Research On Radar Target And Clutter Difference Enhancement Method Based On Fractal

The radar distinguishes the target and achieves target detection by the difference between the target and the clutter in the echo.Among the various interference clutters of sea radar,sea clutter is the main factor affecting radar detection.The traditional statistical model-based method is prone to model mismatch in the application,resulting in the radar's ability to distinguish between target and sea clutter.Fractal theory has the characteristics of describing the mechanism of sea clutter generation,and can better distinguish radar targets from sea clutter.Therefore,this paper uses fractal theory to enhance the difference between radar targets and sea clutter.The specific research contents and results are as follows:(1)Research on radar target and clutter difference enhancement based on hybrid fractal features.For the existing Detrended Fluctuation Analysis(DFA)method,only one fractal feature is used,and the problem of radar target and sea clutter cannot be effectively distinguished under low signal-to-noise ratio conditions.A hybrid fractal feature is presented.The method enhances the difference between radar targets and sea clutter.Firstly,the FFA method is used to extract the fractal features of the fitted line intercept and the fitted residual.The analysis shows the characteristics of the two fractal features.Next,for their differences in the small-scale range,the mixed features are composed using the fitting residuals and intercepts.Finally,the hybrid fractal data is used as the regional component,and the effectiveness of the proposed method is verified by the measured radar data.The experimental results show that compared with the traditional DFA-based Hurst index method,this method can effectively increase the difference between radar target and sea clutter when the data length is short(2048 points).(2)Research on target and clutter difference enhancement method of navigation radar based on multifractal.When the number of sampling points of navigation radar sea clutter data is insufficient,the fractal method is difficult to distinguish between radar target and sea clutter,and multi-fractal Fluctuation Analysis(MF-DFA)method is used to analyze navigation radar sea clutter data.Increase the difference between radar targets and sea clutter.Firstly,the construction method of navigation radar sea clutter sequence is given.According to the constructed navigation radar sea clutter sequence,the MF-DFA method is used to verify the overall multifractal characteristics of the navigation radar sea clutter sequence,and the range of the scale interval is determined.Finally,considering the navigation radar sea clutter sequence as the random walk process and the incremental process,the MF-DFA method is used to calculate the multifractal index of the navigation radar sea clutter data.The experimental results show that the sea clutter data is used as the incremental process method,and the difference between the radar target and the sea clutter is obviously increased.When the number of sampling points is insufficient,the method has a good ability to distinguish between the radar target and the sea clutter.(3)Combining the algorithm given in this topic,an experimental verification platform is built.The implementation scheme of the experimental platform is given,and the specific functions of each module are designed.Finally,the experimental platform was designed and implemented.