A Dynamic Modeling And Simulation System For The Searching State Of A Terminal Guidance Radar

Correct and efficient search of targets in airspace is the prerequisite for accurate guidance in a terminal guidance radar system.The search process is modeled and simulated in this thesis.The content consists of three parts including echo signal model,signal processing analysis,and measured data analysis.The performances of the core algorithms in each related modules are verified by simulation experiments.First,the basic knowledge of echo signal model is introduced.The thesis gives a clear definition of the involved coordinate systems,and deduces the conversion relationship between different coordinate systems.The radar equip with the low-loss spot beam arrangement mode in the airspace search and the missile's movement modes are considered form three aspects such as rotational motion,ascending motion and disturbance.The impact of missile's ascent motion on the coverage of the pitch beam is analyzed in this thesis.The echo signal model is also illustrated by transmission signal,target echo signal and sea clutter at final.Then,the signal processing technologies are analyzed and simulated in this thesis.Based on the simulated IF echo,the low-pass filtering method with better image rejection performance is used to produce baseband signal.Besides,the principle of pulse compression technology is illustrated and the effect of windowing on signal-to-noise rate after pulse compression is analyzed.Then,a filter based on clutter characteristic is designed for clutter suppression.Finally,an appropriate method is chosen to perform false alarm detection on the results of clutter suppression and determine whether the target exists and find out the target's information like distance and speed.Considering the target can be detected in multiple range bins and azimuth elevation beam positions simultaneously,the target aggregation is performed on the detections in four dimensions including range,Doppler,azimuth,and elevation to ensure that only one detection result is retained for each target in each dimension.In addition,the track initiation and correlation algorithms are introduced and used to process the condensed trace point and generate the target track.Finally,the simulation results verify the performance of the track initiation and correlation algorithms.Finally,based on the aforementioned content,the GUI software is designed and the measured data is processed.The designed GUI software integrates various functions of search system and can be used for reference in other terminal guidance radar systems.