Ballistic Missilemicro-doppler Characteristic Parameters Extraction Method Investigation

As a long-range detection tool,radar can effectively measure distance,angle and velocity of a moving target.With the continuous improvement of radar technology,modern radar can be used to identify the target by utilizing it's extended function for the elaborate structure measurement and micro-motion feature extraction.However,because of the rapid development of target feature control technology in recent years,the non-cooperative targets like false targets and baits have been able to be imitated more accurately,which make the target recognition method that based on traditional features lose efficiency.How to accurately identify non-cooperation goals in military defense has become one of the most important tasks in the field of radar.The motion object modulates the frequency of the radar wave,causing the frequency of the echo to deviate from the emission frequency,and this phenomenon is called the Doppler effect.If there is some slight movement of its own structural parts in addition to the systemic velocity,it will cause additional frequency modulation on the echo signal to form the Doppler band edge which is associated with the targets,and this phenomenon is called the micro-Doppler effect.The micro-Doppler feature is the special characteristic of an object that is unique to other objects,and these features represent the elaborate frequency modulation from the structural parts of the object.Therefore,these unique characters can be extracted by virtue of these particular features that the targets possess,and can be used as a ballistic missile target recognition of new ideas and methods.In this thesis,we first introduce the background and significance of the topic and the development of the ballistic missile target identification.Then,we introduce the basic theoretical knowledge about the radar micro-Doppler effect and its characteristics,and paves the way for the development of the thesis.,the effect and characteristic of radar micro-Doppler and related basic theories.Based on narrow and broad band radar,we modeled the micro-motion targets,such as rotation,vibration,and processional motion,and make a analysis and discussion on the results.Next,based on time-frequency analysis,the method of extracting the micro-motion characteristic parameters of ballistic missile is discussed emphatically.The type of time-frequency analysis method,the warhead target motion modeling,the radar echo time-frequency characteristic and analysis,the micro-feature extraction method and simulation based on time-frequency analysis method are described in detail.At the same time,the simulation and analysis of the characteristic parameters of micro-motion are carried out with variable number of scatter points and signal to nose ratio(SNR).Finally,the other extract methods of ballistic missile micro-motion parameters are briefly summarized,and the cepstrum method and the time delay conjugation method are simulated and compared with the results time-frequency analysis method.It is proved that the time-frequency analysis method is relatively robust and reliable in the ballistic missile target identification,and the micro-motion parameters of the target can be extracted effectively.