Matrix CFAR Detection Method Based On Preprocessing

Sea surface target detection has always been the focus direction of sea clutter research.At present,for the problem of weak target detection which under the background of short pulse sequence and strong sea clutter,the traditional likelihood ratio test method can not make full use of the correlation between data.So its detection performance is poor.In recent years,information geometry develops rapidly.At this stage,the principles of differential geometry is generally used to study information science related issues,and has been widely used in image processing,information coding,signal analysis and other fields.Therefore,it is very important to study and analyze the application of information geometry in target detection and make full use of geometric information in matrix manifold.What's more,when the target doppler frequency is unknown,especially when the target spectrum is separated from the clutter spectrum,it is also important to design an effective preprocessing mechanism.To this end,this thesis mainly does the following work:1)Some problems of radar target detection under the background of short pulse sequences and strong sea clutter are discussed.And the development and research status of radar target dection is summarized.Some basic theory of signal detection and the mathematical concept of matrix information geometry are introduced,which lays a foundation for the derivation of geometric mean.2)Using the matrix manifold,the radar target detection can be resolved by the information geometry.According to both the new geometric measures and the corresponding mean matrix on the matrix manifold,two new matrix CFAR detectors are proposed in this thesis.The two normalized distances of Frobenius norm are measured in the proposed matrix CFAR.The computational complexities of the two normalized distances are same and very low.Finally,experimental results show that the two normalized distances of Frobenius norm exhibit the similar detection performance and are superior to the existing matrix CFAR detectors based on distance.3)For the target detection in the short pulse sequences and strong sea clutter environment,we consider the preprocessing of the received signal through time-frequency analysis.And we propose a matrix CFAR detection method which based on the maximum eigenvalue in this thesis.When the target doppler frequency deviates from the clutter spectrum center,the clutter suppression solves the failure of the matrix CFAR method.Finally,the simulation results show that the proposed method has better detection performance.4)Moving target detection is based on the energy difference between the target and the clutter.Generally,various filters are used to filter out the clutter to distinguish the moving target.Based on this phenomenon,we use the principle of moving target detection,and propose a matrix CFAR detection method which uses sub-band filter banks to filter the received data.Then we combine with the maximum eigenvalue to achieve the useful target signal.Finally,the research shows that this method has better detection performance.