Research On Detection And Recognition Of Real-time Broadband Spectrum Interference Signal

With the rapid development of radio technology,all kinds of radio services have been widely used,and the space electromagnetic environment is becoming more and more complex.Radio astronomy,which relies on astronomical observation of weak radio signals from the universe more than a billion or even tens of billions of light-years away from the earth,has extremely stringent requirements on the electromagnetic environment around the station.Radio telescope as a highly sensitive radio signal receiving equipment,even very weak radio frequency interference will lead to observation failure or inefficiency.Establish the frequency spectrum monitoring system of the electromagnetic environment of the station,control the electromagnetic environment around the station in real time,monitor the changing trend of the electromagnetic environment with time,and analyze the monitoring data scientifically,reasonably and efficiently.it has become the focus and difficulty of electromagnetic environment monitoring to accurately find out the interference signal and its source.The research on the detection and identification methods of interference signals can better analyze the impact of electromagnetic interference on radio astronomical observation,so as to provide a strong basis for electromagnetic interference mitigation and effectively protect the radio environment of radio astronomical stations.According to the long-term measured spectrum of QTT(Qi Tai Radio Telescope)site,the methods of signal detection and recognition are studied.The specific contents are as follows:First of all,the frequency distribution of radio astronomical services,the main sources of site interference and the scheme of interference mitigation are investigated.The spectrum allocation of radio astronomical services is enumerated in detail,and it is found that some active radio services and electronic equipment in stations pose a potential threat to radio astronomical services.In this paper,the radiation characteristics of electromagnetic interference around the site are analyzed,and the main characteristics of some common interference sources are summarized to provide data support for interference search in the site in the future.Through investigation,some methods of interference mitigation are obtained,which can better serve the radio astronomical observation.Secondly,signal-to-noise separation is a basic problem in the field of signal processing.According to the broadband spectrum data monitored by radio astronomical stations,the advantages and disadvantages of existing signal-to-noise separation are studied.By analyzing the characteristics of broadband spectrum signal and noise,a signal extraction method based on broadband spectrum is proposed.this method is simple,practical and accurate,and provides algorithm support for further signal recognition and statistics.Finally,the data tested by the radio wave environment monitoring system at the radio astronomical site need to be analyzed and processed regularly,and the real-time performance is difficult to be guaranteed,and the automatic monitoring system can be replaced by manual.Pattern recognition technology undoubtedly provides us with a solution.This paper introduces the basic concepts of pattern recognition,investigates several pattern recognition methods,and analyzes their advantages and disadvantages,so as to provide support for future research work.