“…4,7,8 The dispersion of waves propagating through materials is typically interpreted in the context of frequency and wavenumber domain information and obtained from discrete spatiotemporal data via discrete Fourier transforms and related methods. [9][10][11][12][13][14] However, such techniques typically only supply real wavenumber information (or their magnitudes) from twodimensional, discrete, spatiotemporal wave propagation information, such as may be obtained from scanned receiver measurements. Several methods have been proposed to characterize wave attenuation and extract complex wavenumber information; [15][16][17][18][19][20][21][22] however, each has restrictions, as: (i) they are usually based on measurements of wave amplitude decrease with respect to time, [15][16][17][18] (ii) they are iterative methods applied in space, like the modified Prony method, 19 (iii) the number of modes has to be known in advance or a unique mode has to be isolated, [15][16][17]20,21,23 (iv) the modes contributing significantly to the signal are presumed to not interact or overlap with one another, or (v) they must include a third dimension of information, such as would be the case in an experiment with a scanned emitter and a receiver.…”