Research On Transient Interference Suppression Algprithm Of Sky-wave Rader

The People's Republic of China,with its vast land and sea areas,is rich in resources and nurtures a variety of lives.Our vast territory,the protection of this blue treasure depends on the booming level of science and technology.Radar is the eye of the coastline,but radar is also subject to a lot of interference when it detects the target.In this paper,the transient interference and the suppression algorithm of the over-the-horizon radar are studied.Firstly,the working principle and system structure of sky wave over-thehorizon radar are studied and studied.It is because of its unique structure and special working mode that it has many advantages that traditional radar does not have.However,due to a lot of external noise and interference in high frequency band,the electromagnetic environment is harsh,and transient interference is one of them.The presence of transient interference will increase the original noise base of the radar,which is generally 20-40 db higher,and may even drown the useful signal and affect the detection performance of the radar.According to the different detection scene of sky wave over-the-horizon radar,the kinds of transient interference are also different.In this paper,the causes and modeling principles of three typical transient interferences are given,and the effects of each on sky wave over-the-horizon radar are analyzed.Then,based on the general process of transient interference,after the detection of transient interference and the setting of zeros to the data,the effective data shall be recovered.The effect of recovery directly affects the suppression effect of the whole interference.Therefore,the data recovery algorithm is studied.Based on the characteristics of sky wave over-the-horizon radar echo signal,the traditional AR method is extended to ARIMA method,and the Exponential Smoothing method is combined.Theoretical and simulation results prove that this combined prediction method can effectively recover data.In the data recovery algorithm,we also study the BPNN algorithm,which is also suitable for the nonlinear data recovery.For the detection and suppression of transient interference,this paper mainly studies time-frequency analysis methods,including CEMD algorithm,AGR and ST method.According to the signal processing in a different way,it is divided into two categories: one is based on the principle of signal decomposition algorithm,such as the CEMD algorithm and the AGR method,the two algorithms can be transient disturbance signal decomposition,and refactoring directly with residual signal,but the study found that the CEMD algorithm in computing efficiency of compromise,actual application data reconstruction effect is not ideal,but transient interference detection is accurate;The second is the ST method.On this basis,the GST algorithm is studied.The algorithm has a high time-frequency resolution and can effectively detect transient interference.