针对激光脉冲在沙尘天气中的时延和展宽问题，以光信号在离散介质中的传输理论为依据，求解了脉冲信号在传播过程中的双频互相关函数，推导了沙尘天气下的脉冲响应。通过分析沙尘天气中不同能见度下激光脉冲时延和展宽的变化情况，得到了激光脉冲的时延量和展宽量与沙尘能见度间的关系，并分别研究了波长为3.8、7.6 和10.6 μm 的激光脉冲的时延和展宽与沙尘天气中大气能见度间的关系。结果表明：在波长一定的情况下，激光脉冲的时延量和展宽量随能见度的增加呈负指数形式减小，并逐渐趋于稳定值。同时，在能见度一定的情况下，激光脉冲的时延量和展宽量会随信号波长的增加而增加。

Based on the theory of optical signal transmitting in discrete medium, the two- frequency mutual coherence function and impulse response are derived for laser pulse delay and broadening problem in sand and dust weather, respectively. The relationship of laser pulse delay and broadening to atmospheric visibility in sand and dust weather is presented. In particular, the time delay and broadening is analyzed when the laser pulse wavelength is 3.8, 7.6 and 10.6 μm. Simulation results show that when using a specific laser wavelength, the laser pulse delay and broadening will decrease in a negative exponent form with the increase of atmospheric visibility and eventually converged to a definite value. Moreover, the laser pulse delay and broadening will increase with the laser wavelength increasement under a certain atmospheric visibility.