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Date submitted2023-09-05
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Date accepted2024-11-07
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Date published2025-02-25
Investigation of the accuracy of constructing digital elevation models of technogenic massifs based on satellite coordinate determinations
At all stages of the life cycle of buildings and structures, geodetic support is provided by electronic measuring instruments – a laser scanning system, unmanned aerial vehicles, and satellite equipment. In this context, a set of geospatial data is obtained that can be presented as a digital model. The relevance of this work is practical recommendations for constructing a local quasigeoid model and a digital elevation model (DEM) of a certain accuracy. A local quasigeoid model and a DEM were selected as the study objects. It is noted that a DEM is often produced for vast areas, and, therefore, it is necessary to build a local quasigeoid model for such models. The task of assessing the accuracy of constructing such models is considered; its solution will allow obtaining a better approximation to real data on preassigned sets of field materials. A general algorithm for creating both DEM and local quasigeoid models in the Golden Software Surfer is presented. The constructions were accomplished using spatial interpolation methods. When building a local quasigeoid model for an area project, the following methods were used: triangulation with linear interpolation (the least value of the root mean square error (RMSE) of interpolation was 0.003 m) and kriging (0.003 m). The least RMSE value for determining the heights by control points for an area project was obtained using the natural neighbour (0.004 m) and kriging (0.004 m) methods. To construct a local quasigeoid model for a linear project, the following methods were applied: kriging (0.006 m) and triangulation with linear interpolation (0.006 m). Construction of the digital elevation model resulted in the least aggregate value of the estimated parameters: on a flat plot of the earth’s surface – the natural neighbour method, for a mountainous plot with anthropogenic topography – the quadric kriging method, for a mountainous plot – quadric kriging.
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Date submitted1951-07-15
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Date accepted1951-09-03
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Date published1952-03-26
Comparative analysis of joint and separate adjustment of two points of mine survey triangulation
- Authors:
- V. G. Zdanovich
The article studies the relationship between the errors in the position of two mine triangulation points rigidly inserted into the existing base network, with their separate and joint adjustment. The solution to this problem is of considerable interest to mine surveying practice when replenishing the existing mine triangulation network with new points as mining operations develop. In this case, when inserting new points, the mine surveyor is forced to accept previously determined points as initial ones, due to which sometimes a significant number of stages in constructing the network arises and its accuracy is reduced to a certain extent. The mine surveyor must be able to quantitatively assess the loss of accuracy of network elements caused by separate adjustment of existing and newly determined points, and on this basis decide on the choice of one or another scheme for inserting points and the most appropriate use of the reference network when solving mine surveying and other engineering problems. If the mine network points are determined simultaneously, then preference, of course, should be given to their joint adjustment, since under normal conditions it always increases the weight to a certain extent elements of the network. But even in this case, the results obtained in the article are of interest, since they shed new light on the issue of the relationship between the weights of network elements in separate and joint equalization of the points being determined and allow a more correct assessment of the merits of the latter.
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Date submitted1951-07-15
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Date accepted1951-09-08
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Date published1952-03-26
Taking into account the influence of errors of initial points when assessing the accuracy of mine survey triangulation networks
- Authors:
- V. G. Zdanovich
When using formulas of the theory of errors and the method of least squares for assessing the accuracy of triangulation networks, it is necessary to strive for the most complete consideration of all sources of errors that affect the accuracy of determining the elements of the network. This applies primarily to the influence of errors in the initial data, the issue of taking into account which has repeatedly attracted the attention of geodesists and mine surveyors. In the existing works devoted to this issue, the most detailed solution is based on the direct application of the main formula of the theory of errors to the function of interest to us, which is preliminarily expressed through directly measured quantities (see article). The strict formulas given in the mentioned works, however, are difficult to apply to the analysis of the accuracy of mine survey triangulations, which are usually rigid networks of the lowest construction queues and have a significant amount of initial data. The use of these formulas is associated with the production of very cumbersome calculations that do not have sufficient clarity and hide from the calculator the mechanism of accumulation of errors in the network, thereby complicating the transition to approximate methods of assessing accuracy. To solve some specific problems of assessing the accuracy of network elements encountered in mine surveying practice, it is possible to derive special formulas that solve these problems much more simply and clearly.