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1.
刘延彬  姜媛媛 《激光与红外》2021,51(9):1243-1248
针对2D激光雷达扫描数据异常值检测问题,提出了最邻近距离-局部异常因子检测算法。首先给出2D激光雷达扫描数据孤立点的定义,并依此检测扫描数据的孤立点;其次基于局部异常因子检测扫描数据的局部异常点;最后采用5组实际环境中的2D雷达扫描数据对算法进行验证。研究结果表明:最邻近距离-局部异常因子检测算法能够检测出2D激光雷达扫描数据的异常值,且算法的平均误报率为1228、平均计算时间为0842s,可满足实际需求。  相似文献   

2.
船载某C频段统一测控系统(UCB)因为光轴变化,使得坞内标定的角度零值、光机偏差等轴系误差修正参数不能准确校正设备的光轴指向偏差,而以光轴为基准放球标定的光电偏差修正参数无法使用。针对这个难题,在深入分析雷达轴系误差修正原理及参数标定方法的基础上,提出了基于测星数据动态标定雷达轴系误差参数、基于脉冲雷达电轴推算UCB光电偏差参数的替代方法,给出了相关数学模型,并利用实测数据进行了验算分析。试验结果表明,替代方法标定的参数准确合理,误差修正精度高,有效提升了数据处理精度。  相似文献   

3.
研究机载设备异常数据的判别及修正问题, 提出了改进多项式外推拟合算法, 并在FPGA中对GPS和AHRS数据中的异常值进行判别和修正。根据机载数据的统计特性计算各物理量的标准差, 对多项式外推拟合算法进行改进, 简化了乘除法运算的硬件实现方式, 使之适合并行工作方式的FPGA进行异常值快速判断和处理。飞行试验数据处理结果表明, 该方法能够有效地判别、修正异常值, 满足飞行试验要求。  相似文献   

4.
提出了一种浅层探地雷达快速异常区域检测方法.通过数字图像处理技术对探地雷达探测数据进行分析处理,根据地表回波梯度幅度大的图像特性将其从雷达数据中去除以克服其对地下异常目标检测的影响,然后利用基于梯度的自适应阈值方法在抑制杂波干扰的同时,对地下层中的异常区域进行快速定位.通过实测数据的实验验证,证实了所提的方法在处理异常目标检测与定位时的高效与快速.  相似文献   

5.
基于半参数化概率密度估计的雷达目标识别   总被引:2,自引:1,他引:1  
该文针对雷达目标高分辨距离像(High-Resolution Range Profile, HRRP)识别中距离单元回波幅值统计建模所面临的概率密度模型选择问题,提出一种基于半参数化概率密度估计的雷达目标识别方法。半参数化概率密度估计从参数化概率密度估计出发,有效利用了高分辨距离像各距离单元幅值近似服从Gamma分布的经验知识,并且通过非参数化修正因子对Gamma模型进行修正,达到参数化方法和非参数化方法优缺互补的目的。基于5种飞机模型高分辨距离像数据的仿真实验证明了该文方法的有效性。  相似文献   

6.
对截获的雷达信号进行准确的分析和处理,实现对特定目标的异常特征信息进行快速发现、分析和挖掘,在提高雷达信号数据质量、发现入侵行为、进行故障诊断以及辅助军事侦察等领域都具有非常重要的意义。结合雷达信号的异常流行为,利用距离与聚类的统计思想,提出了一种针对雷达信号5个电子脉冲参数的复合分层分析异常挖掘方法,并运用5部仿真雷达的模拟数据进行了验证,发现该方法可对信度较高。  相似文献   

7.
《无线电工程》2018,(3):235-239
针对船载雷达方位零位标定过程复杂,故障排查难度大的问题,在简要介绍船载雷达方位零位标定方法的基础上,分析了导致船载雷达方位零位异常变化的可能原因,提出了对船载雷达方位零位异常变化问题的分析及排查通用流程。结合实际典型案例,对由经纬仪轴系变化和全船方位基准不统一导致的船载雷达方位零位异常变化的问题进行了深入研究,并从不同角度分析了对测量精度的影响。提出的通用流程对指导复杂的船载雷达误差修正参数的标定和提高船载雷达测量精度具有重要的实用价值。  相似文献   

8.
针对动态条件下船载雷达误差修正参数标定困难的问题,提出了基于星敏感器的船载雷达误差修正参数解算方法,该方法以安装于船载雷达天线的星敏感器测角数据为比对基准。总结了船载雷达标定方法的现状,介绍了基于星敏感器的船载雷达误差修正参数解算原理,推导了船载雷达误差计算公式和误差修正参数解算模型。通过计算雷达相对星敏感器的角度残差,采用最小二乘算法实现了误差修正参数的解算。最后,通过静态与动态试验对该方法进行了验证。试验结果表明,静态条件下,该方法与传统坞内标定结果相比一致性优于15″,动态条件下的一致性优于25″,说明该方法技术上是可行的。  相似文献   

9.
杨峰  刘胜强 《电子设计工程》2022,30(3):113-116,121
针对传统聚类算法对于大数据背景下大量电力大数据异常监测过程中存在的问题,提出在电力大数据异常值检测中的快速密度峰值聚类算法的改进.对传统基于密度峰值空间聚类方法进行分析,得到传统算法在使用过程中的问题.提出了快速密度峰值聚类算法的改进,对自适应参数与聚类中心自动的选择,通过标准化局部密度与距离对大数据异常值进行评测,能...  相似文献   

10.
为了解决步进频连续波雷达中的强目标距离旁瓣掩盖弱小目标问题,对步进频自适应脉压算法( SFCW-RMSMIL)进行修正,并联合修正SFCW-RMSMIL算法和CLEAN技术,提出了一种新的自适应CLEAN算法( A-CLEAN)。该算法解决了弱小目标能量严重压制问题,同时还能精确估计各目标的幅度和位置,提高了雷达对弱小目标的检测能力。最后利用仿真数据、实测数据以及蒙特卡洛实验验证了新提出的A-CLEAN算法的有效性和实用性。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

18.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

20.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

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