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卫星几何分布对GPS相对定位精度的影响 总被引:4,自引:0,他引:4
本文通过大量实例资料并从理论上进行分析论证卫星几何分布对GPS相对定位中基线精度的影响 ,在城市和矿区地面形变测量中 ,为了提高基线精度 ,提出了对GPS卫星几何分布有关的一些要求 相似文献
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针对姿态测量基于短基线精密相对定位,而观测值的周跳直接影响基线解算精度,将导致姿态解算结果数据质量下降的问题,提出了姿态测量应用中的周跳组合探测修复方法。文章在分析姿态解算原理及误差影响程度的基础上,结合经典电离层残差法和多项式拟合法,探讨其在北斗卫星导航系统中周跳探测修复的方法原理、缺陷及对北斗数据探测修复效果,结合实际情况提出了姿态测量应用中的组合探测修复方法。采集真实数据实时解算,定量计算了修复后的基线解算精度和姿态测量效果,验证了所提出的方法可用于实际测量解算,处理后的姿态测量精度满足使用需求,研究结果对北斗姿态解算有参考价值。 相似文献
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相比于单一卫星导航系统,多卫星导航系统组合具有显著增加可用卫星数目、改善卫星空间几何结构等优点,因而多卫星导航系统组合应用成为近年来关注的热点。在复杂观测条件下,利用BDS/GPS/GLONASS组合进行载体姿态测量具有单系统无法比拟的优势。首先阐述了BDS/GPS/GLONASS组合超短基线解算的双差模型以及姿态测量基本原理;然后分析了BDS/GPS/GLONASS组合多频单历元姿态测量性能。通过实测静态数据设置不同高度截止角进行分析表明:相比于单系统及双系统组合的姿态测量,BDS/GPS/GLONASS组合能够有效地提高姿态测量的精度、稳定性和可用性。当运动载体处于高楼、峡谷等受遮挡严重的复杂环境时,BDS/GPS/GLONASS组合单历元姿态测量更具有应用价值。 相似文献
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2011年8月在新疆天文台南山观测站首次进行了GPS与VLBI空间大地测量技术并置站的本地连接测量。针对南山并置站,本文在建立、优化南山GPS控制网的基础上,探讨本地连接测量中GPS数据处理的方法、精度。通过对GPS控制网7 d连续观测和基于IGS精密星历的GAMIT基线处理、三维空间平差,结果表明:基线在N、E和长度方向的重复性在0.3~0.4 mm,U方向分量重复性为1.4 mm,基线相对精度为0.8×10-8,达到《全球定位系统(GPS)测量规范》(GB/T 18314—2009)中A级网的精度要求,GPS控制点在ITRF2008系统下的坐标精度均优于0.5 mm。 相似文献
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以国家GNSS站的多系统观测数据为研究对象,旨在以单系统解算为研究视角,通过GAMIT软件对BDS/GPS数据进行单系统解算的方法,力图为利用BDS/GPS做基线解算提供参照。实验结果表明,BDS基线解算的相对精度与GPS相当;单BDS数据解算的基线东西方向精度10~12 mm,较单GPS数据解算的基线东西方向精度低42%,高程方向的单BDS基线中误差25 mm,是单GPS基线高程方向中误差的2倍;而组合双系统解算能有效提升基线U方向的精度,提升1 cm左右。文中认为目前利用BDS进行基线解算的精度尚不与GPS精度相当,在利用北斗系统进行高精度定位中,还有许多问题值得探讨。 相似文献
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Single-Epoch Ambiguity Resolution for Real-Time GPS Attitude Determination with the Aid of One-Dimensional Optical Fiber Gyro 总被引:9,自引:0,他引:9
High-accuracy real-time GPS-based attitude determination requires that integer ambiguities be resolved very quickly so that
the attitude angles can be output with minimum delay. This article describes an attitude determination algorithm that can
resolve integer ambiguities instantaneously, relative to one antenna of a multi-antenna array configuration. The carrier phase
and pseudorange observations are used with fixed baseline length constraints and fiberoptic gyro data. Real-time stochastic
model improvement using empirical elevation-dependent standard deviation function and an estimated scale factor are a feature
of this algorithm. Integer ambiguity search using the LAMBDA method, sophisticated validation criteria, and an adaptive procedure
has also been implemented within the software. An experiment was carried out using four Leica dual-frequency GPS receivers
(but only the L1 carrier phase and pseudorange data were used) and a low-cost fiberoptic on a car. The results indicate that
integer ambiguities can be resolved on a single-epoch basis with a 98.9% success rate. ? 1999 John Wiley & Sons, Inc. 相似文献
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Recent studies have demonstrated the usefulness of global positioning system (GPS) receivers for relative positioning of formation-flying satellites using dual-frequency carrier-phase observations. The accurate determination of distances or baselines between satellites flying in formation can provide significant benefits to a wide area of geodetic studies. For spaceborne radar interferometry in particular, such measurements will improve the accuracy of interferometric products such as digital elevation models (DEM) or surface deformation maps. The aim of this study is to analyze the impact of relative position errors on the interferometric baseline performance of multistatic synthetic aperture radar (SAR) satellites flying in such a formation. Based on accuracy results obtained from differential GPS (DGPS) observations between the twin gravity recovery and climate experiment (GRACE) satellites, baseline uncertainties are derived for three interferometric scenarios of a dedicated SAR mission. For cross-track interferometry in a bistatic operational mode, a mean 2D baseline error (1σ) of 1.4 mm is derived, whereas baseline estimates necessary for a monostatic acquisition mode with a 50 km along-track separation reveal a 2D uncertainty of approximately 1.7 mm. Absolute orbit solutions based on reduced dynamic orbit determination techniques using GRACE GPS code and carrier-phase data allows a repeat-pass baseline estimation with an accuracy down to 4 cm (2D 1σ). To assess the accuracy with respect to quality requirements of high-resolution DEMs, topographic height errors are derived from the estimated baseline uncertainties. Taking the monostatic pursuit flight configuration as the worst case for baseline performance, the analysis reveals that the induced low-frequency modulation (height bias) fulfills the relative vertical accuracy requirement (σ<1 m linear point-to-point error) according to the digital terrain elevation data level 3 (DTED-3) specifications for most of the baseline constellations. The use of a GPS-based reduced dynamic orbit determination technique improves the baseline performance for repeat-pass interferometry. The problem of fulfilling the DTED-3 horizontal accuracy requirements is still an issue to be investigated. DGPS can be used as an operational navigation tool for high-precision baseline estimation if a geodetic-grade dual-frequency spaceborne GPS receiver is assumed to be the primary instrument onboard the SAR satellites. The possibility of using only single-frequency receivers, however, requires further research effort.Deutsche Forschungsgemeinschaft (DFG) research fellow until Sept. 2004 at the Microwaves and Radar Institute, Deutsche Zentrum für Luft- und Raumfahrt (DLR) e.V., 82234 Weßling, Germany 相似文献
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为满足深空探测器的精确定姿需求,提出了一种惯性测量单元(IMU)辅助的X射线脉冲星定姿方法。该方法用IMU的速率陀螺来估计航天器短时姿态,观测两颗或多颗脉冲星的X射线辐射信号,将拟合得到的观测矢量作为滤波器信息输入,利用这两种测姿手段在时间和空间上的互补特性,提供一种全天候、抗干扰性强的定姿方法。仿真结果表明,相比于EKF,基于UKF的俯仰、横滚和偏航三姿态角的测量精度可提高21.9%、21.1%和31.7%;与仅使用脉冲星或IMU的定姿方法相比,组合定姿方法的俯仰角估计精度分别提高了32.5%和77.6%。 相似文献
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非合作目标的位姿监测,是空间目标态势感知的重要内容之一。本文提出了一种基于立体观测的非合作目标位姿变化监测方法,采用单目观测序列提取Harris角点,运用金字塔稀疏光流法对其进行运动跟踪,利用影像匹配和前方交会获取运动点三维坐标,最后将运动点坐标带入运动方程解算目标位姿变化。半实物仿真试验结果表明:相机距目标距离约为2.5 m时,位置变化检测精度优于2.5 mm,姿态变化检测精度优于0.5°。相比于基于先验信息和特征提取的传统方法,该方法基本满足对非合作目标监测、跟踪、绕飞时位姿测量需求,且在适应性和精度上均有提高。 相似文献
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基于几何约束的GPS测姿系统的原理和实验 总被引:1,自引:0,他引:1
详细描述了GPS测姿系统的原理,并给出了一种基于基线长度约束和空间几何约束的最小二乘模糊度搜索算法,并经过静态和动态车载试验证明GPS测姿系统切实可行,在基线长度为3m的条件下,航向角精度优于0.1°。 相似文献
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陆地导航中GNSS/陀螺仪组合实时测姿方法 总被引:2,自引:0,他引:2
在陆地导航系统中使用GNSS/INS组合导航会增加系统成本,多天线GNSS测姿精度受基线长度影响,且存在的模糊度固定问题。本文提出仅利用一个陀螺仪和单天线GNSS组合来进行实时测姿。先由单天线GNSS计算姿态角3参数,航向角为陆地导航的关键参数,为此将陀螺信息与GNSS导出的航向角进行融合。分析了单天线测姿在载体静止或低速运动时精度很差的原因,提出了在组合滤波中进行解决的方案。推导了GNSS和陀螺信息融合的滤波模型,将陀螺仪信息作为状态模型的控制输入,以GNSS航向为滤波观测值。实验结果表明,GNSS/陀螺仪组合计算的航向角精度和可靠性相对GNSS测姿结果均有很大提升。 相似文献
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利用GPS载波相位观测值进行基线测定具有重要意义。本文讨论了基线测定中卫星星历误差对定位结果的影响,提出了基线上轨道改进的定位方法,编制了基线测定的定位软件,并使用高精度基线上的实际观测资料进行了计算。计算结果表明在基线上用轨道改进定位方法是可行的,可以提高定位精度。 相似文献