多帧联合检测与跟踪技术研究

摘要

摘要

如何在复杂探测环境中实现对微弱（低信噪/杂比）目标的稳定检测与精确跟踪是雷达领域一项重要的共性基础研究，在防空反导、战略预警等领域具有重要意义。相比传统方法，多帧联合检测（MFD）技术可直接对若干连续的原始回波数据进行联合信号处理，并利用目标与背景（噪声或杂波）帧间相关性的差异提高多帧积累统计量的信噪比，从而改善算法性能。大量研究表明，MFD技术对弱小目标检测效果显著，但现阶段在理论、方法以及工程实践等方面仍然不够完善，存在许多亟待解决的问题。例如：机动目标场景中的算法搜索维数灾难、利用滑窗结构MFD技术实现目标长时间跟踪时，所得航迹不连续且跟踪精度差等。

本论文主要围绕MFD技术的上述问题展开相应的研究，主要工作如下：

1、结合雷达系统，研究了MFD算法的建模方法。针对MFD技术中多帧统计量的选择和迭代优化方法的设计两个关键问题，分别研究了其各自内在的机理，并分析了不同选择设计方案下算法的优缺点及适用条件。

2、针对机动目标应用需求，分析了传统MFD方法的问题和难点。提出了一种改进的MFD算法。该方法可有效地平衡机动模型精确度与MFD搜索复杂度之间的矛盾关系，改善算法对机动目标的探测能力。

3、针对MFD所得航迹不连续且跟踪精度差等问题，分析了滑窗批处理MFD 的结构特点，研究了一种多帧联合检测与跟踪（MFDT）的技术方案。针对该技术方案，提出了一种适用于“航迹片段”的平滑滤波算法，该方法可有效降低目标航迹丢失率提高估计精度，并获得连续完整的航迹，实现对目标持续稳定的跟踪。

4、针对所提MFDT技术，研究了一种基于多通道并行处理的优效工程实现方案，可利用滑窗结构特点有效提高算法的实时性。

以上提出的算法和工程方案均已通过仿真实验或雷达实测离线处理测试，并完成了与传统方法的性能对比分析，证明了所提方法的有效性。

关键词：微弱目标探测，多帧联合检测技术，机动目标，雷达系统

ABSTRACT

How to achieve stab le detection and accurate tracking for dim tar gets in complex environment is an im portant common research in radar system s, which is of great significance in the fields of air defense and early warni ng. Compared with traditional methods, the m ulti-frame detection (MFD) t echnique can directly process sev eral consecutive raw echo data and enhance th e signal-to-noise-ratio of multi-frame accumulated statistics through the difference of the correlation between the tar get and the background (noise or clutter), thereby improving the algorithm performance. A large number of studies have shown that MFD tec hnique has significant effect for dim target detection, but it is still not perfect in theory, method and engineering practice at present. There are many problems need to be solved ur gently. For example, existing studies on MFD are focusing on the non-maneuvering or slowly maneuvering target scenes. When using sliding window based MFD to achieve long tim e target tracking, the obtained track is not continuous and with poor accuracy.

This paper mainly focuses on the problem s of MFD above, and the m ain contents are as follows:

1. The MFD algorithm based modeling approach is studied, taking radar system as an example. The inherent m echanism of two key problems in MFD technique (i.e., the selection of multi-frame statistics and the design of iterative optim ization method) are studied respectively, and the advantages and disadvantag es of different selections and design schemes are analyzed.

2. In order to solve the problem of maneuvering target application, the difficulties of traditional MFD method are analyze d. An improved maneuvering target MFD algorithm is proposed, which can ef fectively balance the contradiction between the model accuracy and the MFD search com plexity, resulting in be tter performance for maneuvering target detection.

3. For the purpose of long tim e target tracking, this paper analyzes the structural features of the sliding window based MFD,and studies a technical schem e, namely, multi-frame detection and tracking (MFDT). A smoothing filtering algorithm suitable for MFD "track segm ent" is proposed, which can effectively reduce the track lo ss rate, improve the estimation accuracy, and obtain con tinuous and complete track to achiev e