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分析了先难误差对于GPS网平差的意义,指出先验误差的计算及确定的一些方法;最后说明如何在GPS网平差中进行加权配置。 相似文献
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关于GPS网平面基准点的可靠性分析 总被引:4,自引:1,他引:4
通过具体实例,对GPS网约束平差结果进行分析、比较,并提出GPS网平面基准点的可靠性检验方法,得出作为起算数据的基准点,其点位误差对GPS网约束平差精度的影响规律。 相似文献
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GPS网间接平差是测绘类本科专业误差理论与测量平差基础教学的重要组成部分。本文针对GPS网间接平差存在的观测数据多、计算量大、在实际课堂教学中很难讲解清楚等问题,提出基于Matlab的GPS网间接平差教学设计与实现方法。给出GPS网间接平差课堂教学的内容及难点,阐述基于Matlab的GPS网间接平差程序设计流程及关键步骤的实现方法。结合3个具体的GPS网平差实例,展示程序运行的结果。结果表明,基于Matlab进行GPS网间接平差教学既有助于加深学生对GPS网间接平差理论知识的理解,培养学生理论联系实际的能力,又可以实现学生所学计算机高级编程语言与专业知识的有机结合,提高学生的编程能力和学习兴趣。 相似文献
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导出了由于GPS网空间无约束平差的基准点定位误差而引起的大地坐标误差,高斯平面坐标误差、转换参数误差及转换后GPS点坐标误差的微分计算公式。并通过示例对公式的正确性进行了检验。 相似文献
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GPS测量误差与数据处理的质量控制 总被引:3,自引:1,他引:3
针对GPS测量结果的误差来源,从GPS卫星信号传播过程、观测条件和数据处理等方面讨论了GPS控制网数据处理的质量控制问题,介绍怎样进行基线解算和网平差的质量控制,并阐述了提高GPS网精度的若干方法。 相似文献
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在具有多类观测值的控制网平差中,各类观测值的先验权是否正确给定将直接影响控制网平差的质量,本文论述网的质量与定先验权误差间数学关系,提出采用先验与验后单位权观测值中误差一致的原则来确定各类观测值的权比,从而达到定权合理,提高平差质量的目的。 相似文献
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Steffen Schön 《GPS Solutions》2007,11(2):107-117
GPS is a promising tool for real-time monitoring of deformations of slopes or large structures. However, remaining systematic
effects in GPS phase observations after double differencing and application of a priori models affect the resulting coordinates.
They complicate the proper separation of the actual deformations from pseudo-deformations induced by the systematic effects.
This paper shows that for small monitoring networks (baseline lengths <5 km) only affine distortions of the network geometry
are generated by the remaining distance dependent systematic effects, e.g. unmodelled tropospheric and ionospheric propagation
effects, or satellite orbit errors. Hence, a generic correction model is given by a three-dimensional affine transformation
involving a maximum of 12 transformation parameters. For the determination of these parameters, four high quality GPS stations
are necessary which are not affected by the actual deformations to be monitored. Based on the analysis of network geometries
of synthetic GPS networks with large height differences and considering the physics of the GPS observations it is shown, however,
that less than 12 parameters are sufficient for the computation of the corrections. The proposed 8 parameter model was applied
to the GPS monitoring network of the Gradenbach landslide. For this small network with large height differences, it was shown
that the distortions can be reduced by about 75%. 相似文献
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探讨了隧道GPS网在设计阶段估算横向贯通误差的基本理论,对按该理论编制的软件进行了计算正确性的验证。结合铁路测量规则对不同长度的隧道GPS网横向贯通误差进行了计算分析,提出了分设隧道GPS网的一些基本原则和隧道GPS网横向贯通误差的近似估算方法 相似文献
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GPS导航解算中常用最小二乘算法。随着高动态用户需求精度的不断提高,且由于线性化忽略高次项,初始值精度低以及差分后剩余或放大误差的存在。导航解精度很难满足高动态用户的需求。为此,本文基于BP神经网络的非线性逼近性能。给出了基于BP神经网络的GPS导航算法。实测数据计算结果表明该算法能够真实地反映载体运动轨迹,其导航解的精度和可靠性有明显的提高。 相似文献
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Testing of global pressure/temperature (GPT) model and global mapping function (GMF) in GPS analyses 总被引:1,自引:1,他引:0
J. Kouba 《Journal of Geodesy》2009,83(3-4):199-208
Several sources of a priori meteorological data have been compared for their effects on geodetic results from GPS precise point positioning (PPP). The new global pressure and temperature model (GPT), available at the IERS Conventions web site, provides pressure values that have been used to compute a priori hydrostatic (dry) zenith path delay z h estimates. Both the GPT-derived and a simple height-dependent a priori constant z h performed well for low- and mid-latitude stations. However, due to the actual variations not accounted for by the seasonal GPT model pressure values or the a priori constant z h, GPS height solution errors can sometimes exceed 10 mm, particularly in Polar Regions or with elevation cutoff angles less than 10 degrees. Such height errors are nearly perfectly correlated with local pressure variations so that for most stations they partly (and for solutions with 5-degree elevation angle cutoff almost fully) compensate for the atmospheric loading displacements. Consequently, unlike PPP solutions utilizing a numerical weather model (NWM) or locally measured pressure data for a priori z h, the GPT-based PPP height repeatabilities are better for most stations before rather than after correcting for atmospheric loading. At 5 of the 11 studied stations, for which measured local meteorological data were available, the PPP height errors caused by a priori z h interpolated from gridded Vienna Mapping Function-1 (VMF1) data (from a NWM) were less than 0.5 mm. Height errors due to the global mapping function (GMF) are even larger than those caused by the GPT a priori pressure errors. The GMF height errors are mainly due to the hydrostatic mapping and for the solutions with 10-degree elevation cutoff they are about 50% larger than the GPT a priori errors. 相似文献
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为合理利用边坡的几何信息和物理信息,控制几何观测异常对形变参数估计的影响,建立了一种带有未知系统误差的滤波模型,并给出了一种基于移动窗口的系统误差自适应拟合法,同时给出了相应的状态预测向量的协方差矩阵估计方法。GPS监测网的计算结果表明,该算法可以通过拟合地球物理信息来减弱观测异常所带来的影响,提高形变参数解算精度。 相似文献