Research On The Methods Of Maritime Ship Detection Based On Spaceborne Copmact Polorimetric SAR Imagery

In recent years,satellite radar sensor technology has made great progress,synthetic aperture radar(Synthetic Aperture Radar,SAR)has shown a huge advantage in the marine monitoring,marine target detection and so on.As a new and special polarized SAR system,Compact Polarimetric SAR(CP SAR)has a favorably endowed advantage and wide application prospect due to its low cost,power consumption,extensive width and abundant ground information contained.Therefore,it is of great scientific significance and application value to study the ship target detection technology by spaceborne CP SAR.In this paper,according to ship detection requirement for spaceborne CP SAR,combining with constant false alarm rate(CFAR)method,the reconstructed full polarization information and CP characteristic parameters are used to construct the marine clutter background statistics based on the basic theory of CP SAR to achieve ship detection.The main work in this paper is as follow:1.Data simulation for the three mainstream CP SAR models is studied,and the simulation data for ship detection are obtained.Firstly,the scattering matrix and the covariance matrix of three CP modes are given in formulas.Furthermore,the principle of the three algorithms is explained.Finally,the principle of CP SAR characteristic parameters and target decomposition is briefly introduced.2.A reconstructed polarized entropy ship adaptive detection method based on generalized Gamma distribution(G?D)is proposed.Firstly,Collins algorithm is used to construct pseudo full polarized entropy.Secondly,G?D is used to fit the ocean background,the CFAR threshold can be calculated by G?D parameters which are estimated by method of log-cumulants(MoLC).Finally,the results validate that the proposed method has better performance.Moreover,the G?D-CFAR detection method is proved to be superior to the method based on likelihood ratio test.3.According to the idea of ship detection based on CP SAR characteristic parameters,an adaptive ship detection method based on power degree of polarimetion(PDoP)is proposed.First,according to the polarization and scattering intensity information difference between the ship and the ocean,PDoP is constructed.Secondly,the CFAR detection algorithm based on PDoP is proposed.Finally,the performance of the polarimetric image and PDoP image is analyzed experimentally,and the distribution model of the ocean background clutter is studied.The polarization degree method proposed in this paper is compared with the method in the relative literature to prove that the proposed method has better performance and wider applications.In recent years,satellite radar sensor technology has made great progress,synthetic aperture radar(Synthetic Aperture Radar,SAR)has shown a huge advantage in the marine monitoring,marine target detection and so on.As a new and special polarized SAR system,Compact Polarimetric SAR(CP SAR)is widely used in various applications due to its low cost,power consumption and extensive width.Therefore,it is of great scientific significance and application value to study the ship target detection technology by CP SAR.