Font Size: a A A

Micro-doppler Signature Analysis Of Radar Targets And Its Applications

Posted on:2015-05-05Degree:DoctorType:Dissertation
Country:ChinaCandidate:G F ChenFull Text:PDF
GTID:1108330464468881Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
With the rapid development of target recognition technology, various anti-detecting and anti-recognition technologies have obtained the fast development, which has brought new difficulties for the detection and recognition of targets, and also proposed higher technical requirement about meticulous description and details of the motion of the target. Micro-Doppler signature produced by micro-motion contains movement and structure information of the target, and target inherent characteristics can be extracted from them. Since the micro-Doppler signature of radar target is found, the important values of micro-Doppler signature in target detection, classification and recognition have caused extensive concern of Domestic and foreign academic and engineering fields. Therefore, making further research on micro-Doppler signature and its application of radar target has important theoretical and application value in military and civil fields.In this dissertation, the following aspects are investigated, i.e., mathematics analysis of micro-Doppler features, micro-Doppler signatures extracting method, micro-motion signal separating method, parameter estimation of micro-motion and target recognition based on micro-Doppler signatures. The main work of this dissertation is as follows:1. The principles of micro-Doppler signatures are researched. And the typical micro-motion models of acceleration motion, vibration motion, rotation motion and coning motion are set up. Moreover, mathematical formulas of micro-Doppler signatures of them and the corresponding relationships between them and the micro-motion parameters are deduced. Because of the complexity and difference of micro-motion, based on non-rotor targets and rotary-wing targets, complex motion scattering point with translation, acceleration and vibration is modeled, so is complex motion scattering point with translation, vibration, acceleration and rotation. Then their micro-Doppler signatures, their differences and the relationship between the target structures and micro-motion parameters are studied, which will provide the theoretical foundation for recognizing the two kinds of targets.2. Aiming at the extraction of micro-Doppler signature, the common methods of extracting micro-Doppler signatures from the echo of radar are introduced and their advantages and disadvantages are compared. Then the method of extracting microDoppler signature using smooth pseudo Wigner-Ville distribution is proposed. Moreover, the influences of translational velocity, acceleration, radar carrier frequency and radar PRF on micro-Doppler feature extraction and their corresponding solutions are discussed, which will provide theoretical guidance for effectively extracting micro-Doppler signature.3. The separation method of the target main body signal and micro-motion signal based on the Radon transformation is proposed. Firstly, time-frequency transform of the echo signal is performed, and then the target main body signal and micro-motion signal is separated by the Radon transform in the time-frequency plane, furthermore the time-frequency distribution of separated signals is obtained by inverse Radon transform. According to study of the micro-motion in which the micro-Doppler feature is mostly shown Sinusoidal frequency modulation signals, the separation method of Sinusoidal frequency modulation signals based on correlation searching and time-frequency analysis is proposed. Firstly, time-frequency analysis method is used to estimate signal category and the range of parameters in time-frequency plane, furthermore correlation searching method is used to search related parameters for separating sinusoidal frequency modulation signals.4. A micro-motion parameter estimation method by extracting time-frequency analysis matrix maximum along the frequency and least square fitting straight line method is proposed. Using the method, the acceleration, the vibrational frequency and amplitude of complex micro-motion target with vibration and acceleration are effectively estimated, so are the acceleration, rotational frequency and rotational radius of complex micro-motion target with rotation and acceleration. Based on that, the micro-motion model of the rotating linear rigid body is set up and its micro-Doppler signature is quantitatively analyzed, furthermore, the rotational angular velocity and the length are effectively estimated. Moreover, the motion dynamics and echo models of the blades of helicopter are set up, and the micro-Doppler signature of the blade and the relations of micro-Doppler signature and parameter of the target are quantitatively analyzed, then the rotor rotational angular velocity, rotor length and rotor blade number are effectively estimated, which will provide foundation for accurate recognizing target.5. Aiming at the recognition problem of true and fake warheads, the models of cone warhead with precession or notation and decoy with swing are established. Then their micro-Doppler signatures are analyzed and compared. It is shown that the micro-Doppler signatures of precession, notation and swing are significantly different, so the method using the difference of micro-Doppler signatures to recognize true and fake warheads is proposed. In order to recognize the wheeled vehicle and the tracked vehicle in ground battle, the motion dynamics and echo models of the scattering point on wheeled vehicle and tracked vehicle are set up respectively. Then the micro-Doppler signatures of them and their difference are studied, moreover the method using the difference of micro-Doppler signatures to recognize wheeled vehicles and track vehicle is proposed.
Keywords/Search Tags:Radar target recognition, Micro-motion, Micro-Doppler, Micro-motion model, Complex motion, Feature extraction, Time-frequency analysis, Signal separation, Parameter estimation
PDF Full Text Request
Related items