suwenjunliu/f-j_test

A try for F-J method to get high order dispersion curve

F-J Test

This is the quick test of F-J method.

What is F-J method?

https://doi.org/10.1029/2018JB016595

F-J method is a kind of seismic method for extracting surface wave dispersion.

What are those files used for

1. freq_bessel_trans.m is the matlab program for F-J transform.
2. PhaseShiftOfSW.m is the matlab program for phase shift method to extract surface wave dispersion.
3. seis-1 / seis-2 or other files like that are the synthetic data generated by QSEIS.
4. Uf.dat / Ur.dat or other files like that are the synthetic data generated by H.M Zhang's program.

About synthetic data

There are some paper about F-J method.

• 基于矢量波数变换法_VWTM_的多道Rayleigh波分析方法_杨振涛
• Frequency-Bessel Transform Method for Effective Imaging of Higher-Mode Rayleigh Dispersion Curves From Ambient Seismic Noise Data_Jiannan Wang

We choose four methods to generate the surface wave data. In order to replicate the results of paper above, we choose same model which is presented below.

Methods

• QSEIS
• H.M. Zhang's Code
• SOFI2D
• SPECFEM2D

Model

To do list

0. complete all the description of program and data file
1. check the validity of F-J method
2. find out a reliable surface wave data, whatever synthtic or real, and treat it as benchmark.

The problem I met

1. the speed of calculation is too slow. Nanqiao provide a python version of F-J method program. With the help of scipy, it runs much faster than before.
2. I still do NOT figure out how to conduct the F-J transform. There are much different version of formula, and I am sure that there must be some typo in the paper especially in chinese version.