Acoustic error approximation due to Gouy phase in the sea
Acoustic error approximation due to Gouy phase in the sea
复制标题
海洋中古伊相位引起的声学误差近似
作者：
M. Kobold;P. Beaujean
为了估计相干声系统的水下传播的统计相位，基于波速的背景结构函数的计算提供了排除由于聚焦而产生的相位的波前畸变度量。 1890 年，Gouy 测量了通过焦点的相位变化，球面会聚与柱面会聚的相位变化相差 π/2 的 2 倍。对可能焦点腰位置的统计可以使用基于测量的声速分布的结构函数。相位估计很容易受到相位估计误差的影响，除非结果考虑通过焦点腰时的古伊相位。这些焦点可能会抵消或平均其他估计误差，包括散射、传播类型（圆柱形与球形焦点）以及来自表面和底部的反射。海洋有足够的范围来容纳声速剖面的空间导数，以持续贡献我们所展示的具有相干时间和横截面空间（成像）相干性的焦点。作为替代方案，镜面点理论可以估计确定性压力解。这些违反固定相的射线模型的收敛需要突变理论等方法来估计焦点效应。索末菲早期有一个全面的射线理论描述，其中包括古伊相。使用弗拉特的数据，焦点显然在时间和长度上是一致的。从统计上看，大西洋、加勒比海和墨西哥湾地区的相互相干函数表明，即使是扭曲和异相的会聚也具有完全的空间相干性。
In order to estimate the statistical phase of underwater propagation for coherent acoustic systems, a calculation of background structure functions, based on wavespeeds, provides a wavefront distortion metric that excludes the phase due to focusing. In 1890, Gouy measured a phase change through the focus that differs for spherical vs cylindrical convergence by a factor of 2 from π/2. Statistics for the locations of the probable focus waist can use structure functions based on the measured sound speed profiles. Phase estimates are susceptible to errors in phase estimation unless results consider the Gouy phase while passing through focus waists. These foci may counteract or average with other errors of estimation, including scattering, type of spreading (cylindrical vs spherical foci), and reflections from the surface and bottom. Oceans have a sufficient range for the spatial derivatives of sound speed profiles to contribute persistently to foci that we show have coherence time and cross-sectional spatial (imaging) coherence. As an alternative, specular point theory can estimate deterministic pressure solutions. Convergence of these ray models that violate the stationary phase requires methods such as catastrophe theory to estimate the focal effects. Sommerfeld had an early comprehensive ray theory description that includes the Gouy phase. Using Flatté’s data, the foci are clearly time and length coherent. Statistically, the mutual coherence function for the Atlantic, Caribbean, and Gulf of Mexico regions shows that even distorted and out-of-phase convergence has full spatial coherence.
影响因子：
7
作者：
Lee, Taehwa;Cheong, Yeonjoon;Guo, L. Jay
通讯作者：
Guo, L. Jay