Extraction Method And Application Of Micro-Doppler Effect Of Radar Signals

Radar target recognition is an important academic direction today. It plays a very important role in the fields of battlefield surveillance, missile defense, life detection and so on. The forms of movements of targets are complex motions actually. The traditional identification methods can not meet the needs of applications of describing the states of targets’movement. In recent years, many scholars have found recognition technology based on the characteristics of the micro-Doppler of targets can be used as an effective means to identify the target accurately. Therefore, the researches on micro-features have attracted the interests of more and more researchers. There are some studies of the extraction methods of micro-Doppler in recent years, but few methods are researched in the case of bistatic synthetic aperture radar and the degree of attention for the clutter is not enough.The paper describes the concepts of micro-motion and micro-Doppler effect and establishes the model of radar target micro-Doppler effect. We obtain the theoretical expressions of micro-Doppler frequency induced by basic micro-motions such as vibration and rotation and find the relationship between micro-Doppler information and the movement states of targets. Then time-frequency analysis methods are studied and the performances of these methods are discussed. In this paper, combined with the displaced phase center antenna technique, an extraction method of micro-Doppler information induced by rotating targets is presented in the case of bistatic synthetic aperture radar. The theoretical expressions are derived and the simulations verify the correctness of the method. Further through analysis of the results obtained by simulations, parameters of describing rotation center position and the motion form are inversed. Compared with the actual values, it is better to prove the accuracy of the method. On this basis, we will explore a new method of helicopter detection based on micro-Doppler information generated by the movement of the main and tail rotor.