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1.
单机无源定位跟踪技术具有隐蔽性强、设备简单以及系统相对独立等优点,有着广阔的应用前景.为了提高定位精度和收敛速度,在现有的基于EKF单机无源定位算法的基础上,推导了基于MGEKF的定位算法,以解决EKF算法的不稳定性和对滤波初始值要求高的问题.与EKF定位算法相比,MGEKF定位算法对滤波初始值的要求相对较低,MGEKF定位算法提高了定位精度、收敛速度和稳定度,定位结果能够满足实际需求.  相似文献   

2.
针对外辐射源无源定位系统实现快速和高精度定位的要求,提出了一种在测量到达角及时差信息的基础上,增加方位角变化率信息的单站无源定位算法。同时引入一种对非线性系统较好的滤波算法——修正增益扩展卡尔曼滤波(MGEKF)算法,与推广卡尔曼滤波器(EKF)相比,MGEKF能更好地解决量测模型非线性问题,滤波性能更好。计算机仿真结果也表明了此定位方法具有较好的定位跟踪精度和速度。  相似文献   

3.
利用频率变化率、方位角及俯仰角信息,提出一种对固定辐射源的三维单站无源定位算法。该方法通过质点运动学原理,得出目标辐射源的位置,之后采用EPF滤波算法进行处理,对粗略定位结果进行修正和平滑,逐步估计出目标的位置。EPF(ExtendedParticleFilter)滤波是将EKF(ExtendedKalmanFilter)算法作为重要性函数的一种粒子滤波方法。仿真结果表明,基于EPF滤波的单站无源定位算法比传统的EKF滤波算法收敛更快、更稳定,滤波效果更好,定位精度更高,这对无源定位跟踪算法精度的提高和实际应用有很大的意义。  相似文献   

4.
基于单站无源定位技术研究基础,对相位差变化率定位原理进行了简要介绍,针对相位差变化率定位过程中相位模糊、定位时间长和定位精度低等问题,提出了一种基于MGEKF滤波算法的相位差变化率单站无源定位方法,该方法采用了相位差参数预处理和MGEKF定位滤波算法。经过仿真分析和外场试验验证表明:采用MGEKF定位滤波处理的相位差变化率无源定位方法,可以使单站定位速度和定位精度比传统的只测角定位法提高很多。  相似文献   

5.
王鼎 《电子对抗》2007,(6):24-27,33
联合角度(DOA)信息和时差(TDOA)信息对运动目标进行多站无源定位实质上是一种非线性估计问题。文章基于DOA和TDOA信息,提出了二种多站对三维空间目标进行定位跟踪的修正增益扩展卡尔曼滤波(MGEKF)算法,文中分别推导了角度观测方程和时差观测方程的修正增益函数。计算机仿真表明该算法的定位精度和稳健性能均要高于扩展卡尔曼滤波(EKF)算法。  相似文献   

6.
基于多级网格搜索的固定单站无源定位方法   总被引:3,自引:0,他引:3  
针对扩展卡尔曼(EKF)类递推方法用于固定单站无源定位时存在依赖于初始值和不稳定性等缺点,本文提出了一种利用角度和频率变化率无源跟踪的网格搜索方法,只要网格取得足够密,最终估计趋近于全局最优的最小均方估计(MMSE).为了减少搜索的计算量,提出了利用多级搜索法将计算量控制在合理可实现的范围.仿真表明,该方法的滤波不受状态初值误差的影响,滤波收敛速度接近无初值误差时的EKF、修正协方差扩展卡尔曼滤波(MVFKF)方法.  相似文献   

7.
纯方位被动目标运动分析的修正增益卡尔曼滤波算法研究   总被引:4,自引:3,他引:1  
通过对滤波状态协方差估计的修改,将水下纯方位被动目标运动分析中的扩展卡尔曼滤波(EKF)算法改进为修正增益扩展卡尔曼滤波(MGEKF)算法,并指出了两者的联系与区别。对比仿真分析表明,MGEKF较之EKF滤波效果有所改善,增强了稳定性,提高了精度,为水下纯方位被动目标运动分析的实现提供新的途径。  相似文献   

8.
针对基于外辐射源的固定单站无源定位问题,给出了一种对运动目标进行定位跟踪的改进型滤波算法。文中首先建立目标角度信息、直达波与散射波的时间差信息以及多普勒频移信息的观测方程,并推导了每个观测方程的修正增益函数,然后利用多个时刻的观测值扩充了观测方程,从而给出了一种基于扩充观测方程的修正增益扩展卡尔曼滤波(MGEKF)算法。经过计算机仿真验证,该算法可以提高定位精度,并能有效地抑制滤波发散。  相似文献   

9.
单站无源定位原理浅析   总被引:1,自引:0,他引:1  
祝咏晨 《信息技术》2006,30(8):84-85
探讨了一种基于目标频域和空域参数测量信息,利用固定单站对机动目标进行无源定位与跟踪的算法,并详细分析了定位原理。在建立目标机动模型与测量方程的基础上,运用修正增益的扩展卡尔曼滤波(MGEKF)算法,实现对机动目标进行定位与跟踪。  相似文献   

10.
固定单站对三维运动辐射源无源定位算法及可观测性分析   总被引:22,自引:0,他引:22  
实现固定单站对运动辐射源无源定位,传统的方法是测量TOA和DOA。本文将方位角变化率测量信息也引入该定位问题,提出了基于MGEKF(修正增益扩展卡尔曼滤波),对三维运动辐射源的无源定位跟踪算法。通过推导伪线性测量方程,本文进行了测量TOA和DOA对三维运动目标无源定位的可观测性分析。最后给出了计算机仿真结果。  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.
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   

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.
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   

15.
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   

16.
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   

17.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

18.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

19.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

20.
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   

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