculated to depths of 2880 kilometers, the core-mantle
boundary, in 10 kilometer steps, and to distances of 98 angular degrees,
in 1 degree steps.  This table was generated by raytracing the standard
earth model (IASPI) and calibrating with published data to 799 kilometers,
and with signals reflected from the core/mantle interface.

The data is in the form of a C "struct" as an array of
99 x 289 floats.  Subroutines are provided for table lookup and
linear interpolation of the table entries in the file "ttime.c"

A command line interface is provided in the file "tt.c" which
takes two arguments, depth in km and angular distance in degrees,
and returns a travel time in seconds. 

Here is a sample tt command and its output:

$ tt 1445 45.6
1450.00 km	45.60 deg	411.07 sec

For depth/distance combinations that are shadowed by the earth's
core, the routine returns "no_data" as the travel time.

This code was compiled with the gnu gcc compiler.

11 Dec 02
dpa