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1.
L. A. Kivioja 《Journal of Geodesy》1971,45(1):55-63
By choosing sufficiently small elements of the length of the geodetic line, or of the latitude or longitude difference, the
other two can be computed at each element and the results can be accumulated to solve the problem with more than twenty significant
number accuracy if desired. Ten to twelve number accuracy was computed in the examples of this paper. The geodetic line elements
are kept in correct azimuth by Clairaut’s equation for the geodetic line. The computers can do millions of necessary computations
very economically in a few seconds. All other published methods solving the direct or indirect problem can be reliably checked
against results obtained by this method. The run of geodetic lines around the back side of the Ellipsoid is outlined. 相似文献
2.
大地测量反演在解决人类面临的资源短缺、自然灾害和生态环境退化问题显示出越来越重要的作用和地位。本文根据R.Parker的理论,首次尝试将近三十年来大地测量反演问题从解的存在性、模型构制、解的非唯一性、解的评价四个方面进行统一,促进了大地测量反演理论和应用的研究。 相似文献
3.
Experiments photographing satellite reflected laser pulses have been made to demonstrate the feasibility of using an earth-based
light source to illuminate satellites. The reflection was also recorded photoelectrically for range information. The reflections
are photographed against stellar backgrounds from which the angular positions of the satellites relative to the laser site
can be determined. With the angular information and the range data from the laser-illuminator, the position of the satellite
in space is uniquely determined. When other widely separated laser-camera sites make simultaneous observations, the location
of these sites relative to the “control” site can be found. 相似文献
4.
Various formulations of the geodetic fixed and free boundary value problem are presented, depending upon the type of boundary data. For the free problem, boundary data of type astronomical latitude, astronomical longitude and a pair of the triplet potential, zero and first-order vertical gradient of gravity are presupposed. For the fixed problem, either the potential or gravity or the vertical gradient of gravity is assumed to be given on the boundary. The potential and its derivatives on the boundary surface are linearized with respect to a reference potential and a reference surface by Taylor expansion. The Eulerian and Lagrangean concepts of a perturbation theory of the nonlinear geodetic boundary value problem are reviewed. Finally the boundary value problems are solved by Hilbert space techniques leading to new generalized Stokes and Hotine functions. Reduced Stokes and Hotine functions are recommended for numerical reasons. For the case of a boundary surface representing the topography a base representation of the solution is achieved by solving an infinite dimensional system of equations. This system of equations is obtained by means of the product-sum-formula for scalar surface spherical harmonics with Wigner 3j-coefficients. 相似文献
5.
The AuScope geodetic VLBI array 总被引：1，自引：1，他引：0
J. E. J. Lovell J. N. McCallum P. B. Reid P. M. McCulloch B. E. Baynes J. M. Dickey S. S. Shabala C. S. Watson O. Titov R. Ruddick R. Twilley C. Reynolds S. J. Tingay P. Shield R. Adada S. P. Ellingsen J. S. Morgan H. E. Bignall 《Journal of Geodesy》2013,87(6):527-538
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7.
Various formulations of the geodetic fixed and free boundary value problem are presented, depending upon the type of boundary
data. For the free problem, boundary data of type astronomical latitude, astronomical longitude and a pair of the triplet
potential, zero and first-order vertical gradient of gravity are presupposed. For the fixed problem, either the potential
or gravity or the vertical gradient of gravity is assumed to be given on the boundary.
The potential and its derivatives on the boundary surface are linearized with respect to a reference potential and a reference
surface by Taylor expansion. The Eulerian and Lagrangean concepts of a perturbation theory of the nonlinear geodetic boundary
value problem are reviewed. Finally the boundary value problems are solved by Hilbert space techniques leading to new generalized
Stokes and Hotine functions. Reduced Stokes and Hotine functions are recommended for numerical reasons. For the case of a
boundary surface representing the topography a base representation of the solution is achieved by solving an infinite dimensional
system of equations. This system of equations is obtained by means of the product-sum-formula for scalar surface spherical
harmonics with Wigner 3j-coefficients. 相似文献
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10.
Robustness analysis of geodetic horizontal networks 总被引：2，自引：1，他引：2
11.
J. Gazdzicki 《Journal of Geodesy》1976,50(4):363-376
In strength analysis of horizontal geodetic networks it is appropriate to use pairs of functions which involve the relative
position of two points and relative position of three points. Using properly chosen pairs of functions, formulae are given
which allow the computation of precision criteria for the orientation and scale of the network as well as its shape. To illustrate
the presentation of results, new types of errors ellipses are introduced. Analogies and correlations existing among the adopted
functions are introduced by using the concept of orthogonal networks which are defined in the paper. 相似文献
12.
F. Morrison 《Journal of Geodesy》1977,51(2):105-118
Most authors using statistical interpolation techniques on geodetic data have assumed isotropy for the undulation autocorrelation.
Tests of actual data,414 deflections of the vertical, indicate this assumption is not valid. The results of interpolation, however, are not very sensitive
to the parameters in the covariance function. A special limiting case for which statistical interpolation degenerates into
a completely deterministic process is given in the spherical domain. In this case the covariance function has absolutely no
effect on the results, so that the covariance of the output of a prediction need not be that assumed for the interpolation.
This provides a self-correcting process whereby the information in the data corrects for a poor choice of covariance function.
Estimates of the precision of the interpolation, on the other hand, are very sensitive to the covariance function, particularly
to the modeling of azimuth dependence. A simple procedure for generalizing isotropic functions to azimuth dependence is given,
which provides sufficiently accurate estimates of precision. The advisability of trend removal is illustrated by some numerical
examples. 相似文献
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15.
Robust estimation of geodetic datum transformation 总被引：18，自引：1，他引：17
Y. Yang 《Journal of Geodesy》1999,73(5):268-274
The robust estimation of geodetic datum transformation is discussed. The basic principle of robust estimation is introduced.
The error influence functions of the robust estimators, together with those of least-squares estimators, are given. Particular
attention is given to the robust initial estimates of the transformation parameters, which should have a high breakdown point
in order to provide reliable residuals for the following estimation. The median method is applied to solve for robust initial
estimates of transformation parameters since it has the highest breakdown point. A smooth weight function is then used to
improve the efficiency of the parameter estimates in successive iterative computations. A numerical example is given on a
datum transformation between a global positioning system network and the corresponding geodetic network in China. The results
show that when the coordinates are contaminated by outliers, the proposed method can still give reasonable results.
Received: 25 September 1997 / Accepted: 1 March 1999 相似文献
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17.
Herman van Gysen 《Journal of Geodesy》1994,68(3):173-179
Thin-plate splines — well known for their flexibility and fidelity in representing experimental data — are especially suited for the numerical evaluation of geodetic integrals in the area where these are most sensitive to the data, i.e. in the immediate vicinity of the computation point. Quadrature rules that are exact for thin-plate splines interpolating randomly spaced data are derived for the inner zone contribution (to a planar approximation) to Stokes's formula, to the formulae of Vening Meinesz and to theL
1 gradient operator in the analytical continuation solution of Molodensky's problem.The quadrature method is demonstrated by calculating the inner zone contribution to height anomalies in a mountainous area of Lesotho and carrying out a comparison with GPS-derived heights. Height anomalies are recovered with an accuracy of 6 cm. 相似文献
18.
T. Vincenty 《Journal of Geodesy》1985,59(2):189-199
After deriving models for changes of coordinates and azimuths due to rotations, the investigation considers methods for modeling
terrestrial orientation in adjustments of geodetic networks. If a misorientation of a geodetic network exists, this can be
due to systematic errors in astronomic longitude or in astronomic azimuth, or in both. A separation of these two effects is
not possible in practice. The initial azimuth at the datum origin contributes to the orientation only as much as any other
azimuth of the same weight. 相似文献
19.
O. Remmer 《Journal of Geodesy》1969,43(2):99-122
A method for filtering of geodetic observationwhich leaves the final result normally distributed, is presented. Furthermore, it is shown that if you sacrifice100.a% of all the observations you may be (1−β).100% sure that a gross error of the size Δ is rejected.
Another and, may be intuitively, more appealing method is presented; the two methods are compared and it is shown why Method
1 should be preferred to Method 2 for geodetic purposes.
Finally the two methods are demonstrated in some numerical examples. 相似文献