Key Technology Of Radar Echo Simulation For Extended Target

Radar,as a main means of target locating and tracking,has been playing an increasingly important role in military activities in recent years,which has promoted the development of radar to higher resolution and wider bandwidth.It brings a series of new topics on radar development,of which the target characteristic is an unavoidable problem.However,with the development of high-resolution radar,the traditional radar simulation system doesn't suit for the purpose of providing a variety of target environment scenarios for the daily military training,combat exercise or high-resolution radar development.The article gives the development process of radar echo simulation system based on the theory of multi-scattering center of target.And carried on the detailed explanation of based principle,project building and output signal processing.The main work and innovation ports of the paper are as follow:(1)Extending the construction method of traditional point-target radar signal simulation system to the extended-target radar signal simulation system.In the theory of multi-scattering center,some targets,such as airplane,ship and tank,can be classified as expansion targets when using HRRP,Radar echoes of the extended target can be equivalent to a large number of scattering units' echoes,each scattering on target can be equivalent to point-target.Therefore,the construction of the extended target radar signal simulation system can follow the basic idea of traditional point-target radar signal simulation system to use direct digital synthesizer(DDS)to simulate the scattering units,so the extended target can be modeled with multiple DDS.In this paper,we do a lot of work on analysis of the radar signal simulation scene,the simulator generation based on the DSP + FPGA + DAC hardware structure and explanation of the common problems,the display of the simulation system and the verifying process of the target echo.(2)Put forward the fast method of echo generation based on multi-scattering center impulse response convolution.In the theory of multiple scattering centers,the process of reflecting the radar emission on each scattering center of the target can be considered as a linear system.The system only changes the phase and amplitude of the radar emission.From this point of view,we put forward the method of building impulse response function of each scattering center and then construct the radar echo system's function to realize the process of echo simulation.In this article,we discussed systematically of The theoretical basis on the impulse response convolution method and the detailed work and flow of each module in the course of practice.The correctness and practicability of the method are verified by engineering practice.(3)Analyze the advantages and disadvantages of the two method of constructing extended target radar signal simulation system based on DDS and the impulse response convolution.First of all,we analyze the resource consumption of two methods,the implementation method based on DDS requires a large number of hardware IP core.However,the method based on the impulse response convolution doesn't need DDS,so it is clear that the method based on the impulse response convolution spends less hardware resources when the DSP has good performance,it's more economical.Secondly,we compared the complexity of two method and the computation of the two algorithms.In this paper,the real time cost of the algorithm and the computing time are analyzed.The results show that the method based on the impulse response convolution is more economical and the hardware resource consumption is more efficient when the DSP has good performance.The DDS-based radar signal synthesis method is more efficient when the number of scattering points is small,and the method based on impulse response convolution is more efficient when the number of scattering points is large and the computing time is not wide.