Design And Implementation Of High Spectral Resolution Lidar System For Near-surface Air Temperature Detection

Air temperature is one of the basic parameters describing atmospheric physical chemistry,weather dynamics,meteorology and environmental research.Changes in air temperature can cause changes in atmospheric physico-chemical,kinetic processes and trace component distribution.Because the radiative forcing factors have great changes on both the horizontal and time scales,the distribution of the air temperature field has a large degree of variability.Hence,it is difficult to be forecasted.Air temperature detection can provide important data for analysis and forecasting of weather,atmospheric environment and atmospheric dynamics processes.Air temperature detection has a great significance for studying solar radiation,explaining the phenomenon of global warming,improving the accuracy of weather forecasting,and especially studying the urban heat island phenomenon.In this thesis,based on the detection method of near-surface air temperature of high spectral resolution laser radar,a near-surface air temperature detection laser radar system is designed,including laser emission system,optical receiving system,spectroscopic system and photoelectric detection system.The collimation beam expanding system of the laser emitting system part and th e optical design of the spectroscopic system and the spectroscopic system and the overall mechanical structure design are completed.According to the near-surface air temperature detection requirements and the overall system structural characteristics,a matched package structure is designed.The temperature and frequency characteristics of the mechanical structure were analyzed by SolidWorks finite element analysisAccording to the designed air temperature high spectral resolution laser radar system,an analog detection system was built in the laboratory to realize the detection of the scattering pool temperature.The voltage control method was designed according to the pulse laser frequency and the parameters of the scanning confocal F-P interferometer and the voltage attenuation circuit was debugged.The scattering pool with adjustable temperature and pressure is used as the detection ob.ject,and the scattering spectrum scatter measurement under different temperatures and pressures is respectively performed,and the measured signal is processed and inverted to obtain the required temperature information.The results show that the temperature and measured temperature error obtained by the experimentally measured Rayleigh scattering scatter spectrum inversion is less than 1.9K,which verifies the feasibility of the system.The analysis shows that the near-surface high spectral resolution Rayleigh temperature-sensing radar can detect the temperature and provide a feasible solution for near-surface air temperature detection.