基于高程地图的机载雷达近程异构杂波抑制方法研究

发布时间：2018-05-12 08:16

本文选题：STAP + 高程地图　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：在机载雷达地杂波抑制问题中,传统的空时自适应处理(STAP)算法假设杂波环境是均匀的且回波数据满足独立同分布的条件,在理想条件下可以达到杂波抑制效果。但是由于地形起伏实际中多为非均匀环境,均匀环境下的杂波模型不再适用,传统STAP算法性能下降较为严重,有很大的局限性。因此,本文在机载相控阵雷达的背景下,从基于高程地图的机载雷达杂波通用模型的建立和相应的近程异构杂波抑制方法两个方面进行研究。首先,提出创建山形高程地图、判断遮挡和杂波计算的方法,建立杂波通用模型,最终得到非均匀杂波功率谱。然后,在非均匀杂波模型的基础上,通过两维两脉冲对消思想和直接数据域方法对近程异构杂波进行抑制。这两种方法可以避免杂波协方差矩阵估计偏差造成的杂波抑制性能下降,在非均匀环境下可达到较好的杂波抑制性能。此外,还提出载机航迹规划的两条准则。本文的主要工作内容如下:1.第二章主要介绍机载相控阵雷达均匀环境下杂波模型和抑制方法。首先,对均匀环境下的杂波几何模型进行介绍。然后,介绍了最优STAP原理。最后,介绍了几种较为经典的固定结构降维STAP的原理,分别为联合局域化(JDL)、因子化方法(FA)、扩展因子化方法(EFA)。由于EFA比FA系统自由度大,因而性能较FA更优。2.第三章提出了基于高程地图的机载雷达杂波通用模型的建立及分析方法。首先,提出了一种建立高程地图的方法。然后,提出了利用单调性变化情况判断遮挡的方法,并对杂波回波进行计算。最后,进行了相关的仿真实验与分析。通过仿真结果可以得出近程、中程、远程条件下的杂波功率谱分布以及频谱“搬移”情况。本文提出的杂波模型为通用模型,通过以矩阵形式输入高度信息,就可以得到对应的杂波功率谱。3.第四章提出基于高程地图的近程异构杂波抑制方法。两维两脉冲利用载机速度和雷达参数等先验信息,通过相邻脉冲相减构造误差函数,最小化误差函数以获得滤波器系数矩阵,降低了杂波自由度。直接数据域属于非统计类算法,直接对回波数据进行处理,可应用于非均匀环境。此外,针对实际工程需要,在理论上提出了载机航迹规划的两条准则。仿真实验表明,本文的方法可以有效对近程异构杂波进行抑制,性能较传统降维STAP有较为明显的提高。
[Abstract]:In the ground clutter suppression of airborne radar, the traditional space-time adaptive processing (STAP) algorithm assumes that the clutter environment is uniform and the echo data meet the independent and identically distributed condition, and the clutter suppression effect can be achieved under the ideal condition. However, because the terrain undulation is mostly inhomogeneous, the clutter model under the uniform environment is no longer. Applicable, the performance of the traditional STAP algorithm is more serious and has great limitations. Therefore, in the background of the airborne phased array radar, this paper studies the establishment of the general model of the airborne radar clutter based on the elevation map and the corresponding near range heterogeneous clutter suppression method in two aspects. First, the mountain elevation map is created to judge the occlusion. In the method of blocking and clutter calculation, a general model of clutter is established, and the nonuniform clutter power spectrum is finally obtained. Then, on the basis of the nonuniform clutter model, the two dimensional two pulse cancellation idea and direct data domain method are used to suppress the short range heterogeneous clutter. These two methods can avoid the miscellaneous of the miscellaneous covariance matrix estimation deviation. The performance of wave suppression is reduced and good clutter suppression performance can be achieved in non-uniform environment. In addition, two criteria for carrier track planning are also proposed. The main contents of this paper are as follows: 1. second chapters mainly introduce the clutter model and suppression method under uniform environment of airborne phased array radar. First, the geometric model of clutter under uniform environment Then, the optimal STAP principle is introduced. Finally, several classical fixed structure dimensionality reduction STAP principles are introduced, which are combined localization (JDL), factorization method (FA) and extended factorization method (EFA). Because EFA is more free than FA system, the performance is better than FA better.2. third chapter based on elevation map based airborne mine. In the first place, a method of building elevation maps is proposed. Then, a method to judge the occlusion using the variation of monotonicity is proposed, and the clutter echo is calculated. Finally, the related simulation experiments and analysis are carried out. The simulation results can be used to obtain the short range, middle range and remote conditions. The clutter power spectrum distribution and the spectrum "move" situation. The clutter model proposed in this paper is a general model. By inputting the height information in matrix form, the corresponding clutter power spectrum.3. fourth chapter is proposed to propose a close range heterogeneous clutter suppression method based on the elevation map. The two dimension two pulse uses the carrier speed and the radar parameters, etc. Prior information is used to construct error functions by subtraction of adjacent pulses and minimize error functions to obtain filter coefficient matrices and reduce clutter freedom. Direct data domain is a non statistical algorithm, which directly deals with the echo data and can be applied to non-uniform environments. In addition, the aircraft carrier navigation is proposed in theory for actual engineering needs. The simulation experiments show that the proposed method can effectively suppress the short range heterogeneous clutter, and the performance of the two criteria is more obviously improved than the traditional dimension reduction STAP.

【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN959.73

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