共查询到19条相似文献,搜索用时 156 毫秒
1.
2.
3.
4.
5.
6.
基于形态学梯度的红外目标检测 总被引:1,自引:0,他引:1
对于红外跟踪系统中的低空非合作运动目标检测问题,由于距离未知,目标可能表现为小目标或者面目标,另外,红外图像中可能包含大量的地物背景.针对以上问题,本文提出了一种基于形态学梯度的目标检测算法.此方法首先计算红外图像的形态学梯度,进而根据各种地物背景的形态学梯度特征提取天空区域,然后在此区域内进行目标检测,最后进行目标边缘片段的合并.该方法基于形态学梯度对于灰度变化的敏感性,使用形态学梯度来表征红外目标边缘强度,通过检测目标边缘来达到检测目标的目的.实验证明,本文方法能够有效的检测目标,虚警较少,且对小目标和面目标具有一定通用性. 相似文献
7.
8.
针对在水下存在多途、混响及噪声边缘等非平稳背景条件下主动声呐检测器的检测性能,给出了一种变异指数的恒虚警率(Variability Index Constant False Alarm Rate,VI-CFAR)检测器。VI-CFAR结合了单元平均恒虚警率、最大选择恒虚警率和最小选择恒虚警率的检测算法,它在均匀平稳环境和非平稳环境下都具有较强的自适应性。理论分析和仿真结果表明,该检测器在均匀平稳背景下的检测性能与单元平均恒虚警率检测器相似,在多途、混响等干扰背景条件下具有较强的抗干扰能力,在噪声边缘背景下有较好的虚警概率控制能力且运算量小,是一种稳健的检测器。 相似文献
9.
《振动与冲击》2017,(11)
鲸类联络叫声的频段与舰船辐射噪声频段的重叠,使其易被误检测为舰船噪声而被被动声纳接收,影响后续对被动声纳检测到的信号进行目标自主识别等信号处理的性能。针对鲸类联络叫声干扰目标识别等声纳信号后续处理的问题,提出舰船辐射噪声中鲸类联络叫声检测算法,为削除鲸类联络叫声干扰作准备,算法首先通过理论与实测数据分析得出舰船辐射噪声频谱分布的短时稳定性特征,进而采用中值滤波方法对舰船辐射噪声进行白化处理,利用三阶多项式相位信号对鲸类叫声建模,然后通过基于匹配滤波器的广义似然比检测方法,实现了舰船辐射噪声中鲸类信号的检测。经实测信号的实验验证,提出的算法适用于不同类型和工况的舰船;通过与其他三种检测方法的比较分析,算法在给定虚警率下可以取得较高的鲸类叫声检测率,检测结果优于其他三种方法。 相似文献
10.
11.
针对管道泄漏检测系统存在一定误报率的问题,提出一种基于归一化小波能量系数的油气管道安全识别算法.首先提出最佳母小波选择标准,以现场数据为基础选取最佳母小波,然后提取归一化小波能量系数的最大值作为特征量,最后利用Fisher分类器对压力数据进行识别,判断管道是否处于安全状况.利用现场数据对该方法进行验证分析,结果表明该算法识别正确率较高,实用性好,且可以降低误报率. 相似文献
12.
13.
A Detection Theoretic approach to Modeling Aviation Security Problems using the Knapsack Problem 总被引:1,自引:0,他引:1
Designers, operators and users of multiple-device, access-control security systems are challenged by the false alarm, false clear tradeoff. Given a particular access control security system, and a prescribed false clear standard, there is an optimal (minimal) false alarm rate that can be achieved. The objective of this research is to develop a new methodology for determining this false alarm rate. A static grid estimation procedure is used to estimate the joint conditional probability density functions for the security device responses. The concept of a system response function is introduced and the problem of determining a system response function that minimizes the false alarm rate, while meeting the false clear standard, is formulated as a decision problem and proven to be NP-complete. A Greedy Algorithm and a Dynamic Programming algorithm are presented to address this problem. Computational results using simulated security data are reported. These results are compared to analytical results obtained for a pre-specified system response function form. Directions for future research are also discussed 相似文献
14.
针对声呐小目标检测由于水下环境复杂、目标回波信号弱等因素造成虚警率和误检率较高的问题,文章提出基于背景抑制和改进直线分割检测(Line Segment Detection, LSD)的检测算法。首先对原始声呐数据截取序列片段,构建多周期累积历程图,凸显运动目标轨迹线特征;其次设计边缘滤波算子,有效滤除部分背景噪声,并结合投影变换进行线特征增强,不仅实现了断裂直线重连,还抑制了剩余噪声;然后基于图像金字塔改进了多尺度LSD直线分割检测算法,有效缓解了过检测问题,大幅增加了直线平均长度;最后为了合并冗余检测信息,利用运动轨迹时空一致性特征设计后处理模块,提高了检测定位精度。通过多组无人遥控潜水器(Remotely Operated Vehicle, ROV)、潜水员、空心球靶小目标序列的湖试、海试数据的定量与可视化结果定性分析,实验结果显示,文中算法与传统LSD相比,误检率和漏检率分别降低了11.2和3.9个百分点,定位误差下降了1.495个像素。结果表明,文中所提算法大幅提高了声呐小目标检测精度,为后续水下目标识别、跟踪等任务奠定重要基础。 相似文献
15.
采用小波变换的周界报警信号辨识 总被引:1,自引:1,他引:0
马赫-泽德干涉仪结构的光纤传感器应用于周界报警器系统,能够对发生在传感器区域内的振动信号进行报警,并具有极高的灵敏度。为了减少周界报警系统的误报警率,针对周界报警系统输出信号的处理问题,采用小波变换的方法对周界报警系统输出的电压信号进行辨识,不但能滤除信号中的噪声,而且能很好的保留信号的突变部分,可以很好的区分蓄意入侵与风雨产生的振动,从而减少系统误报警率并能实现对蓄意入侵定位,这对于周界报警器系统真正实现工程应用具有突破性进展。大量实验结果表明,采用小波变换方法辨识周界报警系统输出信号,能很好的体现测量信号中的奇异值并显著减少周界报警系统的误报警率。 相似文献
16.
17.
18.
Built-in tests (BITs) are widely used in manufacturing and production systems to find whether system failures occur, whereas the problem of BIT false alarms caused by intermittent failures adds to much trouble for the precise failure detection and diagnosis. Fighting with false alarms caused by intermittent failures is an urgent issue. However, the nature and temporal regularity of intermittent failures are not fully exploited, as well as the relationship between intermittent failure and BIT false alarms. The present paper introduces the method of constructing failure test profile for false alarm assessments. Probabilistic models are proposed of the failure evolution process, as well as the interactions between intermittent failures and false alarms. The false alarm time expectation is derived with the given model, serving as the foundation for the optimisation problem to find the best test threshold to enable the highest BIT capability. A numerical analysis is made to illustrate the proposed model and examine the threshold determination method. An application study is also carried out to show how the model can be applicable in real engineering practices. 相似文献
19.
The performance of the ordered-statistic greatest of (OSGO) constant false alarm rate (CFAR) scheme with binary integration for M non-coherent sweeps in Weibull background was investigated for homogeneous and non-homogeneous backgrounds, with an assumption of known shape parameter. This kind of processing is based on the fact that the clutter can be segmented in regions in many real radar scenarios where a timevarying two-parameter distribution function family can be fitted, but the clutter power may vary locally inside the region. Under the assumption of known shape parameter, the authors examined the changes of the false alarm rate and detection probability of the OSGO-CFAR with binary integration when the shape parameter differs from the nominal one, and compared them to those of the OSGO-CFAR with single pulse processing. The authors have derived analytic expressions of the detection probability and false alarm rate during clutter power transitions for the OSGO-CFAR with binary integration in Weibull background. It is shown that the OSGO-CFAR with binary integration can not only improve the detection performance significantly, but it also control the rise of the false alarm rate at clutter edges more effectively compared to the OSGO-CFAR with single pulse processing. Moreover, it exhibits a good immunity to the variation of the shape parameter. 相似文献