TOPSAR成像及SAR-GMTI杂波抑制研究

发布时间：2018-05-17 09:13

本文选题：合成孔径雷达(SAR) + 地面运动目标检测(GMTI)　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：地面运动目标检测(GMTI)技术是星载合成孔径雷达研究中一个重要的研究内容。为了实现地面运动目标检测,星载SAR-GMTI系统需要工作在下视状态,这种情况下雷达系统会接收到来自地面的回波信号,包括地面静止杂波信号和运动目标信号。星载平台的运动速度很快,这会导致杂波的频谱展宽,并且地面上静止杂波的能量比运动目标的能量要强很多,在这种情况下直接进行运动目标检测,检测概率将会很低。所以为了提高目标检测概率,星载合成孔径雷达系统必须具备很强的杂波抑制能力,这也是实现GMTI功能的前提条件。本文主要对GMTI性能指标、TOPSAR成像和星载三通道SAR-GMTI自适应杂波抑制等几个方面做了研究,主要工作概括如下:(1)首先从GMTI相关的指标出发,介绍了虚警概率和检测概率以及最小可检测速度;接着介绍了在杂波非均匀的背景下星载SAR-GMTI对杂波环境的要求;最后介绍了相干性对GMTI性能的影响,其中主要研究了相干系数和杂波抑制性能的关系、垂直基线引起的去相干对GMTI的影响。(2)首先对TOPSAR的工作原理进行了分析,分别对工作模式和信号模型进行了分析;然后对TOPSAR成像算法进行了研究,采用了一种新的变标方式-BAS算法,仿真结果和对实测数据的处理结果均验证了该方法的有效性。(3)研究了星载三通道SAR-GMTI自适应杂波抑制方法,首先对多孔径技术进行了介绍,详细介绍了多孔径的概念和多孔径SAR-GMTI处理方法,然后对基于自适应杂波抑制的多通道SAR-GMTI方法进行了改进,提出了一种星载三通道SAR-GMTI自适应杂波抑制方法,此方法考虑了相邻多普勒单元的相关性,仿真结果验证了该方法的有效性。
[Abstract]:Ground moving target detection (GMTI) is an important research content in spaceborne synthetic aperture radar (SAR). In order to realize ground moving target detection, spaceborne SAR-GMTI system needs to work in a down-looking state. In this case, radar system will receive echo signals from the ground, including ground static clutter signal and moving target signal. The moving speed of the spaceborne platform is very fast, which will result in the broadening of the clutter spectrum, and the energy of the stationary clutter on the ground is much stronger than that of the moving target. In this case, the detection probability will be very low if the moving target is detected directly. Therefore, in order to improve the probability of target detection, spaceborne synthetic Aperture Radar (SAR) system must have a strong clutter suppression ability, which is also a prerequisite for the realization of GMTI function. In this paper, the performance index of GMTI / TopSAR imaging and the adaptive clutter suppression of spaceborne three-channel SAR-GMTI are studied. The main work is summarized as follows: (1) starting from the index of GMTI, The false alarm probability, detection probability and minimum detectable speed are introduced, then the requirements of spaceborne SAR-GMTI for clutter environment under the background of heterogeneous clutter are introduced. Finally, the effect of coherence on the performance of GMTI is introduced. The relationship between coherence coefficient and clutter suppression performance is mainly studied. The effect of deconcentration caused by vertical baseline on GMTI is analyzed. Firstly, the working principle of TOPSAR is analyzed, and the operation mode and signal model are analyzed respectively. Then, the TOPSAR imaging algorithm is studied, and a new scale-varying BAS algorithm is adopted. The simulation results and the processing results of the measured data verify the effectiveness of the method. (3) the adaptive clutter suppression method for spaceborne three-channel SAR-GMTI is studied. The concept of multi-aperture and the processing method of multi-aperture SAR-GMTI are introduced in detail, and then the multi-channel SAR-GMTI method based on adaptive clutter suppression is improved. A novel adaptive clutter suppression method for spaceborne three-channel SAR-GMTI is proposed. The correlation of adjacent Doppler units is considered in this method. The simulation results show that the proposed method is effective.
【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】：2014
【分类号】：TN957.51

【相似文献】