非视线紫外光信号传输时间特性的数值模拟

在研究紫外光学非视线通信技术中,需要深入了解由于紫外大气散射效应所带来的各种信号畸变.传统的单次散射近似方法在进行较远距离、复杂天气条件下非视线光传输模拟时误差很大,采用基于Monte Carlo(MC)方法改进算法进行非视线紫外光信号传输的数值模拟,通过随机抽样的方法模拟光子在大气系统中的随机游动,在光子被大气中的粒子散射时计算其进入探测器的概率,模拟大气系统的脉冲响应函数.模拟结果表明:采用光子散射探测概率方法改进后的MC模型在模拟非视线光信号传输时计算效率显著提高;大气系统对非视线传输时的紫外光脉冲具有很强的展宽效应;随着光信号传输距离的增大,信号强度呈近似指数衰减的趋势.

Numerical Simulation of NLOS Ultraviolet Signal Propagation Characteristics

In researching the technology of UV inspection and UV communication, it is necessary to study the signal distortion produced by the UV lighfs scatter effect. The traditional method single-scattering theory brings larger error when it is used for long distance and complicated weather NLOS light propagation situatior. An improved algorithm based on the Monte Carlo simulation of NLOS optical propagation is presented. Photon random walk in the atmosphere system is simulated by random sampling method, the probability of photon that can enter the detector is calculated when it is scattered by the atmospheric particle, and the pulse response function of the atmosphere system is simulated. The calculation result shows that the detection probability method can obviously improve the computational efficiency of the Monte Carlo simulation, the atmosphere system will produce a very strong impulse broading effect to the NLOS optical propagating UV light and the signal decays exponentially with increasing distance of the propagation approximately.