高频地波雷达舰船目标检测研究

发布时间：2018-04-20 04:27

  本文选题：高频地波雷达 + 舰船目标检测　； 参考：《南京航空航天大学》2014年硕士论文

【摘要】：作为超视距探测的一种典型,高频地波雷达能够实现广泛区域内的全天候监测,因而得到了广泛的应用。低速运动的舰船类目标,在多普勒维受强大的海杂波影响,很难被高频地波雷达探测到。如何检测舰船类低速目标一直是高频地波雷达的研究难点,本文结合实际工程项目,从海杂波抑制、恒虚警检测、检测前跟踪等方面开展研究。主要工作如下:提出了基于局部相关性的改进子空间法海杂波抑制方法。在距离-多普勒维依据邻近距离单元的局部相关性,自适应划分海杂波相关区域,提高了基于协方差矩阵的奇异值分解和海杂波子空间划分准确性,实现了对海杂波更有效的抑制。实测数据表明,一阶海杂波功率下降15-20dB,目标信号信杂比提高10dB左右。设计了高频地波雷达的CFAR方案。基于某型高频地波雷达实测信号Weibull统计分布及多普勒维易产生虚假目标等特性,设计了PD-MLH-OS组合CFAR检测方案,包括:先进行距离-多普勒-方位三维峰值检测,再分别进行距离维MLH-CFAR检测,多普勒维OS-CFAR检测。仿真结果表明:检测概率80%时,所提检测方案优于CA-CFAR近5dB。针对目标漏检的情况,提出了基于隔帧外推的改进动态规划方法。研究了适合于解决低信噪比下弱小目标检测问题的基于动态规划的检测前跟踪算法,并针对原算法因目标RCS闪烁、海杂波覆盖等导致的漏检情况,提出了基于隔帧外推的改进动态规划方法。当第k帧不在第k?1帧的状态转移范围内时,考虑k?2帧到第k帧的状态转移。仿真分析了算法的检测有效性,保证了在某一帧漏检时最终检测结果不受影响,且在保证了检测概率的同时提高了运算速度。结合某实际高频地波雷达系统,基于脉冲压缩、数字波束形成处理流程,设计了由海杂波抑制、相干积累、恒虚警检测、动态规划检测前跟踪构成的高频地波雷达舰船目标检测方案。运用本方案的实测数据处理结果与船讯网AIS信息对比,验证了检测方案的有效性,可对90公里以内船长为150m左右的舰船目标实现连续检测和航迹形成。
[Abstract]:As a typical over-the-horizon detection high frequency ground wave radar can achieve all-weather monitoring in a wide range of areas and has been widely used. Low speed moving ship targets are hard to detect by high frequency ground wave radar because they are influenced by strong sea clutter in Doppler dimension. How to detect low-speed target of ship is always the research difficulty of high-frequency ground wave radar. In this paper, the research is carried out from the aspects of sea clutter suppression, CFAR detection and pre-detection tracking. The main work is as follows: an improved subspace method for suppression of sea clutter based on local correlation is proposed. Based on the local correlation of adjacent distance units, the range-Doppler dimension adaptively divides the correlation region of sea clutter, which improves the accuracy of singular value decomposition based on covariance matrix and subspace partition of sea clutter. More effective suppression of sea clutter is realized. The measured data show that the power of the first order sea clutter decreases by 15-20 dB and the signal-to-clutter ratio of the target signal increases by about 10dB. The CFAR scheme of HF ground wave radar is designed. Based on the characteristics of the Weibull statistical distribution of the measured signals of a high frequency ground wave radar and the easy to produce false targets in the Doppler dimension, a PD-MLH-OS combined CFAR detection scheme is designed, which includes: first, the range Doppler azimuth 3D peak detection is carried out. Then the range dimension MLH-CFAR detection and Doppler dimensional OS-CFAR detection were carried out respectively. The simulation results show that the proposed detection scheme is better than the CA-CFAR nearly 5 dB when the detection probability is 80%. An improved dynamic programming method based on frame extrapolation is proposed for missing detection of target. A dynamic programming based pre-detection tracking algorithm for small and weak target detection under low SNR is studied, and the missed detection caused by RCS flicker and sea clutter coverage of the original algorithm is studied. An improved dynamic programming method based on frame extrapolation is proposed. When the k frame is not within the state transition range of the first frame, the state transition from the second frame to the second frame is considered. The effectiveness of the algorithm is analyzed by simulation, which ensures that the final detection result will not be affected when a frame is missed, and improves the operation speed while ensuring the detection probability. Based on pulse compression and digital beamforming process, a practical high-frequency ground wave radar system is designed to suppress sea clutter, coherent accumulation and CFAR detection. A high frequency ground wave radar ship target detection scheme based on tracking before dynamic programming detection is presented. The validity of the detection scheme is verified by comparing the measured data processing results with the AIS information of the ship information network. The method can realize continuous detection and track formation for ships whose captain is about 150m within 90 km.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：E925;TN958.93
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本文编号：1776254