The Simulation Technology Of Fuze Ground Echo Intermediate Frequency Signal Based On Virtual Instrument

Radio fuze is a device for target detection and explosion control of the ammunitions by using the electromagnetic scattering of the target.The target of ground-acting fuze is the ground,which can be detonated at the best explosion point from the ground.The target echo signal simulation technology plays an important role in the research on modern radio fuze.With the improvement of radar resolution,the ground is now defined as a distributed body target,rather than the point target.Based on fractal terrain,this thesis proposed an improved method of body target echo simulation.The main works of the thesis are as follows:1)This thesis discusses the basic principle of three typical fuze signals,which are triangle LFM,continuous wave Doppler and pulse Doppler.According to the motion posture of projectile and target in near-field intersection,the simulation model of fuze echo signal is proposed based on radar equation and backscattering coefficient.The theoretical simulation are then presented and analyed.2)The random midpoint displacement method of fractal theory is used to model three-dimensional terrain.Combining the data of digital elevation model(DEM)and the characteristics of fractal theory,an improved random midpoint displacement method is proposed to optimize the "spike phenomenon" and "fold phenomenon" of fractal terrain,so that the simulated terrain is closer to the natural terrain.3)This thesis proposes a method of echo simulation for body target based on fractal terrain.Based on the DEM data of terrain,the scattering elements are divided by the distance ring-azimuth method.And then combined with the position information of the fuze the parameters of the scattering elements,such as the scratch angle and the radar cross section(RCS),are calculated.The echo signals of all scattering elements in the area are modeled,and finally the echo signals of the body target are superimposed.4)The whole system is designed and implemented by MATLAB and LabVIEW joint programming,which ensures the compatibility and operational efficiency of the system.Based on the RF signal transceiveing instrument of NI company,the ground echo signal is simulated,and the echo analog signal is observed and analyzed through experiments.