中文摘要：

基于激光脉冲粗糙面散射特征,利用积分变换,误差函数和随机变量的统计矩,研究激光脉冲非相干散射和散射场量的强度起伏协方差函数特征.在入射激光波长？=1.06？m条件下,数值计算了不同粗糙面高度起伏均方和相关长度,不同入射角等影响因素下,散射场相干和非相干分量,以及强度起伏协方差函数随散射角和相干带宽频差的变化情况.计算结果表明,在激光脉冲入射下,随机粗糙面的高度均方越小,相关长度越大,即表面越光滑,散射场的相干和非相干分量在入射角镜反射方向出现最大峰值,非相干分量峰值在非入射角镜反射方向上会迅速减小,且非相干分量在量级比相干散射分量上小很多,散射场强度起伏协方差函数的分布趋势随着相干带宽频差的增大逐步减小,镜反射方向和相干带宽频差为零时出现最大峰值.本文所给出的研究结果,深化了粗糙面脉冲散射场量的四阶统计特征,为开展目标激光脉冲散射场量高阶统计特征和激光散斑探测研究奠定基础.

英文摘要：

According to the field characteristics of laser pulse scattering from a random rough surface, laser pulse incoherence scattering characteristics and a covariance function of the scattered intensity fluctuation are investigated numerically using the integral transform, an error function and the statistical moments of random variables. For an incident laser pulse, numerical methods are used to calculate the coherent and incoherent scattering characteristics and the covariance function of the fluctuation in scattering intensity with the coherence bandwidth frequency and scattering angle, considering multiple factors such as the mean of fluctuating heights, the coherence length of a random rough surface, and the incidence angle. Results show that for the incident laser pulse, a smaller mean of the fluctuating height and a longer correlation length correspond to a smoother surface and larger maximum peak values of coherent and incoherent scattering components in the specular direction. The incoherent scattering peak value decreases more rapidly in the non-specular direction, and incoherent scattering components are an order of magnitude smaller than coherent scattering components. The distribution of the covariance function of the scattering field intensity fluctuation gradually reduces with an increase in the coherence bandwidth frequency difference, having a maximum peak value in the specular direction as the coherence bandwidth difference tends to zero. This paper presents innovative results that emphasize the incoherent scattering characteristics and the covariance function of the scattered intensity fluctuation for the further study of the fourth-order moment statistical characteristic of laser pulse scattering from a rough surface. Future works investigate other high-order statistical moments of laser pulse scattering from a rough surface and laser speckle in laser detection applications.