SeismicRayTrace.jl

This module is used to calculate travel time between two points in a layerd model.

Usage

using SeismicRayTrace
depth1 = 0.0 # depth of first point
depth2 = 1.0 # depth of another point
distance = 10.0 # horizontal distance
model_depth = [0.0, 1.0, 2.0] # depth of each interface
model_velocity = [1.0, 2.0, 4.0] # velocity under the related interface
phase_type = ["all"] # can be refraction, reflection and guide
travel_time = raytrace(depth1, depth2, distance, model_depth, model_velocity, phase_type)

Return Value

The return values are like:

(x = 4.0, t = 4.0, p = 1.0, l = 0, type = "refraction"),
(x = 3.99999,t = 4.47213,p = 0.8944267450394816,l = 2,type = "reflection"),
...
(x = 4.0, t = 3.7320508075688776, p = 0.5, l = 2, type = "guide")
...

The program first solve the equation to get ray parameter p, and then get the horitonzal distance x and travel time t. l means the layer on which the ray reflect or became guide wave.

Tips

There are artifacts between $\alpha$, $\epsilon$ and MAX_STEP.

• To run faster, set a larger $\alpha$ and/or larger $\epsilon$
• When MAX_STEP triggerd, consider setting smaller $\alpha$
• use internal function SeismicRayTrace.set! to change these parameters