... O(κ), (51)308 Waves in Fluids and Solids Waves in Fluids and Solids 292 [52] Y. Xu et al, Chin. Phys. Lett. 22, 2557 (2005). [53] Y. C. Chang, L. J. Yeh, and M. C. Chiu, Int. J. Numer. ... rqwhere jn and hnare the n-th order spherical Bessel and Hankel function of the first kind and Pnis a Legendre polynomial.298 Waves in Fluids and Solids Inverse Scattering in the Low-Frequency ... ξ1, ξ2, ̺1, ̺2, ̺3, d and are given in the Appendix of (19).304 Waves in Fluids and Solids Inverse Scattering in the Low-Frequency Region by Using Acoustic Point Sources 150 0.05 0.1 0.15...