Micro-Doppler Extraction And Parameter Estimation Of The Space Target Based On General Parameterized Time-frequency Analysis

The micro-Doppler features can reflect the electromagnetic scattering characteristics, geometric structure and motion characteristics of the target, so they are considered as important signatures for the classification and recognition of ballistic missiles. Considering the advantages of highly concentrated time-frequency representation and no cross-terms, the general parameterized time-frequency transform proposed in recent years becomes a powerful tool in analyzing the non-stationary signal such as the radar echo induced by micro-motion.In this paper, based on the general parameterized time-frequency transform, firstly the method to estimate the translational parameters and extract the micro-Doppler of the cone-skirt shaped target is proposed, and then the micro-Doppler and inertia ratio of the cone shaped target with occlusion effect is estimated. The dissertation can be summarized as the following two points:1. A method to estimate the translational parameters and extract the micro-Doppler of the cone-skirt shaped target is investigated. There exist two problems: 1) It is easily wrong to track the frequency points considering the more scattering points; 2) The Doppler modulation induced by the translation may affect the extraction of the micro-Doppler. Based on the general parameterized time-frequency transform, the scatterers' echoes are separated with the multi-component signal decomposition to avoid tracking the wrong way, and the translation parameters can be accurately estimated to decrease the error. In the simulation experiments, our proposed method is evaluated based on the electromagnetic computation data.2. Study on the cone shaped target with occlusion effect. When the rotation axis of the target dose not coincide with the radar line of sight, some parts of the target will be unsighted to radar, which is referred to as occlusion effect. However, this factor is seldom considered in the traditional methods. The consecutive discontinues measurements are filled in based on the echoes of symmetrical distribution scatterers. Considering the target with widespread scatterers, the partial parameters are firstly estimated via the coherent single range Doppler interferometry algorithm, then the discontinues measurements are filled in based on the time invariant property of stationary signal, and finally the micro-Doppler are extracted via the general parameterized time-frequency transform. The inertia ratio is estimated based on the extracted micro-Doppler. Our proposed method is evaluated based on the electromagnetic computation data of two kind targets.