Department of Physics and Astronomy, Washington State University, Pullman, Washington 99163, USA
JASA Express Lett. 2022 Nov;2(11):114001. doi: 10.1121/10.0015069.
Backscattering by metal shells in water was investigated by Morse, Marston, and Kaduchak [J. Acoust Soc. Am. 103(2), 785-794 (1998)]. The evolution of the backscattering as a function of frequency and tilt angle, the "acoustic color," depended on the shell's thickness. The present study concerns scattering by a shell with an intermediate thickness-to-radius ratio (0.106). The results include: (a) meridional rays associated with a supersonic antisymmetric guided wave cause a prominent tilt-angle dependent enhancement at frequencies above the coincidence frequency; (b) a subsonic guided wave is also prominent over a range of frequencies and tilt angles; and (c) meridional ray contributions are evident in the time-frequency-angle domain.
Morse、Marston 和 Kaduchak [J. Acoust Soc. Am. 103(2), 785-794 (1998)]研究了水中金属壳的背向散射。背向散射随频率和倾斜角（“声颜色”）的演变取决于壳的厚度。本研究关注具有中等厚度-半径比（0.106）的壳的散射。结果包括：(a) 与超音速反对称导波相关的子午射线在高于吻合频率的频率处引起显著的倾斜角相关增强；(b) 亚音速导波在一定频率和倾斜角范围内也很显著；(c) 子午射线的贡献在时频角域中是明显的。
