The Research Of The Target Recognition Techniques Based On The Micro-doppler Features Of The Aircraft

In usual cases,during the moving of the aircraft,the aircraft may have small rotations or vibrations or other higher-order motions in addition to mass translation,which is called micro-motion.For example,the propeller of the airplane,the turbine of the jet engine,the screw vane and the empennage of the helicopter,the reverberate signal has rules with the time changing.The backscatter of a target with micro-motions contains fine micro-Doppler features,which enables us to determine some unique properties of the target.Different aircraft have different micro-Doppler features,we can use these features to classify different targets.In this paper, based on the current domestic and international latest radar target recognition and statistical theory,directing at the physical structure characteristics of radar target scattering mechanism,discussed the modulation phenomenon.Raised the modulation features which can be used for classification, modeling and simulating, and collected a large number of real data to test and verify the model and the modulation phenomenon, achieved good results.The main job content of this paper is as follows:Firstly, analyzed the physical structure characteristics of the different scattering mechanism goals in detail, different structures of the target produce different echo; secondly,modeling and simulation, and substituted the actual target structure parameters and the actual radar parameters,obtained the modulation characteristics of different aircrafts,including the phase and frequency modulation characteristics.relying on a large number of real data, verify the accuracy of echo model, and found a group of steady and well distinguished micro-Doppler features for the Classification of the aircrafts;thirdly, put forward a method of using cycle features in frequency and phase shifted angle and amplitude offset ratio to design a classifier based on nearest neighbour rules, analysed the effect of the classifier;lastly,analysed the needed radar parameters which can get uncovered and steady cycle features in frequency.