Design And Optimization Of Atmospheric Rayleigh-brillouin Scattering Calibration Chamber

Atmospheric temperature is an important meteorological parameter reflecting the state of the atmosphere.It has a very important guiding significance for weather forecast,environmental protection,atmospheric science and so on.So the measurement of atmospheric temperature is becoming more and more extensive.At present,the measurement methods of atmospheric temperature mainly include sounding balloons,rockets,microwave radiometers,and laser radars.Light detection and ranging(Lidar)has attracted more and more attention due to its high temporal and spatial resolution,wide range of detection,high accuracy and good real-time performance.In the HSRL,the accuracy of temperature measurement is not high because the Brillouin scattering effect is not considered.It provides technical guarantee for improving the accuracy of temperature measurement by Rayleigh scattering and Brillouin scattering in future decoupling atmospheric echo signals.Based on the preliminary theoretical research of the project group and the finite element analysis method,the design and optimization of the calibration box for the calibration of the atmospheric RBS calibration are carried out.The design and construction of the control system for discrete control of temperature and pressure of the fixed box is completed.The FPE is used as the spectroscopic device to test the performance of the calibration box.The main work and research results of this paper are as follows:The finite element analysis method is used to complete the structural design of the calibration box and optimize it.The temperature and pressure of the calibration box are analyzed by finite element method,and the temperature distribution of different time,different power and different materials,and the stress and strain at different atmospheric pressure are obtained.According to the analysis results,based on the negative feedback control theory and the programmable loop regulator,the temperature and pressure discrete control system of the calibration box is designedCombined with the design of calibration box temperature and pressure control system and the corresponding control accuracy,the selection and construction of related devices in calibration box control system were completed.The temperature control precision of the temperature control system was ± 0.03 ? measured by the experiment.The control system was optimized by adding a panel ball valve to the pressure control system.The pressure control precision of the calibrated box was ±5KPa after the optimization.Finally,based on the HSRL,which is studied by the project group,the measurement of the gas scattering spectrum in the calibration box under different temperatures and different pressures is used to test the performance of the calibration box.Based on FPE,the calibration box performance test light-path is built,and the seed line is scanned by changing seed injection.The photon counting system is used to detect weak optical signals.