机载MIMO雷达的机动目标参数估计技术研究

发布时间：2019-02-12 19:09

【摘要】：随着科技日新月异的发展,诸如导弹、飞机等目标具有越来越高的机动性,因此无论在军事防卫还是民航安全方面,对机动目标进行实时检测与精准参数估计的重要性日益加深。近些年兴起的新体制雷达—MIMO(Multiple-Input Multiple-Output)雷达由于其相比于传统阵列雷达的突出优势,自提出便受到高度关注。MIMO雷达采用波形分集和空间分集技术,在目标检测、参数估计等研究方向取得良好的应用效果。由于机载MIMO雷达发射相互正交波形,引入了发射自由度,使得系统自由度大大增加,因此在杂波抑制方面要优于传统机载雷达,为运动目标的参数估计提供了更好的应用。本文研究主要内容为在机载MIMO雷达体制下,实现对机动目标的相关运动参数的估计,文章结构如下:首先,本文的研究针对当前关注度较高的相干型MIMO雷达,借助此类模型介绍了MIMO雷达的原理,以及其独特的信号处理流程。同时构建了机载MIMO雷达的目标回波模型、杂波数据模型,并阐述了MIMO雷达的空时自适应处理的相关基础知识。其次,提出了基于最大似然估计的机动目标参数估计方法,该方法在已建立的雷达回波模型基础上,结合回波所含各分量的分布特性,推导并简化接收数据的概率密度函数,得到包含待估计参量(波达角、初速度和加速度)的代价函数,先估计出目标波达角,然后对机动目标初速度以及加速度进行联合估计,避免了三维搜索。该方法加入了正交波形,并利用单个脉冲回波数据完成参数估计,估计性能优异,但依然面临较大的运算量。最后,提出了基于CPT(三次相位变换)的机动目标参数估计技术。目标回波通过导向矢量建模得到,不考虑波形。该方法先通过三次相位变换得出只含加速度的关系式,并对其进行估计,随后补偿目标加速度,利用快速傅里叶变换结合匹配搜索得出初速度估计值。该方法不仅能够获得较高的参数估计精度,而且算法复杂度较低。
[Abstract]:With the rapid development of the technology, such as the missile, the aircraft and so on, the target has more and more maneuverability, so the importance of real-time detection and accurate parameter estimation of the maneuvering target is becoming more and more serious, whether in the aspects of military defense or civil aviation safety. The multiple-input multiple-output (MIMO) radar, which has emerged in recent years, has been highly concerned since it has a prominent advantage over the traditional array radar. MIMO radar has a good application effect in the research of target detection and parameter estimation. Because of the mutual orthogonal waveform of the on-board MIMO radar, the freedom of transmission is introduced, so that the degree of freedom of the system is greatly increased, and a better application is provided for parameter estimation of the moving target in the aspect of clutter suppression. The main content of this paper is to estimate the relative motion parameters of the maneuvering target under the system of on-board MIMO radar. The structure of this paper is as follows: First, the research of this paper is based on the high-attention coherent MIMO radar, and the principle of the MIMO radar is introduced with the aid of such models. and its unique signal processing flow. At the same time, the target echo model and the clutter data model of the on-board MIMO radar are constructed, and the basic knowledge of the self-adaptive processing of the MIMO radar is described. Secondly, based on the established radar echo model, the probability density function of the received data is derived and simplified based on the established radar echo model. At the cost function of initial velocity and acceleration, the target arrival angle is estimated, then the initial velocity and acceleration of the maneuvering target are combined and estimated, and the three-dimensional search is avoided. The method adds an orthogonal waveform, and uses single pulse echo data to complete the parameter estimation, and the estimation performance is excellent, but still faces a large amount of computation. Finally, a method of maneuvering target parameter estimation based on CPT (three-phase shift) is proposed. The target echo is modeled by the guide vector and the waveform is not taken into account. The method comprises the following steps of: carrying out three phase transformation to obtain a relational expression containing only the acceleration, estimating the relation, and then compensating the target acceleration, and combining the fast Fourier transform and the matched search to obtain the initial velocity estimation value. The method not only can obtain higher parameter estimation precision, but also has lower algorithm complexity.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN957.51

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