The correlation analysis of sea clutter data in a complex domain is conducted in this study. Specific to X-band sea clutter, the statistical characteristics of the complex correlation, particularly the phase character...The correlation analysis of sea clutter data in a complex domain is conducted in this study. Specific to X-band sea clutter, the statistical characteristics of the complex correlation, particularly the phase characteristics which are closely related to the phase difference of the sea clutter and the Doppler properties, are analyzed in detail based on the experimental data, recorded by the Mc Master University IPIX radar in 1993. That the phase term of the complex correlation presents linear change means that there exists the linearity of phase differences between different time intervals in the X-band sea clutter. This investigation explores the regularities about the effect of wind on the complex correlation with similar patterns for different polarization modes. The regularities indicate that the wind direction can be inferred from the distribution pattern of the complex correlation. Moreover, a model describing the relationships between the statistics of the complex correlation and wind parameters is proposed. The application for target detection based on the differences of characteristics of complex correlations between the sea clutter and the target are also investigated and the proposed features have been confirmed. The principle of the method is fundamental for broader future applications.展开更多
This paper describes a technique to estimate surface-based duct parameters by using a simple ray tracing/correlation method.The approach is novel in that it incorporates the Spearman rank-order correlation scheme betw...This paper describes a technique to estimate surface-based duct parameters by using a simple ray tracing/correlation method.The approach is novel in that it incorporates the Spearman rank-order correlation scheme between the observed surface clutter and the surface ray density for a given propagation path.The simulation results and the real data results both demonstrate the ability of this method to estimate surface-based duct parameters.Compared with the results obtained by a modified genetic algorithm combined with the parabolic wave equation,the results retrieved from the ray tracing/correlation scheme show a minor reduction in accuracy but a great improvement on computation time.Therefore the ray tracing/correlation method might be used as a precursor to more sophisticated and slower techniques,such as genetic algorithm and particle filters,by narrowing the parameter search space and providing a comprehensive and more efficient estimation algorithm.展开更多
This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, whi...This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance "corridor", based on the position (range) correlation information of one-dimensional range images(or called range profiles) of high resolution radar targets. The experimental results, on the real echo data of tank illuminated by the millimeter-wave stepped frequency high resolution radar, have certified that such a method presented in this paper is a very effective detection method for multiple extended targets.展开更多
Conventional scan-to-scan integration correlation (SIC) algorithms can detect small and stationary targets. However, they are ineffective in detecting small and fast-moving targets. This paper presents an improved SIC...Conventional scan-to-scan integration correlation (SIC) algorithms can detect small and stationary targets. However, they are ineffective in detecting small and fast-moving targets. This paper presents an improved SIC algorithm together with clutter suppression measures that remove or decrease sea clutter. The algorithm divides the scan-to-scan integration (SI) into two branches, one provides optimum clutter attenuation by means of SI weighting while the other ensures that targets are detected even if they are fast-moving. Sea clutter suppression can lower detection thre-sholds and, at the same time, increase signal-to-clutter ratio. Simulation results show that the proposed approach greatly improves the detection capability for warship radar.展开更多
在球不变随机向量(SIRV,Spherically Invariant Random Vector)的非高斯杂波背景下,提出了一种新的距离扩展目标检测器.给出了检测参数的简易确定方法,推导了虚警概率与检测阈值的解析表达式,证明了所提检测器的恒虚警率特性.仿真实验表...在球不变随机向量(SIRV,Spherically Invariant Random Vector)的非高斯杂波背景下,提出了一种新的距离扩展目标检测器.给出了检测参数的简易确定方法,推导了虚警概率与检测阈值的解析表达式,证明了所提检测器的恒虚警率特性.仿真实验表明,在参数设置合理情况下,所提出的检测器性能远好于已有的两种距离扩展目标检测器.另外,随着阵元数、目标散射点个数及杂波尖峰的增加,检测器的性能得到提高;且该检测器对第三门限的选取和不同的杂波相关性均具有很好的鲁棒性.展开更多
基金supported by the National Natural Science Foundation of China (61271406)
文摘The correlation analysis of sea clutter data in a complex domain is conducted in this study. Specific to X-band sea clutter, the statistical characteristics of the complex correlation, particularly the phase characteristics which are closely related to the phase difference of the sea clutter and the Doppler properties, are analyzed in detail based on the experimental data, recorded by the Mc Master University IPIX radar in 1993. That the phase term of the complex correlation presents linear change means that there exists the linearity of phase differences between different time intervals in the X-band sea clutter. This investigation explores the regularities about the effect of wind on the complex correlation with similar patterns for different polarization modes. The regularities indicate that the wind direction can be inferred from the distribution pattern of the complex correlation. Moreover, a model describing the relationships between the statistics of the complex correlation and wind parameters is proposed. The application for target detection based on the differences of characteristics of complex correlations between the sea clutter and the target are also investigated and the proposed features have been confirmed. The principle of the method is fundamental for broader future applications.
基金Project supported by the National Natural Science Foundation of China (Grant No. 40775025)
文摘This paper describes a technique to estimate surface-based duct parameters by using a simple ray tracing/correlation method.The approach is novel in that it incorporates the Spearman rank-order correlation scheme between the observed surface clutter and the surface ray density for a given propagation path.The simulation results and the real data results both demonstrate the ability of this method to estimate surface-based duct parameters.Compared with the results obtained by a modified genetic algorithm combined with the parabolic wave equation,the results retrieved from the ray tracing/correlation scheme show a minor reduction in accuracy but a great improvement on computation time.Therefore the ray tracing/correlation method might be used as a precursor to more sophisticated and slower techniques,such as genetic algorithm and particle filters,by narrowing the parameter search space and providing a comprehensive and more efficient estimation algorithm.
文摘This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance "corridor", based on the position (range) correlation information of one-dimensional range images(or called range profiles) of high resolution radar targets. The experimental results, on the real echo data of tank illuminated by the millimeter-wave stepped frequency high resolution radar, have certified that such a method presented in this paper is a very effective detection method for multiple extended targets.
文摘Conventional scan-to-scan integration correlation (SIC) algorithms can detect small and stationary targets. However, they are ineffective in detecting small and fast-moving targets. This paper presents an improved SIC algorithm together with clutter suppression measures that remove or decrease sea clutter. The algorithm divides the scan-to-scan integration (SI) into two branches, one provides optimum clutter attenuation by means of SI weighting while the other ensures that targets are detected even if they are fast-moving. Sea clutter suppression can lower detection thre-sholds and, at the same time, increase signal-to-clutter ratio. Simulation results show that the proposed approach greatly improves the detection capability for warship radar.
文摘在球不变随机向量(SIRV,Spherically Invariant Random Vector)的非高斯杂波背景下,提出了一种新的距离扩展目标检测器.给出了检测参数的简易确定方法,推导了虚警概率与检测阈值的解析表达式,证明了所提检测器的恒虚警率特性.仿真实验表明,在参数设置合理情况下,所提出的检测器性能远好于已有的两种距离扩展目标检测器.另外,随着阵元数、目标散射点个数及杂波尖峰的增加,检测器的性能得到提高;且该检测器对第三门限的选取和不同的杂波相关性均具有很好的鲁棒性.
