共查询到19条相似文献,搜索用时 636 毫秒
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为了获得高精度的高程信息,干涉SAR系统需要采用长基线结构,进而要求对长基线进行高精度的动态测量。该文针对单相机和激光测距仪组合基线测量系统,提出了一种新的基于距离约束的基线联合动态解算方法。该方法通过对空间后方交会模型增加距离约束条件,实现了对双天线干涉基线的高精度测量。论文对该方法进行了原理性分析和地面实验验证,该方法在约50 m的摄影距离处基线长度测量精度优于1 mm,姿态角精度优于60, 实验结果验证了该方法的有效性和可行性。 相似文献
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回顾了中国科学院电子学研究所重复飞行机载L—SAR干涉系统和机载X波段双天线干涉SAR系统的研制和试验,阐述了利用收发天线分置结构拓展干涉基线长度的方法。在采用三天线的收发天线分置结构机载干涉SAR的基础上,构建三天线的双基线机载干涉SAR,并就其基线精密动态测量和基线优化设计两个关键技术以及系统性能进行了分析。分析结果表明,利用三天线构成的双基线机载干涉SAR是改进相位展开过程、提高高程测量精度的有效方法。 相似文献
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GPS姿态测量的精度主要受到卫星几何分布,基线几何关系和多路径效应的影响,本文分析了影响姿态测量的几种误差,并且给出了推算精度的算法,最后,通过动态试验度量了基线长度和天线几何分布对姿态测量精度的影响。 相似文献
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该文针对姿态测量过程中求解整周模糊度计算复杂度高的问题,提出一种基于天线布局的姿态测量方法。该方法在一定的测量误差下,采用特定的方式配置姿态测量天线组,通过天线配置的约束信息确定载波相位的整周模糊度差,并使用短基线和中基线分别进行姿态粗测和精测,达到快速姿态测量和提高精度的目的。使用这种方法进行飞行器姿态测量时可以不必求解整周模糊度,避免了复杂的整周模糊度搜索算法,进而提高了姿态测量速度,该方法非常适用于飞行器的快速测姿。 相似文献
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一种使用双棱镜的动态小角度测量方法 总被引:1,自引:1,他引:1
提出一种基于正切关系和相位调制技术的动态小角度测量方法.使用双棱镜组成干涉测量臂引导两束平行光至分束棱镜处干涉,通过提取携带被测信息的干涉信号的相位实现动态的小角度测量.由于采用位置探测器(PSD)对测量臂中两平行光束的间距进行测量,简化了测量方程,消除了装置中双棱镜必须对称放置的要求.通过正弦地改变半导体激光器的注入电流在时域内实现对干涉信号的相位调制,形成准外差干涉测量模式,提高了光程差的测量精度.实验验证了该方法的可行性,并讨论了影响小角度测量精度的误差因素.研究结果表明,基于该方法的动态小角度的重复测量精度可达到10-8rad数量级. 相似文献
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为了隔离载体扰动对天线指向的影响,研究了单基线GPS和微惯性传感器组合的低成本姿态估计及稳定方法。该方法以四元素和陀螺误差作为状态变量,根据陀螺角速率信息、加速度计的重力场信息和单基线GPS航向信息分别建立状态方程和量测方程,设计具有不同测量周期的平方根差分滤波分别融合惯性传感器和GPS信息,解决了加速度计与单基线GPS航向信息输出频率不一致问题;利用估计出的姿态角在角位置环路上对天线进行捷联稳定,隔离载体扰动。仿真结果表明,平方根差分滤波能有效估计出载体姿态,利用中等精度的微惯性器件可以满足动中通姿态稳定的需求。 相似文献
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为了适应现代靶场的测量空间目标姿态角的需要,介绍了一种在实验室进行了空中目标姿态角的测量的仿真实验,从实验需要出发,开发了一种精度较高的定标方案,并给出了交会测量、目标姿态角测量的数学模型,对该姿态测量的仿真系统的测量精度进行了计算与分析,给出了实验图像预处理过程,最终实验验证了该数学模型与该测量方案是可以用来进行空间目标姿态角的测量,姿态角的测量精度首先受目标特征点的坐标测量精度的影响,其次和测量精度关系比较密切的是2个测量面的交会角,该角越接近垂直测量精度越高。 相似文献
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利用传统的反正切法估算星敏感器测量姿态角偏差时,存在因计算量大干扰算法实时性等问题。针对上述问题,文中提出了根据星像位置误差直接估算星敏感器姿态角偏差的方法。通过分析星敏感器姿态测量原理,推导出星敏感器姿态角变化量对星像位置影响的数学关系式,进而在小视场条件下,得到星像位置误差与星敏感器姿态角测量偏差的公式。该公式计算过程简单,避免了大量的反正切计算。仿真结果表明,在相同的仿真实验条件下,该方法的计算时间比传统方法缩短了近四分之一,且该方法的计算精度也优于传统的反正切法。理论推导和仿真实验说明该方法具有计算量小、实时性好且精度较高的优点,具有一定的工程应用价值。 相似文献
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Abdullah Al-Hadi Azremi Janne Ilvonen Risto Valkonen Jari Holopainen Outi Kivekäs Clemens Icheln Pertti Vainikainen 《International Journal of Wireless Information Networks》2011,18(3):146-157
This paper presents a comprehensive simulation study on the performance of coupling element-based dual-antenna structures
on a mobile terminal at the 2,000 MHz Universal Mobile Telecommunications System (UMTS) frequency band with varying two significant
hand effects; vertical position of hand along terminal chassis, and distance between hand palm and terminal chassis. The results
reveal that in uniformly distributed isotropic environment, there exists a gain imbalance between antenna elements due to
hand effects and it is shown that a gain imbalance of 3.7 dB lead to a reduction of 1.9 dB in diversity gain at 99% reliability
level using maximal ratio combining (MRC) technique. For a dual-antenna configuration, the impact of gain imbalance on diversity
gain is more significant when only one antenna element is in close proximity to the hand, compared to when both antenna elements
are in the presence of the hand. It is also shown that a dual-antenna structure with elements vertically oriented along the
edges of a small 100 mm × 40 mm mobile terminal chassis achieves better performance in port-to-port isolation, gain imbalance
and diversity gain compared to other studied dual-antenna configurations when the user’s hand is present. 相似文献
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针对低精度微惯性测量单元/全球导航卫星系统 (IMU/GNSS)松组合导航系统中初始方位难以精确得到和行进间航向容易发散的问题,该文设计了一种双天线辅助的两段连续式对准方法。首先分析了初始方位误差对航向精度的影响;其次,由于GNSS测向系统精度高、无姿态漂移误差的特点,基于双天线基线矢量推导了一种最小二乘算法的测姿模型,进行初始对准;最后针对行进间对准,研究扩展了基于航向差值的1维量测以抑制航向发散。设计试验探讨了双天线基线矢量对初始对准与行进间航向精度的影响,改进方法可以使得初始方位误差优于0.7°,行进间航向能够更准确地被跟踪。针对目标的初始对准与行进间对准,双天线可提供辅助信息,其效果优于单天线IMU/GNSS的组合,且方法计算量适中。
相似文献13.
Experimental investigations of a new adaptive dual-antenna array for handset applications 总被引:2,自引:0,他引:2
Denidni T.A. McNeil D. Delisle G.Y. 《Vehicular Technology, IEEE Transactions on》2003,52(6):1417-1423
This paper presents the design and implementation of a new adaptive dual-antenna array for mitigation of both interference and multipath effects in digital mobile communications at the handset level. This proposed system employs a nonlinear adaptive algorithm in the front end of the receiver to enhance the transmission quality in confined areas. The enhancement is blind since no priori knowledge of spatial signatures or training sequences is required. Furthermore, to obtain a compact antenna array system, a miniaturized shorting postmicrostrip antenna that operates in the 1.9 GHz PCS band is used as a radiating element. Using this microstrip antenna, a new experimental adaptive dual-antenna array prototype was designed and implemented. To examine the expected performance of this approach, experimental measurements were carried out and the measured performances indicate that gain improvement of 7 dB can be achieved by using this approach. 相似文献
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Muhammad Saqib Rabbani Hooshang Ghafouri-Shiraz 《Journal of Infrared, Millimeter and Terahertz Waves》2017,38(5):548-566
In this paper, ultra-wide patch antenna arrays have been presented at 60 GHz band (57.24–65.88 GHz) with improved gain and beam-width capabilities for remote detection of respiration and heart beat rate of a person with Doppler radar principle. The antennas measured and simulation results showed close agreement. The breathing rate (BR) and heart rate (HR) of a 31-year-old man have been accurately detected from various distances ranging from 5 to 200 cm with both single-antenna and dual-antenna operations. In the case of single-antenna operation, the signal is transmitted and received with the same antenna, whereas in dual-antenna operation, two identical antennas are employed, one for signal transmission and the other for reception. It has been found that in case of the single-antenna operation, the accuracy of the remote vital sign monitoring (RVSM) is good for short distance; however, in the case of the dual-antenna operations, the RVSM can be accurately carried out at relatively much longer distance. On the other hand, it has also been seen that the visual results are more obvious with higher gain antennas when the radar beam is confined just on the subject’s body area. 相似文献
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李明 《太赫兹科学与电子信息学报》2021,19(4):569-572
为解决地对空快速单站无源定位问题,提出了一种长基线阵列地面单站无源定位方法.该方法将阵列天线嵌套在三天线长基线系统中,利用目标到长基线两端的视向夹角隐含在相位差参数上的原理,由视向夹角相位差估计角度变化率,同时利用阵列天线测出目标的实际方向,最后获得目标的位置参数.该方法可以在单个脉冲实现对目标的无源定位,仿真结果验证... 相似文献
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Yo-Sheng Lin Chun-Hao Hu Chi-Ho Chang Ping-Chang Tsao 《International Journal of Electronics》2018,105(6):993-1010
In this work, we demonstrate novel one-dimensional (1D) and two-dimensional (2D) antenna arrays for both microwave wireless power transfer (MWPT) systems and dual-antenna transceivers. The antenna array can be used as the MWPT receiving antenna of an integrated MWPT and Bluetooth (BLE) communication module (MWPT-BLE module) for smart CNC (computer numerical control) spindle incorporated with the cloud computing system SkyMars. The 2D antenna array has n rows of 1 × m 1D array, and each array is composed of multiple (m) differential feeding antenna elements. Each differential feeding antenna element is a differential feeding structure with a microstrip antenna stripe. The stripe length is shorter than one wavelength to minimise the antenna area and to prevent being excited to a high-order mode. That is, the differential feeding antenna element can suppress the even mode. The mutual coupling between the antenna elements can be suppressed, and the isolation between the receiver and the transmitter can be enhanced. An inclination angle of the main beam aligns with the broadside, and the main beam is further concentrated and shrunk at the elevation direction. Moreover, if more differential feeding antenna elements are used, antenna gain and isolation can be further enhanced. The excellent performance of the proposed antenna arrays indicates that they are suitable for both MWPT systems and dual-antenna transceivers. 相似文献
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为了提高旋转全球卫星导航系统(GNSS)短基线双天线/微惯性测量单元(MIMU)组合系统的定向精度,该文构建了其紧组合系统。紧组合算法将GNSS的伪距、伪距率和载波相位作为旋转GNSS双天线/MIMU组合系统的观测量,用扩展卡尔曼滤波进行估计,估计得到的状态量对系统进行闭环反馈,最后得到组合系统的定向结果。对旋转GNSS双天线/MIMU组合导航系统的船载试验数据进行了紧组合离线解算,结果表明,当GNSS基线为0.3 m时,组合系统的航向误差小于1°,俯仰角和横滚角误差小于0.1°。 相似文献
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InISAR系统能够在短观测时间内实现对目标的3维成像,在目标识别和分类中有广泛应用。但是ISAR成像平面不仅取决于目标相对雷达的空间位置,还和目标的运动情况有关。针对空间平稳运动目标,该文利用互相垂直的L型基线构成双通道InISAR系统,对各天线接收到的回波分别采用各自的参考距离进行聚焦处理,采用传统的距离-多普勒算法得到目标散射点2维像,通过提取各散射点的干涉相位和多普勒信息,采用最小二乘方法对目标的有效转动角速度大小和方向进行估计,进而估计出散射点的3维位置,实现目标3维成像。仿真实验验证了所提方法的有效性和鲁棒性。 相似文献