基于广义惠更斯-菲涅耳原理和粗糙面散射理论，考虑发射机到目标和目标到接收机双程路径中大气湍流对光束传输的影响，研究了脉冲波束经漫射目标散射后的二阶统计特性。推导了接收机处双点双频互相干函数(MCF)的表达式，计算得到平均强度以及复相干度因子，并对此进行数值模拟。结果表明，相位结构函数占优情况下，接收面的脉冲平均强度与大气湍流水平无关；但脉冲相干带宽与湍流强度、中心频率、湍流外尺度、观察处两点间距离、频差有关。

Based on the generalized Huygens-Fresnel principle and the rough surface scattering theory, the effect of atmospheric turbulence on both pulse beam propagating to the target and scattering field propagating back to the receiver is studied, and the second-order statistical properties of pulses scattered by diffuse targets are investigated. An expression is deduced for the multiple-frequency mutual coherence function (MCF) of a reflected pulse beam from the rough target in atmospheric turbulence. According to MCF an expression of the mean intensity and the degree of complex coherence at the receiver is derived. The numerical simulation results indicate that the mean intensity is independent on the atmospheric turbulence, and the coherence bandwidth depends on the turbulence strength, the central angular frequency, the outer scale of turbulence, the position separation and the angular frequency difference when the phase structure function is dominant.