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1.
Pareto分布是一种重要的非高斯分布,被证明能够有效描述高分辨率主动声纳的混响统计特性。文章分析了有序统计选小(Ordered Statistic with Smallest Option, OSSO)和有序统计选大(Ordered Statistic with Greatest Option, OSGO)两种恒虚警(Constant Fales Alarm Rate, CFAR)检测器在Pareto分布混响背景下的性能。在尺度参数已知情况下,证明了OSSO-CFAR和OSGO-CFAR对形状参数具有恒虚警的特性。进一步分析了两种检测器在均匀Pareto混响背景、多目标干扰及混响边缘情况下的性能,并与有序统计(Ordered Statistic, OS)CFAR进行了对比。结果表明,在均匀混响背景下,OSGO-CFAR的检测性能与OS-CFAR相近,在混响边缘情况下具有最好的虚警控制能力;而对于多目标干扰情况,OSSO-CFAR比其他两种检测器的检测性能更优。 相似文献
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OSGO-和OSSO-CFAR在K分布杂波背景下的性能分析 总被引:5,自引:1,他引:4
该文证明了形状因子已知条件下OSGO-CFAR和OSSO-CFAR检测器在均匀统计独立的K分布杂波背景下具有恒虚警性能,分析了两种检测器在均匀杂波背景、杂波边缘和存在强干扰目标情况下的检测性能。并与OS-CFAR进行了比较,结果表明OSGO-CFAR在均匀杂波背景和存在强干扰目标情况下带来的附加检测损失很小, 在杂波边缘具有更好的虚警控制能力。所以,OSGO-CFAR是K分布杂波背景下一种性能比较好的恒虚警检测器。 相似文献
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In this paper, we propose to analyze the binary integration of the cell-averaging constant false-alarm rate (CA-CFAR) and
order statistics constant false-alarm rate (OS-CFAR) detectors in the presence of non-Gaussian spiky clutter modeled as a
Pearson distribution. We derive new closed form expressions for false alarm and detection probabilities for the CA-CFAR detector
in the presence of Pearson-distributed clutter backgrounds. We first show that the use of binary integration improves the
detection probabilities of the detectors considered. Secondly, the maximum of detection probability occurs for an optimum
choice when the second threshold is set to be equal to M = (3/4) L. For this optimum M-out-of-L rule, the comparison analysis of the CA-CFAR and OS-CFAR binary integrators showed that the latter has better performance
in homogeneous Pearson- distributed clutter. 相似文献
4.
The use of genetic algorithms (GAs) tool for the solution of distributed constant false alarm rate (CFAR) detection for Weibull
clutter statistics is considered. An approximate expression of the probability of detection (P
D) of the ordered statistics CFAR (OS-CFAR) detector in Weibull clutter is derived. Optimal threshold values of distributed
maximum likelihood CFAR (ML-CFAR) detectors and distributed OS-CFAR detectors with a known shape parameter of the background
statistics are obtained using GA tool. For the distributed ML-CFAR detection, we consider also the case when the shape parameter
is unknown of the Weibull distribution. A performance assessment is carried out, and the results are compared and given as
a function of the shape parameter and of system parameters. 相似文献
5.
MohamedB EMashade 《电子科学学刊(英文版)》2004,21(4):265-277
This paper deals with the exact detection analysis of the Ordered-Statistic(OS) processor along with OS Greatest Of(OSGO) and OS Smallest Of(OSSO) modified versions, for Mpostdetection integrated pulses when the operating environment is nonhomogeneous. Analytical results are presented in multiple-target case as well as in regions of clutter power‘transitions. The primary and the secondary interfering targets are assumed to be fluctuating in accordance with the SWII target fluctuation model. As the number of noncoherently integrated pulses increases,lower threshold values and consequently better detection performances are obtained in both homogeneous and multiple target background models. However, the false alarm rate performance of OSSO-CFAR(Constant False Alarm Rate) scheme at clutter edges is worsen with increasing the postdetection integrated pulses. As predicted, the OSGO-CFAR detector accommodates the presence of spurious targets in the reference window, given that their number is within its allowable range in each local window, and controls the rate of false alarm when the contents of the reference cells have clutter boundaries. 相似文献
6.
一种K-分布杂波背景下的双参数恒虚警检测器 总被引:2,自引:1,他引:1
该文基于改进的M-估计器和OSGO-CFAR检测器,提出了K-分布杂波背景下一种新的双参数恒虚警检测器,然后在均匀干扰背景中研究了这种检测器的性能,并与固定形状参数的OSGO-CFAR检测器进行了比较。结果表明,具有形状参数估计的OSGO相对于理想固定形状参数OSGO只带来很小的附加损失,同时具有更广泛的K-分布杂波适应性。 相似文献
7.
Xiangwei Meng 《AEUE-International Journal of Electronics and Communications》2013,67(7):611-615
In order to improve the detection performance of Nitzberg's clutter map in a more spiky clutter environment, a new clutter map detection scheme which combines binary integration with the classic clutter map is proposed and analyzed. It's shown that the detection performance of the clutter map with binary integration is greatly improved compared to the classic clutter map with a single pulse processing. 相似文献
8.
有序统计恒虚警(OS-CFAR)检测器在韦布尔干扰背景中的性能 总被引:1,自引:0,他引:1
本文研究韦布尔干扰背景前的有序统计恒虚警算法,并在均匀干扰背景中分析它的性能,对于未知的形状参数C,本文基于来自参考滑窗随机变量的期望和中值提出一种估计方法,同时在均匀干扰背景中研究了这种估计方法的性能,结果表明,这种估计方案具有很小的附加恒虚警损失,当N=16,C=2,k=12时,它的恒虚警损失比两参数有序统计恒虚警检测器小.. 相似文献
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在G0分布背景杂波假设下,基于VI-CFAR算法该文提出一种自动区域筛选的恒虚警目标检测算法,以解决高分辨SAR图像复杂环境背景下的目标检测问题。该算法首先利用变化指数(VI)统计量对局部参考窗内的均匀区域进行筛选,以剔除参考窗内具有目标干扰点的非均匀区域;然后利用均值比(MR)统计量对参考窗内同质的均匀区域进行区域合并,以解决杂波边界处的背景杂波筛选问题;最后利用筛选到的同质均匀区域内的像素集合进行背景杂波参数估计,对待检测区域实现二值检测。通过实测SAR图像车辆目标检测实验表明,在多目标和杂波边界复杂环境背景下,该算法具有较稳定的检测性能和虚警抑制能力。 相似文献
11.
相参雷达系统下的非相干积累检测方法,可以提高雷达的目标检测速度,达到实时处理的要求。然而,相参雷达系统下的非相干积累检测方法对参考单元数、脉冲积累数、杂波散斑协方差矩阵以及海杂波模型的形状参数均是非恒虚警(CFAR)的。该文基于块白化的海杂波预白化方法,提出预白化单元平均恒虚警(PWCA-CFAR)检测方法和预白化单元中值恒虚警(PWCM-CFAR)检测方法,并使用了匹配于参考单元数、脉冲积累数、形状参数的自适应门限,确保提出检测方法的恒虚警特性。实验结果表明,当存在异常单元时,PWCM-CFAR检测方法的检测性能优于PWCA-CFAR检测方法。 相似文献
12.
《AEUE-International Journal of Electronics and Communications》2014,68(12):1253-1260
In radar detection, many constant false alarm rate (CFAR) processors have been proposed in the literature. It is well known that a processor is optimal only for one type of environment and that its detection performances are seriously degraded in presence of unknown irregularities. In such situations, the main difficulty resides in the estimation of the background configuration. That is, depending upon the non-homogeneity of the environment, one would choose the adequate optimal detection algorithm among a variety of known conventional ones that offer the best detection probability. Based on unknown transitions; i.e., in the presence of a priori unknown numbers of interfering targets and/or clutter edge, we propose an automatic censoring CFAR (AC-CFAR) detector for heterogeneous Gaussian clutter. The censoring technique used in this work offers a good discrimination between homogeneous and non-homogeneous environments. The proposed detector dynamically switches to the optimal conventional detector CA-, CMLD- or TM-CFAR. The performances of the proposed detector is evaluated and compared to existing detectors in various background situations. Monte Carlo simulations show that the AC-CFAR detector performs like the CA-CFAR in a homogeneous background. Moreover, the proposed detector exhibits considerable robustness in the presence of interfering targets and/or clutter-edge situations. 相似文献
13.
本文证明了形状因子已知条件下有序统计平均(OSCA)恒虚警检测器在K分布杂波背景下具有恒虚警性能,分析了均匀K分布杂波背景和多目标情况下该检测器的性能,并与OS和OSGO-CFAR进行了比较,仿真结果表明OSCA在两种环境下均具有最好的检测性能。 相似文献
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为确保能够在海杂波背景中检测小目标,必须采取有效的杂波抑制方法。文中首先通过理论分析和实测数据验证,分析海杂波对检测虚警率的影响,研究分析表明若采用特定门限系数,不同海况下的虚警分布有非常大的差别。在前述分析的基础上,本文对扫描间积累的效果进行了仿真和实测数据验证,比较了不同二进制积累逻辑下的杂波抑制效能。仿真和测试结果均表明扫描间积累可实现虚警率的有效控制,而且随着积累时间的增加,杂波抑制效果更为理想。 相似文献
17.
单元筛选后作最小选择的CFAR自适应检测器 总被引:1,自引:0,他引:1
为提高雷达自适应检测能力,本文针对多个干扰目标背景提出一种新的CFAR自适应检测方法。在斯威林2型目标的假设下对这种检测方法进行了检测性能分析,理论推导出均匀杂波背景和强干扰目标存在的情况下虚警概率和检测概率的数学模型,并把它同CA、GO、SO(smallest of)等检测方法用MATLAB仿真软件进行了比较。结果表明,这种方法在均匀杂波背景和多个干扰目标背景情况下都有很好的检测性能,尤其是多目标干扰条件下具有更大的优势。 相似文献
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Mohamed B. El Mashade 《Radioelectronics and Communications Systems》2018,61(9):377-393
Modern radars have adopted adaptive processing techniques to mitigate the deleterious effects of unwanted clutter and jammer. In this situation, the CFAR algorithms play a vital role in achieving the heterogeneous detection of fluctuating targets. In this regard, while the CA-CFAR processor has the top homogeneous performance, the OS and TM techniques have been suggested to provide robust estimates of the threshold in heterogeneous situations. In order to simultaneously exploit the merits of CA and OS or TM processors, some their hybrid versions have been recently introduced. They are termed as CAOS and CATM models. Practically, the frequency diversity between noncoherent sweeps is widespread in actual radar systems. Additionally, the pulse integration strategy is often used in radar systems to improve the target signal-to-noise ratio and correspondingly the system detection performance. For this reason, this paper is focusing on analyzing these new models in the case where the radar receiver noncoherently integrates M-pulses to handle its detection. Closed-form expression is derived for their nonhomogeneous performance. The tested as well as the spurious targets are assumed to follow χ2-distribution with four degrees of freedom in their fluctuations. Our simulation results reveal that the new version CATM exhibits a homogeneous performance that outweighs that of the classical Neyman-Pearson (N-P) procedure, which is employed as a baseline comparison for other strategies in the field of adaptive detectors. 相似文献
20.
MOSCA-CFAR检测器在干扰边缘中的性能分析 总被引:1,自引:0,他引:1
本文研究MOSCA-CFAR检测器[1]在干扰边缘中的性能。文中推导出了背景噪声和杂波为高斯分布条件下,它在干扰边缘环境中虚警概率的解析表达式,分析了它抗干扰的性能,并且与OS、CA、SO和GOSCA等检测器进行了比较.结果表明,MOSCA在获得在均匀背景和多目标环境中的良好检测性能的同时也保持了较好的抗边缘干扰性能. 相似文献