高频地波雷达目标二维CFAR检测及软件实现

发布时间：2018-07-11 15:06

本文选题：高频地波雷达 + CFAR处理　；参考：《中国海洋大学》2014年硕士论文

【摘要】：高频地波雷达利用高频电磁波在海面绕射传播的特性，能够超视距探测到海平面以下的船只目标和低空飞机。鉴于地波雷达的目标探测性能，全球越来越多的国家大力发展高频地波雷达用来监测远距离海面船只目标。其中，雷达目标检测是雷达回波信号处理的关键步骤之一，目标检测算法得到越来越多科研人员的关注，其中恒虚警目标检测算法是目标检测算法中的研究热点之一。地波雷达目标CFAR检测是地波雷达目标检测的重要环节，其探测性能直接影响目标检测及后续跟踪的探测性能。根据目标在距离-多普勒谱中的扩展性，目标二维CFAR检测能更好的对噪声背景进行估计，在本文中，主要基于目标二维CFAR检测展开探讨：在地波雷达目标二维CFAR探测方法研究方面，首先，介绍了基于曲线拟合的目标一维CFAR检测的原理和处理流程，针对船只目标的运动性，由一维CFAR检测扩展到二维CFAR检测。高频地波雷达对运动目标比较敏感，目标在RD谱上的扩展性，采用二维参考窗能更准确的估算目标背景噪声，提高目标检测性能。根据目标在距离向和多普勒向扩展的理论分析，并结合对大量实测数据的统计，给出二维参考窗的参考单元、保护单元等参数的选取原则。用地波雷达实测数据对比分析一维CFAR检测和二维CFAR检测效果，验证了目标二维CFAR检测方法能够提高目标检测的性能。在CFAR处理方面，根据海杂波和地杂波在距离-多普勒谱上的对称分布特征，把基于整体曲线拟合的CFAR处理方法发展到基于分段曲线拟合的CFAR处理方法。介绍基于分段曲线拟合的目标二维CFAR检测方法的原理和实现步骤，分析了基于分段曲线拟合和整体曲线拟合CFAR处理的区别。利用实测数据对比了两种CFAR处理算法的效果，并且利用同步AIS数据，验证和评价了目标检测。结果表明基于分段曲线拟合的二维CFAR检测效果要好于基于整体曲线拟合的二维CFAR检测效果，特别是对海杂波内侧的弱目标信号探测效果明显。最后，基于Matlab平台开发高频地波雷达目标CFAR检测软件系统。该软件中集成了已实现的CFAR处理算法。能够对于选择的处理算法，，修改相应的参数，并显示雷达相应的参数。实时显示处理数据的目标检测结果和多普勒谱。软件实现AIS读取功能，把AIS数据的格式转换到距离-多普勒谱的格式，并能根据需要进行显示，方便和雷达目标检测的对比。
[Abstract]:High frequency ground wave radar can detect ship targets and low altitude aircraft below sea level by using the characteristics of high frequency electromagnetic wave diffraction at sea level. In view of the target detection performance of ground-wave radar, more and more countries around the world develop high-frequency ground-wave radar to monitor ship targets over long distances. Among them, radar target detection is one of the key steps of radar echo signal processing, and target detection algorithm has been paid more and more attention by researchers, among which CFAR target detection algorithm is one of the research hotspots in target detection algorithm. CFAR detection of ground wave radar targets is an important part of ground wave radar target detection. Its detection performance directly affects the detection performance of target detection and subsequent tracking. According to the expansibility of target in range-Doppler spectrum, the target 2-D CFAR detection can better estimate the noise background. In this paper, Mainly based on the target two-dimensional CFAR detection development: in the ground wave radar target two-dimensional CFAR detection method research aspect, first, introduced the target one-dimensional CFAR detection principle and the processing flow based on the curve fitting. Aiming at the movability of ship targets, one dimensional CFAR detection is extended to two dimensional CFAR detection. High frequency ground wave radar is sensitive to moving targets and the target is extensible in Rd spectrum. Using two-dimensional reference window can more accurately estimate the background noise of the target and improve the performance of target detection. Based on the theoretical analysis of target expansion in the range and Doppler directions and the statistics of a large number of measured data, the selection principles of parameters such as the reference unit and the protection unit of the two-dimensional reference window are given. The results of one-dimensional CFAR detection and two-dimensional CFAR detection are compared and analyzed. The results show that the target two-dimensional CFAR detection method can improve the performance of target detection. In the aspect of CFAR processing, according to the symmetrical distribution of sea clutter and ground clutter in range-Doppler spectrum, the CFAR processing method based on integral curve fitting is developed to CFAR processing method based on piecewise curve fitting. This paper introduces the principle and implementation steps of the target 2D CFAR detection method based on piecewise curve fitting, and analyzes the difference between the CFAR processing based on piecewise curve fitting and integral curve fitting. The effect of two CFAR processing algorithms is compared with the measured data, and the target detection is verified and evaluated by synchronous AIS data. The results show that the detection effect of two-dimensional CFAR based on piecewise curve fitting is better than that of two-dimensional CFAR based on integral curve fitting, especially for weak target signals inside sea clutter. Finally, the software system of CFAR detection for HF ground wave radar is developed based on Matlab platform. The implemented CFAR processing algorithm is integrated in the software. For the selected processing algorithm, the parameters can be modified and the radar parameters can be displayed. Real-time display of target detection results and Doppler spectrum of processed data. The software realizes the reading function of AIS, converts the format of AIS data to the format of range-Doppler spectrum, and can display it according to the need, which is convenient to compare with radar target detection.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.52

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