Multi-granularity Modeling And Simulation Of Radar Seeker

Considering the application of the radar seeker system, the study of multi-granularity modeling of radar seeker system is of great significance. Modeling radar seeker system with different particle sizes effectively eases the contradiction between the model complexity and simulation efficiency and satisfies the applications under various needs.This dissertation mainly focuses on the study of the multi-granularity modeling and simulating of the radar seeker system based on the general framework of the radar seeker system. First of all, according to the hierarchical structure of the radar seeker system and the method of multi-granularity modeling, three granularity structures of the radar seeker system are proposed and the simulation of the radar seeker system is divided as signal-level simulation, subsystem-level simulation and function-level simulation. And then the signal-level, subsystem-level and function-level simulation system are modeled respectively.Signal-level simulation belongs to the fine-grained model. Based on the real signal processing of radar seeker, signal-level simulation vividly reconstructs the entire process of the production of the transmitted signal, the formation of echo after environmental reflection, reception, signal processing, data processing and control of the missile tracking target.Function-level simulation is coarse-grained model without the echo signal, but by the parameters and the gain to describe the overall function of the radar seeker system. Radar equation is used to calculate the echo power of target, noise, clutter and interference, while the power gain got by the signal process is obtained by the power spectrum density and the frequency response function, detection and measurement is thus proceeded based on the signal-to-noise(SNR) after the power accumulation(coherent and non-coherent). Data processing and guidance control are the same with the signal-level simulation.On the basis of comprehensive analysis of the signal-level and functional-level simulation methods, the sub-level simulation model is proposed. Subsystem-level simulation is still by getting the echo power of target, noise, clutter and interference, SNR is calculated to obtain the probability of detection, and then determine whether the target is detected or not. The main difference between the subsystem-level simulation and functional-level simulation is the processing corresponding to the true target, the signal power is obtained by simplifying the processing of the signal level. Compared to the functional-level simulation, the subsystem-level simulation is more credible because it uses the effective echo corresponding to the real target.Finally, we discuss the consistency of simulation models with different particle sizes from the behavioral level and structural level. The simulation results of different particle size systems are given under the same system parameters. The simulation results show that the proposed different size systems are consistent with each other, while external interfaces of different size models also meet the consistency. In addition, the comparison of simulation time of the three systems is also done. Compared to the signal-level simulation, the signal processing of the subsystem-level simulation is simple and thus cost less time. Compared to the functional-level simulation system, the subsystem-level simulation cost more time since the SNR is calculated using the real echo. The simulation results also proved the subsystem-level simulation time is between the signal level and functional level simulation.