Research Of 1550nm All-fiber Cohorent Doppler Wind Lidar

With the application of optical fiber in the field of communications,more and more optical communication devices have appeared in our lives,and have also promoted the development of optical fibers in other fields.The wind lidar system has also become all-fibre system as a communication system.Recently,all kinds of all-fiber wind lidar products and researches have been continuously reported.The world has huge wind power,wind power is growing rapidly year by year,and wind lidar systems currently used in wind power generation are extremely expensive,which also limits the number of wind lidar systems used in wind power plants,and therefore studies a kind of cheap all-fiber wind lidar system is of great significance.Not only a large number of wind lidar systems can be used in wind power plants,but at the same time it can increase the utilization of wind energy.This paper focuses on an all-fiber laser wind lidar for measuring a near-range atmospheric wind field of the range from0 to 100 meters.First,the research process of domestic and international Coherent Doppler Lidar is discussed in detail.Through the analysis of the development of CDL at home and abroad,1.55?m CDL is the best choice with value in use.Secondly,this paper introduces the basic detecting theory of Coherent Doppler,including Doppler effect and coherent detecting.Thirdly,this paper introduces the structure of the coherent wind lidar system and the entire system is model-analyzed,through the general theoretical analysis and comparison,the highlights of the project design are revealed,the radial wind speed error can be represented by wind speed variance and the wind lidar system uses photonic crystal laser technology and synchronous frequency modulation technology.By using these three technologies,we can improve signal-to-noise ratio of the system and simplify the system structure and make the system have great practicality.Finally,this paper uses the signal processing method used in this system to measure the simulated Doppler shift,the simulation results indicate that the more noise is added to the signal,the more errors will be obtained from the calculation and the system's coherence is also verified and the optical system's transmittance is tested and the lidar system is utilized to measure the velocity of atmosphere indoor and the absolute errors are less than 0.15m/s.