光束在尾流气泡中传输的复散射效应

为了了解光束在尾流气泡中的传输特性，为前向光尾流的探测提供理论依据，研究了光束在尾流中传输时传播方向上和横截面方向上的辐射强度分布特性.基于辐射传输方程的小角度近似解，得到了探测截面上的约化强度和漫射强度的表达式，其中漫射强度表征了复散射的强弱|针对典型的尾流气泡分布，通过数值计算分析了光束传输方向上的约化强度和漫射强度与接收视场角、光学厚度和光束大小的关系，也计算分析了光束横截面方向上的辐射强度随光束大小和横向距离的变化关系.结果表明，光束在尾流气泡中传输时复散射效应明显，且复散射的强弱与接收视场角、光束直径、光学厚度和横向距离密切相关.

Multiple Scattering of Laser Beam Propagating in Ship Wakes

Intensity distributing characters on the axis of Gaussian beam propagating in ship wakes and on the cross-section vertical to the beam axis are investigated to understand the transferring property of laser beam in wakes and to provide the theoretic basis for detecting ship wakes by forward light beam attenuation.Based on the solution of the radiation transfer equation in the narrow angle approximation,the formulations for radiation intensity,which is divided into un-scattered intensity and scattered intensity denoting the extent of multiple scattering,detected by received section are derived.Given a typical bubbles′ distributing function,numerical computations and analysis are given for the un-scattered intensity and scattered intensity on the beam axis relating to detector′s view of field,optical depth,and beam size| similarly the numerical results are also presented for the radiation intensity on the cross-section vertical to the beam axis relating to transverse distance and beam size.The results show that the multiple scattering coming from laser beam propagating in ship wakes is obvious,and the extent of multiple scattering has a close connection with view of field,beam size,optical depth,and transverse distance.