共查询到20条相似文献,搜索用时 15 毫秒
1.
This paper discusses theoretically the stability of solutions for dynamic geodetic network adjustment, Kalman filtering and sequence adjustment, and two examples are given. The solution for dynamic geodetic network adjustment is stable if the dynamic geodetic network is a classical network. There is not rank deficit in datum, or else the solution is not stable, which will depend on the initial value. 相似文献
2.
C. Kotsakis 《Journal of Geodesy》2013,87(7):661-673
The estimated coordinates from a minimum-constrained (MC) network adjustment are generally influenced by two different error sources, that is the data noise from the available measurements and the so-called datum noise due to random errors in the fiducial coordinates that are used for the datum definition with regard to an external reference frame. Although the latter source does not affect the estimable characteristics of a MC solution, it still contributes a datum-related noise to the estimated positions which reflects the uncertainty of the coordinate system itself for the adjusted network. The aim of this paper is to develop a new type of MCs which minimizes both of the aforementioned effects in the final coordinates of an adjusted network. This particular problem has not been treated in the geodetic literature and the solution which is presented herein offers an elegant unification of the classic inner constraints into a more general framework for the datum choice problem of network optimization theory. Furthermore, the findings of our study provide a useful and rigorous tool for frame densification problems by means of an optimal MC adjustment in geodetic networks. 相似文献
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王解先 《武汉大学学报(信息科学版)》1996,(3)
采用数值微商求偏导数的方法,从而使GPS网平差的计算模型非常简洁。选用平面坐标和大地高作为平差参数,可以方便地简化为平面网或高程网,加入地面归心数据和常规观测数据也变得十分容易。对旋转角大的地方独立坐标系,提出了处理办法。经对实测数据的处理,证明了模型的正确性 相似文献
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天文大地网与GPS2000网联合平差的地壳形变改正研究 总被引:3,自引:0,他引:3
按照中国大陆地质构造情况,将中国大陆划分成不规则的曲线网格.利用高精度GPS网平差得到的GPS速度、地震矩张量和活断层滑动速率。采用双三次样条函数拟合的方法。求出了中国大陆现今地壳运动速度场和变形场;利用中国大陆现今地壳运动速度场和变形场模型。研究分析了天文大地网与GPS2000网联合平差中是否需要对天文大地网地面观测值进行形变改正问题。研究结果表明。天文大地网观测点坐标需要改正,但不需要在联合平差中对天文大地网地面观测数据(边长、方位角)进行改正,可以省去天文大地网约30万个观测量的地壳形变改正工作。 相似文献
7.
国家高精度GPS网整体平差中的粗差分析 总被引:1,自引:0,他引:1
分析了国家高精度GPS网中的粗差观测量的特点,提出了采用相关分析的粗差探测理论,对国家高精度GPS网的各子网和相邻子网进行粗差探测,并采用稳健估计的平差方法,消除粗差对平差结果的影响,大大提高了国家高精度GPS网的整体平差精度。 相似文献
8.
This paper deals with transformation procedures for observed GPS data from the world geodetic system WGS-84 into the national geodetic grid datum S-UTCN(system of united trigonometric cadaster network) and Baa(the Baltic Sea after adjustment).Transformation from WGS-84 into SUTCN is performed most frequently by means of the 7-element Helmert transformation with three identical points.Geodetic network was adjusted by two ways. 相似文献
9.
This paper deals with transformation procedures for observed GPS data from the world geodetic system WGS-84 into the national geodetic grid datum S-UTCN (system of united trigonometric cadaster network) and Baa (the Baltic Sea after adjustment). Transformation from WGS-84 into SUTCN is performed most frequently by means of the 7-element Helmert transformation with three identical points. Geodetic network was adjusted by two ways. 相似文献
10.
《Journal of Geodesy》1975,49(3):241-257
The parallelism of geodetic and satellite systems to the average terrestrial system is examined, under the assumption that
a geodetic system is a fixed framework invariant with respect to geodetic network adjustment. In this case a geodetic system
is rotated with respect to the average terrestrial system only about the ellipsoid normal of the initial point. The method
is demonstrated using coordinates and covariance matrices for BC-4 and SECOR satellite tracking stations computed by Mueller
and his co-workers. It is shown that the NAD geodetic system is scaled significantly larger than the satellite systems; the
SECOR satellite systems have significant Z-rotations with respect to the average terrestrial system; and the ETH geodetic
system may have a significant rotation with respect to the average terrestrial system. 相似文献
11.
G. K. Sherurah 《Journal of Geodesy》1970,44(1):71-85
This paper is a summary of an unpublished paper and it attempts to give a complete solution of the problem posed by the presence
of systematic errors in precise spirit levelling, using mathematical statistics. Distribution-free statistics, which do not
require the precise knowledge of the distribution of the underlying populations, are used and to this end, a value of the
expected systematic error in any given section is isolated from the total discrepancy of the independent mutual levelling
operations thus facilitating a plausible least square adjustment of the geodetic network. The problem of weighting is considered
in relation to the rank test-statistics. Complete mathematical derivations are not attempted in this summary. 相似文献
12.
动态大地测量的平差基准 总被引:1,自引:0,他引:1
从平差基准的基本概念出发 ,说明动态大地测量的平差基准的意义和基准的数量 ,讨论动态高程系统的转换关系 ,建立等价于原观测值的坐标差与速率差的观测方程及基准方程 ,并通过分析说明 ,四维大地测量平差必须恰当地选取平差基准 ,才能得到具有参考价值的结果。 相似文献
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Many geodetic applications require the minimization of a convex objective function subject to some linear equality and/or inequality constraints. If a system is singular (e.g., a geodetic network without a defined datum) this results in a manifold of solutions. Most state-of-the-art algorithms for inequality constrained optimization (e.g., the Active-Set-Method or primal-dual Interior-Point-Methods) are either not able to deal with a rank-deficient objective function or yield only one of an infinite number of particular solutions. In this contribution, we develop a framework for the rigorous computation of a general solution of a rank-deficient problem with inequality constraints. We aim for the computation of a unique particular solution which fulfills predefined optimality criteria as well as for an adequate representation of the homogeneous solution including the constraints. Our theoretical findings are applied in a case study to determine optimal repetition numbers for a geodetic network to demonstrate the potential of the proposed framework. 相似文献
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利用全球定位系统(GPS)所建立的空间基线向量网,对于改善已有地面网,分析网的系统误差和进行地球动力学的监测等具有广泛的意义。本文着重讨论了上述空间基线向量网和地面控制网的三维联合平差和二维联合平差的方法和模型。指出,为了避免地面网高程误差以及引入地面网尺度因子的模型误差对三维联合平差结果的影响,在二维大地坐标系统中进行上述两网联合平差的方法具有重要的现实意义。 相似文献
16.
Haim B. Papo 《Journal of Geodesy》1985,59(4):378-390
The contribution of geodetic measurements to the establishment of a control network can be partitioned into global and local
(individual) components. The global component epitomized in a number of geometrically meaningful parameters can be estimated
together with the individual point coordinates. The additional rank defect created by the extension of the parameter list
is corrected by free net adjustment constraints which are extended beyond those needed for a solution of the network datum
problem. Two applications of extended free net adjustment are outlined and illustrated by elementary numerical examples. A
non-Cartesian (skew) reference system discussed in the Appendix provides an exotic interpretation of the estimated global
and individual parameters.
Prepared during a grant period (September 1984 through February 1985) while serving as a Visiting Senior Scientist in Geodesy,
National Research Council, National Academy of Sciences, Washington, D.C. 相似文献
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坐标基准维持与动态监测网数据处理 总被引:5,自引:0,他引:5
坐标基准的维持不仅要求有高精度的连续大地测量观测或定期复测,还要求采用合理的数据处理原则与方法。分析了不同平差方法对基准的影响,其中包括经典整体平差、序贯平差和自适应序贯平差。利用GPS监测网数据进行了计算与分析,结果表明,当个别点位发生异常移动或变形时,序贯平差会使坐标基准产生实际的扭曲,而自适应序贯平差则能有效控制异常点位对平差基准的影响,保证了坐标基准的可靠性和现势性。 相似文献
19.
Dennis G. Milbert 《Journal of Geodesy》1980,54(2):235-245
This paper examines computer roundoff error accumulation in the least-squares adjustment of horizontal geodetic networks containing
positions of very poor geometry. Roundoff error accumulates at the weak unknowns but does not disturb the solution of well-determined
positions. Numerical results are given. 相似文献
20.
基于JSCORS的江苏省现代大地坐标框架的建设与维护 总被引:2,自引:2,他引:0
本文结合江苏省现代大地坐标框架的建设和JSCORS的运行维护,通过对江苏省原大地坐标框架的情况分析,介绍了江苏大地坐标框架的建设方案.结合区域稳定基点组的确定、框架维护和复测机制的建立、框架维护系统的建设等内容,提出江苏省大地坐标框架维护的解决方案. 相似文献