研究了慢纵向运动双散射散斑场的统计性质。 得出纵向运动双散射散斑振幅自相关函数、 强度涨落自相关函数, 并由此得出, 夫朗和费衍射区内的接收平面上任意点上的自相关函数是时间的非平稳随机过程, 而在光轴附近小区域内, 强度涨落自相关函数是时间的平稳随机过程。 相关时间与散射体纵向运动速度成反比, 理论和实验结果相一致。

Statistical characteristics of double scattering speckle field in longitudinal motion is studied in detail. Its autocorrelation function of amplitude and intensity fluctuations are derived. At the receiving plane within the far-field diffraction region, the autocorrelation function of speckle intensity fluctuations is not generally statistically stationary. While, the time-varying speckle intensity variations become statistically stationary in the vicinity of the center of far-field diffraction plane. The velocity of the diffuser is in inverse proportion to the correlation time. The theoretical result is consistent with the experimental result.