Modeling And Simulation Of Laser Timing Link Channel

Laser timing is a kind of timing technology which transmits time information by laser signal.Its link and channel are very complicated.It is an important content of current timing technology research to establish appropriate channel model.In this paper,the principle and method of timing technology are introduced firstly,then the seawater channel and wave channel are modeled,and finally the link channel is simulated and analyzed.The key parts and innovation points of the research are as follows:(1)Research on seawater channel: According to the distribution of chlorophyll concentration in seawater with seawater depth,this paper established a water stratification model based on MC algorithm;By comparing HG-VSF,TTHG-VSF,FF-VSF and Petzold's average particle scattering phase function,the analytic function of FF-VSF is closer to Petzold's function,and it is determined to be the function model of the scattering Angle in this simulation.By comparing the delay characteristics of the SA method and the MC algorithm in three kinds of waters,it is concluded that the SA method has limited considerations,limited application range and loose assumptions.Then,the MC algorithm is chosen as the mathematical model to study the laser transmission in seawater channel.(2)Research on wave channel: theoretical derivation and experimental simulation of three-dimensional waves are mainly carried out by using linear superposition method.Based on P-M spectrum and direction distribution function,the EEDM and EFDM of twodimensional waves are analyzed,and then the modeling and simulation of three-dimensional waves are carried out.By comparing the simulation efficiency of the two methods,it is concluded that the EFDM is more suitable for simulating three-dimensional waves.(3)Develop a channel simulation interactive interface based on Matlab.Functions such as photon packet generation,wave simulation and data processing and analysis can be completed by input parameters.The data processing and analysis are completed: the validity of the seawater channel model is verified by calculating the pulse delay values at different transmission distances and comparing them with the real time delay data;Combined with the wave channel,the influence of different parameters on the pulse broadening of the receiving terminal is analyzed.It is found that the increase of wind speed has little effect on the pulse broadening,but with the increase of the receiving radius and the field Angle,the peak of the normalized impulse response shifts to the right,the falling edge becomes slow,the pulse broadening becomes more serious,and the time delay is larger.To sum up,this paper mainly studies the laser timing link channel model,and obtains the validity of the model through theoretical simulation analysis,which has theoretical reference value for the design of laser timing system in the future.