Local high-frequency asymptotics and eikonal equations; problems
with multivalued global solutions of the eikonal equations
(functional space, boundary conditions).
Space-time ray method; space-time eikonal equation; space-time
ray tracing (Hamilton) equations; Hamilton-Jacobi equation.
Time-harmonic ray method; spatial eikonal equation; ray-theory
travel times; spatial ray tracing (Hamilton) equations;
ray coordinates.
First-arrival travel time; minimum Fermat's and Huygens'
principles; minimum ray-theory travel time versus first-arrival
travel time.
Meaning of travel times and material parameters (propagation
velocities) at finite frequencies; problems of attenuation,
scattering, anisotropy.
Efficiency of ray tracing; Lyapunov exponents for ray tracing.
Two-point ray tracing algorithms; ray histories; interpolation
within ray cells, wavefront tracing.
Grid travel-time tracing algorithms.