Design And Implementation Of Meteor Radar Receiver And Data Processing System

Radar technology has been used for meteor observations for more than 80 years.The earliest observations were mainly used in astronomical research,such as meteor showers and meteoroid velocity estimation,and later used in atmospheric observations to study the atmospheric dynamics of the mesosphere and lower thermosphere(MLT)by measuring the radial drift velocity and decay time in the meteor trail diffusion.At present,foreign meteor radar technology is very mature,such as Australia’s all-sky interferometric meteor radar,and domestic meteor radar research is still in its infancy.According to the requirements of meteor detection,this paper designs and completes the meteor radar receiver and data analysis and processing system by using multi-channel radar receiver technology and array antenna technology.The main work of the thesis is as follows:1.The sensitivity of meteor radar is analyzed by the detection parameters of meteor radar,the ideal scattering equation of detecting antenna and meteor echo,and the technical specifications of the receiver are designed.Based on the structure of digital intermediate frequency receiver,the meteor radar receiver is designed and completed.The receiver includes analog receiving front-end circuit,analog-to-digital converter(ADC),digital down-conversion(DDC)and data transmission;the simulation front-end test and closed-loop experimental results verify the correctness of the design,and the technical indicators meet the design requirements.2.The characteristics of Fresnel diffraction process,ideal meteor echo and actual meteor echo are studied.The preliminary selection criteria of meteor echo are established by simulating the attenuation coefficient,pulse repetition frequency(PRF)and signal-to-noise ratio(SNR)of meteor echo.And these criteria are used to select meteor echoes and achieve good results.3.An algorithm for extracting meteor parameters(velocity,angle of arrival,height,diffusion coefficient,radial drift velocity,etc.)from meteor echoes(amplitude,phase)is implemented,and the wind field is derived based on these parameters;The channel phase difference calibration is performed on the receiver based on the angle of arrival and height information of the meteor echo.Finally,the data processing system of meteor radar was designed and completed.For the processing and analysis of the data obtained by the receiver in the actual detection experiment,the meteoroid velocity map,the full sky map,the height distribution map,the diffusion coefficient map and the wind vector map are obtained.Meteor detection experimental and data processing results verify the correctness and feasibility of the meteor radar receiver and data processing methods.