Group velocity dispersion curves estimation based on joint processing of sound pressure and vertical particle velocity

It is difficult to separate and estimate the intersected group velocity dispersion curves for different normal modes when the frequency is lower than the cutoff frequency of water column. To address this issue, an estimation method based on the joint processing of sound pressure (P) and vertical particle velocity (Vz) is proposed in this paper. Theoretical analysis shows that the amplitudes of P and Vz corresponding to the nth normal mode exhibit a complementary relationship in the certain frequency band, providing a theoretical basis for the method. The feasibility of the method was verified using sea trial data.