Airborne Radar Sea Clutter Modeling And The Implementation Of Its Simulator

Airborne radar bears significant application value in naval reconnaissance,maritime search and rescue,resources exploration and maritime operations fields.However,the airborne radar system will be inevitably affected by the sea clutter,in the complex and volatile marine environment.Therefore,the study of the characteristics of sea clutter will contribute to the design of radar system,theoretically.What’s more,the sea clutter simulator has the capable of verifying the actual performance of radar system in radar systematic implementation period.So,it is of great significant value to study the modeling of sea clutter and the simulator of sea clutter in airborne radar system in theory and engineering.Focusing on the modeling of sea clutter and the design and implementation of sea clutter simulator,this thesis mainly carries on the following work:1.Several major sea surface factors that affecting the characteristics of sea clutter are analyzed and summarized.Based on this,the statistical characteristics of sea clutter amplitude,time and space correlation characteristic are studied,and statistical models of sea clutter amplitude are researched.Furthermore,the geometric model and echo signal model of airborne radar operating in the marine environment are established,which lays the theoretical foundation for the sea clutter modeling and simulation.2.Two kinds of classical sea clutter modeling and simulation methods are studied: ZMNL(Zero Memory Nonlinearity)method and SIRP(Spherically Invariant Random Process)method,in this paper.The efficient time domain filter operator is designed to generate the relevant Gaussian sequence that needed in the process of simulating sea clutter sequence.Four amplitude models of sea clutter sequences are simulated and their amplitude distribution characteristics and related properties are verified.3.Based on SIRP method,the hardware implementation scheme of sea clutter simulator is proposed.Based on Jacobi rotation method,the FPGA(Field-Programmable Gate Array)implementation scheme of matrix eigenvalue decomposition is researched to generate the time domain filter,in sea clutter simulator.According to the actual situation,the communication protocol between the host computer software and the sea clutter simulator board is designed,and the communication data frame format is designed,as well.The MFC(Microsoft Foundation Classes)framework is selected as the basic framework of the sea clutter simulator man-machine interface.4.Implementation and verification of Sea Clutter Simulator system.Firstly,the design and debugging of the hardware circuit of the Sea Clutter Simulator are completed.Then,the application software of the host computer is composed to realize the efficient human-computer interaction and the data exchange between the machines.According to the Jacobi matrix eigenvalue decomposition method,program Verilog program to generate time-domain filter operator.Based the flow of SIRP simulating sea clutter,write hardware program to simulate correlation K distribution sea clutter sequence.Finally,the sea clutter sequence in the sea clutter simulator is collected,by chipscope tool,and the amplitude statistics and correlation properties of the sea clutter sequence generated by the simulator are verified in the MATLAB tool.The sea clutter simulator system,based on the SIRP method,can efficiently generate the relevant K-distribution sea clutter sequence,which is instructive for the design of the radar system working in the marine environment.