SAW propagation in multi-layered tissue mimicking materials

There are 9 ".mat" files in this ".zip" file. Among them, 5 files are the results of three two-layer agar phantoms, and the remaining 4 files are the results of one three-layer agar phantom. In each ".mat" file, there are matrix/vectors of the flattened structure image, flattened SAW axial displacement fields, the reconstructed phase velocity dispersion curve and the estimated shear wave velocities of each layer. The phase velocity dispersion curve was reconstructed based on the flattened SAW axial displacement fields through a 2D FFT analysis (described in detail in Zhou's paper "High‐intensity‐focused ultrasound and phase‐sensitive optical coherence tomography for high resolution surface acoustic wave elastography"). The estimated shear wave velocities of each layer were obtained by fitting the reconstructed phase velocity dispersion curve into the proposed WAPV inversion model. 

Here give the descriptions of each variable in each file:

• Str - flattened structure image
• vzStr - vector of axial distance for structure image in the unit of mm
• vxStr - vector of lateral distance for structure image  in the unit of mm
• Thk_top - the thickness of the top layer in the unit of mm
• Phframe - flattened SAW axial displacement field extracted from the sample surface
• vxPhframe - vector of lateral distance for Phframe in the unit of mm
• vtPhframe - vector of time for Phframe in the unit of s
• Freq - vector of frequency in the unit of kHz
• Cr - vector of reconstructed phase velocity dispersion curve 
• Freqfit - vector of the frequency for Crfit in the unit of kHz
• Crfit - vector of phase velocity curve predicted by WAPV inversion model
• Csfit_bottom - estimated shear wave velocity of the bottom layer
• Csfit_top - estimated shear wave velocity of the top layer