Application Of Modern Spectrum Estimation In QJISR Signal Processing

On the way forward in the scientific age,the development of aerospace industry is becoming more and more important.At the same time,more opportunities and challenges have been put forward for space and astronomical research,and higher requirements for the space ionosphere are also put forward.To date,incoherent scatter radars has been used as a detection tool for the ionosphere and proved to be the most effective.China's first incoherent scatter radar was established in Qujing,Yunnan in 2012 under the support of China's "meridional engineering project".It was called Qujing incoherent Scattering Radar(QJISR).QJISR is mainly used for space debris detection and space plasma detection,as well as plays an important role.With the measured data of QJISR,this paper mainly aims to study the processing method of incoherent scattering signal based on alternating code,optimize the filtering and spectral estimation algorithm,improve the estimation of autocorrelation function,so it has great application value and development prospect.Firstly,the basic principle of incoherent scattering was further elaborated on this basis.Signal processing and an inversion for obtaining ionosphere parameters technique are the main contents of incoherent scattering project.The incoherent scatter signal processing algorithm was analyzed in detail based on alternating code modulation,including integer-order and arbitrary fractional-order alternating codes.Secondly,an autocorrelation function estimation algorithm based on data fitting is proposed.In the traditional incoherent scattering radar signal processing algorithm based on alternating code modulation,aiming at the low of the range resolution at the lag0 and the poor accuracy of autocorrelation function,etc.The auto correlation function is proposed to reverse the autocorrelation value at the lag0,and the feasibility of the proposed method is proved by comparison and analysis of the data processing results of the measured echo data.Moreover,combined with the traditional ISR signal processing algorithm,the experimental data processing of incoherent scattering radar was completed in this paper based on the integer and arbitrary fractional order alternating code.In view of the shortcomings of post detection filtering algorithm and the performance of spectral estimation algorithm,the content showed the idea of FIR filter according to window function and modern spectrum estimation algorithm,and the actual measurement data was used for analysis and verification.Finally,aiming at the incoherent scattering signal processing and analyzing its software functional requirements,the software is developed and designed.Using the simulation and measured data to test and analyze the different functional modules of the software.At present,the software system has been installed and operated on-site at the Yunnan Observatory(Qujing)with good stability and reliability.