Example Rayleigh Wave Processing: Automated Inversion (invR1.m)

The program, invR1.m, will attempt to determine a layered model which matches a measured phase velocity dispersion profile. As in program, FwdR1.m, the dispersion curve is read from a text file, bvax.his. The Fortran subroutine, rwv.f, must also be in the directory. The inversion ran for 3 iterations. The solution is shown graphically in Figure 47. Only 3 singular values were used (see Figure 48).

Figure 47: Automated modeling with invR1.m. Initial model and intermediate models are shown in cyan. The 3rd, terminating iteration, is shown in red. The fit can be compared to that achieved in Figure 46. The model is shown for the 3rd iteration and is tabulated in the caption of (B). Note that both velocity and depth of control points were free to vary.

Figure 48: Automated modeling with invR1.m. (A) Dispersion as a function of wavelength. (B) Singular values sorted by size. Only the 3 largest singular values were used (P=3).