Calibration Method And Experimental Study Of Hyperspectral Lidar Air Temperature Detection System

Air temperature is a very important meteorological parameter in the study of meteorological problems.The accurate measurement of air temperature is of far-reaching significance for studying the global greenhouse effect,climate research,and military meteorological prediction.In order to overcome the problem that the commonly used air temperature measurement methods are easily affected by ground radiation and solar radiation,a method of scanning the scattering spectrum by lidar is used to achieve the inversion of air temperature.Based on the F-P scanning interferometer's hyperspectral lidar temperature detection system built in the previous stage,this thesis completed the hyperspectral lidar temperature measurement system parameter calibration experiment and indoor fixed-point temperature detection experiment.Firstly,a small continuous laser with an output wavelength of 532nm is used as a light source to complete the performance parameter calibration experiment of the F-P scanning interferometer.By optimizing the optical path and changing the incident angle of the F-P scanning interferometer,the full-width half-height(FWHM)of the F-P scanning interferometer was calibrated.The experiment also calibrates the free spectral range(FSR)of the FP scanning interferometer and the amplitude of the driving voltage amplitude of the scanning interferometer when the scanning range is one FSR,to ensure that the interferometer can effectively scan the Rayleigh-Brillouin scattering spectrum signal.Then,through theoretical calculations,when the temperature changes by 1?,the transmission line of the FP scanning interferometer will drift by about 2.1 GHz.In order to further reduce the influence of temperature on the performance of the FP scanning interferometer,this article builds the previous stage The temperature control system has been properly optimized,and the host computer software is used to monitor the temperature control system data in real time.The results show that its temperature control performance has been significantly improved.Then through the temperature control system of the F-P scanning interferometer,it is verified that the transmission line of the F-P scanning interferometer will drift around 2.11GHz when the temperature changes by 1?,which is consistent with the theoretical value.In this thesis,the scattering cell calibration experiment was also carried out.The Nd;YAG solid pulse laser(355nm)was spectrally scanned through the experiment to obtain the proportion of the laser energy at different frequencies,which provided support for the processing of the later Mie signal.The scanning scattering spectroscopy experiment under the condition of constant pressure and temperature change of the scattering cell is completed.By comparing with the actual temperature data,the system error correction is completed.Finally,under the premise of fixed air pressure,according to different temperature conditions in the laboratory,the laser Rayleigh-Brillouin side scattering spectrum signal at a fixed point in the room is scanned,and the temperature data inversion is completed.The inversion results and TentiS6 The model data matches well.