Research On Clutter Suppression Filter Design Method Based On Environmental Information

Radar signal processing is a processing method to obtain useful information such as the speed,angle and height of the target of interest by analyzing and processing the radar echo data.Because there will be a lot of strong clutter interference in the received echo data of the radar,this will seriously affect the performance of the radar's detection,positioning,tracking and recognition of the target of interest.In order to reduce the influence of clutter on the radar target detection performance,it is necessary to design a filter with good performance based on the study of the clutter characteristics in a complex environment to suppress the clutter's influence on radar target detection.Therefore,the parameter estimation of the clutter and the design of the clutter suppression filter are two important aspects to realize the effective suppression of the clutter.Aiming at these two important issues,this article first derives the clutter type and spectrum estimation method based on the amplitude and frequency domain characteristics of the clutter,and then uses simulation experiments to illustrate the good performance of the clutter suppression filter designed in this article.The main research content of this article includes the following two aspects:1.Researched different clutter suppression algorithms and performance analysis of the algorithms.After comparative analysis,the recursive clutter suppression filter has better performance than the conventional clutter suppression filter in terms of clutter suppression and target loss.However,because conventional filters are difficult to adapt to the dynamic changes of clutter when suppressing clutter,and the application of recursive filters in radar systems is limited,this paper further studies the design method of adaptive filters for clutter suppression,which can be According to the dynamic change of the clutter,the relevant parameter settings of the algorithm can be adjusted adaptively,not only can effectively suppress the fixed clutter,but also the motion clutter is also very effective.Moving target display and moving target detection are the two most effective methods for clutter suppression.The performance analysis and research of these two algorithms show their superiority in clutter suppression.Aiming at the shortcomings of these two algorithms,the clutter suppression performance of the fast Fourier transform cascaded MTI filter bank and digital synthesis filter bank is further studied.Although the FFT cascaded MTI filter bank has the characteristics of simple design and high computational efficiency,the main lobe of the clutter suppression channel after the cascade will be deformed,which affects the performance of the filter bank.In response to this problem,the digital synthesis filter bank can effectively control the main-sidelobe ratio to improve the filter's clutter suppression performance.Finally,simulation experiments verify the performance of the above filter design methods,and the results show that the digital synthesis filter bank is not only simple in design,but also has better clutter suppression performance.2.Propose a filter design method based on clutter parameter estimation.Aiming at the estimation problem of center frequency and bandwidth,this paper uses clutter map technology to estimate clutter parameters,and adopts improved spectrum selection method and centroid method to accurately estimate the clutter frequency center and spectrum width.Aiming at the problem of clutter suppression zero notch error,it is proposed to use the estimated clutter parameters to reconstruct the autocorrelation matrix,and then use the minimum mean square error criterion to achieve the optimal filter design to achieve better clutter suppression performance.The performance of the designed filter can be improved through reasonable selection and control of the disturbance of the reconstructed clutter autocorrelation matrix,the clutter spectrum width,and the clutter power.the filter design method based on clutter parameter estimation proposed in this paper can effectively control the clutter suppression filter concave The width,depth and position of the mouth have good flexibility and adaptability to complex clutter.