scholarly journals The Functional Models of System of the Automated Design of the Railroads on the Basis of Use of Three-dimensional Terrain Models

2016 ◽  
Vol 165 ◽  
pp. 1873-1879
Author(s):  
Vladimir Anisimov ◽  
Kseniia Malykh ◽  
Aleksandr Anisimov ◽  
Arkadii Edigarian
GPS Solutions ◽  
2021 ◽  
Vol 25 (2) ◽  
Author(s):  
Luca Carlin ◽  
André Hauschild ◽  
Oliver Montenbruck

AbstractFor more than 20 years, precise point positioning (PPP) has been a well-established technique for carrier phase-based navigation. Traditionally, it relies on precise orbit and clock products to achieve accuracies in the order of centimeters. With the modernization of legacy GNSS constellations and the introduction of new systems such as Galileo, a continued reduction in the signal-in-space range error (SISRE) can be observed. Supported by this fact, we analyze the feasibility and performance of PPP with broadcast ephemerides and observations of Galileo and GPS. Two different functional models for compensation of SISREs are assessed: process noise in the ambiguity states and the explicit estimation of a SISRE state for each channel. Tests performed with permanent reference stations show that the position can be estimated in kinematic conditions with an average three-dimensional (3D) root mean square (RMS) error of 29 cm for Galileo and 63 cm for GPS. Dual-constellation solutions can further improve the accuracy to 25 cm. Compared to standard algorithms without SISRE compensation, the proposed PPP approaches offer a 40% performance improvement for Galileo and 70% for GPS when working with broadcast ephemerides. An additional test with observations taken on a boat ride yielded 3D RMS accuracy of 39 cm for Galileo, 41 cm for GPS, and 27 cm for dual-constellation processing compared to a real-time kinematic reference solution. Compared to the use of process noise in the phase ambiguity estimation, the explicit estimation of SISRE states yields a slightly improved robustness and accuracy at the expense of increased algorithmic complexity. Overall, the test results demonstrate that the application of broadcast ephemerides in a PPP model is feasible with modern GNSS constellations and able to reach accuracies in the order of few decimeters when using proper SISRE compensation techniques.


2016 ◽  
Vol 1 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Canan Yemenicioglu ◽  
Sinasi Kaya ◽  
Dursun Zafer Seker

2014 ◽  
Vol 687-691 ◽  
pp. 4101-4104
Author(s):  
Xi Zhe Peng

Large area real terrain modeling is the key technology in visual simulation system. This thesis discusses the terrain modeling technology based on the GeoTIFF data, which transform the GeoTIFF data to DEM using the Global Mapper. And then, the three dimensional terrain models are established through Creator environment, the real terrain modeling is implemented quickly.


2014 ◽  
Vol 20 (5) ◽  
pp. 422-430 ◽  
Author(s):  
Sanat Agrawal ◽  
Deon J. de Beer ◽  
Yashwant Kumar Modi

Purpose – This paper aims to convert surface data directly to a three-dimensional (3D) stereolithography (STL) part. The Geographic Information Systems (GIS) data available for a terrain are the data of its surface. It doesn’t have information for a solid model. The data need to be converted into a three-dimensional (3D) solid model for making physical models by additive manufacturing (AM). Design/methodology/approach – A methodology has been developed to make the wall and base of the part and tessellates the part with triangles. A program has been written which gives output of the part in STL file format. The elevation data are interpolated and any singularity present is removed. Extensive search techniques are used. Findings – AM technologies are increasingly being used for terrain modeling. However, there is not enough work done to convert the surface data into 3D solid model. The present work aids in this area. Practical implications – The methodology removes data loss associated with intermediate file formats. Terrain models can be created in less time and less cost. Intricate geometries of terrain can be created with ease and great accuracy. Social implications – The terrain models can be used for GIS education, educating the community for catchment management, conservation management, etc. Originality/value – The work allows direct and automated conversion of GIS surface data into a 3D STL part. It removes intermediate steps and any data loss associated with intermediate file formats.


2021 ◽  
Vol 14 ◽  
pp. 63-70
Author(s):  
Andreas Bürgi

Among the processes of “conquering, developing and appropriating mountains” is occupied by the emergence of mountain topography. In the eighteenth century raised relief, as a terrain model, played one of the most important roles in this process. This was a period when more reliable topographic data began to be collected on the basis of measurements carried out across the Alps. Possibilities of their cartographic representation were limited at the time. A graphic method for presenting orthogonal projection by means of contour curves was not invented until the nineteenth century. Before that three-dimensional terrain models were the only way to correctly represent various levels of landscape. Terrain models were accepted at the time as the best method for presenting mountain landscapes. The first attempt to carry out a comprehensive measurement of the Alps over a vast area of a continuous mountain range and represent it on a low relief was made in 1786 and concerned an area in central Switzerland around Lake Lucerne. At that time Franz Ludwig Pfyffer von Wyher, an officer in French service, became famous for advanced surveying techniques and terrain models, both civilian and military. His famous relief depicts around one-tenth of today’s Switzerland, with two-thirds of the area encompassing the Alps and foot of the Alps. From that moment on other authors began to create their models of Alpine landscape. These reliefs were appreciated by contemporary naturalists, especially those studying the Alps, because they enabled them to view the complex topography of the range, which had been impossible before. They drew attention to a number of natural and geological phenomena, and made it possible to come up with new findings relating to the following questions: At what altitude should the snow line be placed? Where is the boundary of vegetation? Where do coniferous forests begin? Where is the line of glaciers? What is the structure of the mountains? Obviously, they were not sufficient to provide all answers to the above questions, but thanks to a “bird’s eye” perspective they made it possible to place special studies of the various disciplines within a broader context, both with regard to the relevant subject matter and between disciplines.


Author(s):  
Oyunkhand Byamba ◽  
◽  
Elena L. Kasyanova ◽  

The development of science always depends on technological progress. Cartography is rapidly changing and developing with the introduction of new computer technologies, such as GIS and remote sensing of the Earth. Recently, there have been qualitatively new types of cartographic products, in particular 3D terrain models, which in cartography are becoming a universal, optimal and operational method for displaying terrain. The article discusses a method for creating a three-dimensional digital terrain model in the form of an irregular triangulation network based on SRTM data and GIS technology on the example of the Khenti aimag of Eastern Mongolia.


2019 ◽  
Vol 25 (12) ◽  
pp. 1885-1893 ◽  
Author(s):  
Fabián Segovia-Miranda ◽  
Hernán Morales-Navarrete ◽  
Michael Kücken ◽  
Vincent Moser ◽  
Sarah Seifert ◽  
...  

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