scholarly journals Accurate and Efficient Calculation of Three-Dimensional Cost Distance

2020 ◽  
Vol 9 (6) ◽  
pp. 353
Author(s):  
Yaqian Chen ◽  
Jiangfeng She ◽  
Xingong Li ◽  
Shuhua Zhang ◽  
Junzhong Tan
Keyword(s):  
Data Structures ◽  
Geographical Information Systems ◽  
Three Dimensional ◽  
Hash Table ◽  
Geographical Information ◽  
3D Space ◽  
Cost Distance ◽  
Efficient Calculation ◽  
Efficient Data ◽  
The Cost

Cost distance is one of the fundamental functions in geographical information systems (GISs). 3D cost distance function makes the analysis of movement in 3D frictions possible. In this paper, we propose an algorithm and efficient data structures to accurately calculate the cost distance in discrete 3D space. Specifically, Dijkstra’s algorithm is used to calculate the least cost between initial voxels and all the other voxels in 3D space. During the calculation, unnecessary bends along the travel path are constantly corrected to retain the accurate least cost. Our results show that the proposed algorithm can generate true Euclidean distance in homogeneous frictions and can provide more accurate least cost in heterogeneous frictions than that provided by several existing methods. Furthermore, the proposed data structures, i.e., a heap combined with a hash table, significantly improve the algorithm’s efficiency. The algorithm and data structures have been verified via several applications including planning the shortest drone delivery path in an urban environment, generating volumetric viewshed, and calculating the minimum hydraulic resistance.

A Constrained Delaunay Triangulation Algorithm Based on Incremental Points

2011 ◽  
Vol 90-93 ◽  
pp. 3277-3282 ◽  
Author(s):  
Bai Chao Wu ◽  
Ai Ping Tang ◽  
Lian Fa Wang
Keyword(s):  
Information System ◽  
Data Structures ◽  
Delaunay Triangulation ◽  
Spanning Tree ◽  
Minimum Spanning Tree ◽  
Three Dimensional ◽  
Geographical Information ◽  
Two Dimensional ◽  
Data Set ◽  
Constrained Delaunay Triangulation

The foundation ofdelaunay triangulationandconstrained delaunay triangulationis the basis of three dimensional geographical information system which is one of hot issues of the contemporary era; moreover it is widely applied in finite element methods, terrain modeling and object reconstruction, euclidean minimum spanning tree and other applications. An algorithm for generatingconstrained delaunay triangulationin two dimensional planes is presented. The algorithm permits constrained edges and polygons (possibly with holes) to be specified in the triangulations, and describes some data structures related to constrained edges and polygons. In order to maintain the delaunay criterion largely，some new incremental points are added onto the constrained ones. After the data set is preprocessed, the foundation ofconstrained delaunay triangulationis showed as follows: firstly, the constrained edges and polygons generate initial triangulations，then the remained points completes the triangulation . Some pseudo-codes involved in the algorithm are provided. Finally, some conclusions and further studies are given.

scholarly journals Calculate Accurate 3D Cost Distance Efficiently

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Yaqian Chen ◽  
Jiangfeng She ◽  
Xingong Li
Keyword(s):  
Data Structure ◽  
Distance Function ◽  
Friction Surface ◽  
Hash Table ◽  
Route Planning ◽  
Weighted Interpolation ◽  
Cost Distance ◽  
Distance Weighted ◽  
Cost Paths ◽  
The Cost

<p><strong>Abstract.</strong> Cost distance is one of the fundamental functions in geographic information systems (GIS), which has been used in various applications such as route planning, construction of Thiessen polygons and distance weighted interpolation. Conventional 2D cost distance function, due to its limited movement directions (either 4 or 8 neighbourhood cells) in the raster data model, overestimates the least cost and the problem is especially severe with a homogeneous friction surface. 3D cost distance function removes the limitation that movement must occur on a planar surface. It can therefore take into account tunnels and bridges when calculating least cost paths. In addition, it can also be used in many other application domains which deal with 3D geospatial data such as in atmospheric science, geology, and oceanography. Based on the method in Tomlin (2010), which can completely eliminate the overestimation when traveling on a homogeneous friction surface, this research proposes an algorithm that calculates accurate least cost with both homogeneous and heterogeneous friction in 3D space. When extending the cost distance function from 2D to 3D, the number of voxels in the propagation front increases significantly and efficiency is an imperative issue. This research also improves the computational efficiency by developing a data structure that combines a binary heap and a hash table. Our results show that the proposed algorithm can calculate accurate 3D cost distance in a homogeneous friction space, and the proposed data structure (i.e., heap plus hash table) not only significantly reduces the algorithm’s runtime but also benefits more in 3D than in 2D. In addition, we have applied the method in a 3D drone delivery routing application in a city environment (Figure 1). Additional applications, such as calculating groundwater flow paths of least hydraulic resistance in a heterogeneous 3D hydraulic conductivity field, are currently under development.</p>

scholarly journals Applying Standard Digital Map Data in Map-aided, Lane-level GNSS Location

2015 ◽  
Vol 68 (5) ◽  
pp. 827-847 ◽  
Author(s):  
David Bétaille ◽  
François Peyret ◽  
Maxime Voyer ◽  
Keyword(s):  
Measurement Errors ◽  
Geographical Information Systems ◽  
Three Dimensional ◽  
Total Duration ◽  
3D Models ◽  
Geographical Information ◽  
Line Of Sight ◽  
Geometrical Modelling ◽  
Median Error ◽  
Map Data

Urban positioning using the Global Positioning System (GPS) is challenging because of multipath. Urban canyons limit open sky visibility, and cause signal reflection and diffraction, resulting in significant satellite range measurement errors. The investigations reported here have been carried out in a French project calledInturb(an acronym derived from integrity and urban positioning). So far, the project has had two phases: first, a simple Three-Dimensional (3D) geometrical city modelling, called “Urban Trench”, has been developed and engineered manually from data sets collected in different cities. Positioning improvement in terms of accuracy was quantified where the model could be applied. Second, this modelling has been automated, based on the standard national BD Topo ® map database for France, with promising results. This geometrical modelling makes it possible to distinguish between line-of-sight satellite signals and those from non-line-of-sight. The latter, apparentlybona fide, signals are caused by strong reflections, usually from buildings with a lot of steel and glass in their construction. A correction of the pseudo-range measurements of the latter is also computed and applied in the position estimator. Positioning accuracy is improved, whilst availability is kept at its maximum. In the study both manual and automatic 3D models are used in extensive experimental campaigns. Results are: first, the possibility to cover entirely any urban area in the country; second, the reduction of the median error in 3D by more than 50% on data collected in Nantes, Paris and Toulouse for a total duration of nearly ten hours; third, the compliance with standards used in most embedded maps and geographical information systems, including an assessment of the trade-off between the model simplicity and the positioning improvement.

scholarly journals Cartographic Analysis of the Geomorphological Hazards of the Eastern Part of Sheikh Saad Sub-District by Using GIS

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Hind Fadhil Ibrahim Al-Jubouri ◽  
Firas S Raheem ◽  
Prof Dr Osama K Abdulridah ◽  
Prof Dr Ali A Kazem
Keyword(s):  
Information Systems ◽  
Spatial Analysis ◽  
Geographical Information Systems ◽  
High Efficiency ◽  
Geographical Area ◽  
Three Dimensional ◽  
Geographical Information ◽  
3D Analysis ◽  
Automated Methods ◽  
Modern Technologies

Geographical information systems are the latest applied computer technologies that contribute to supporting contemporary geographical studies through the possibility of working on preparing a database of geographical phenomena and modeling them in a digital form by providing automated methods and a set of systems and programs for managing and processing data with spatial and non-spatial reference, which is one of the important functions in geographic information systems And the base on which it depends to reach the optimal decisions to reveal the spatial relationships and correlations between geographical phenomena and with high efficiency, to become the contemporary method in the method of processing and spatial analysis of geographical information instead of the old traditional methods of geographical analysis, and the system also allowed the geographical area to enter into the era of modern technologies to evaluate phenomena. Geographical forecasting. The research materials and methods are determined by adopting topographical and geological maps, land-sat satellite visuals, and DEM data to form the search database, and based on the GIS program (Arc Map 9.3) and the (Global Mepper 11) program and the extensions of the (Arc Map 9.3) program, which are (Spatial Analysis) And the three-dimensional analysis (3D analysis), and the outputs are the final process through which the results of the research emerge. These outputs show the type of information that will be processed and presented in the form of three-dimensional maps and shapes, studying the most important causes of geomorphological risks for the study area, and developing solutions and treatments through the conclusions and recommendations of the research.

scholarly journals APPLICATION OF GEOGRAPHICAL INFORMATION SYSTEMS IN MODELLING OF MILITARY OPERATIONS

Aviation ◽  
2005 ◽  
Vol 9 (3) ◽  
pp. 36-42 ◽  
Author(s):  
Albertas Pincevičius ◽  
Romualdas Baušys ◽  
Pranas Jankauskas
Keyword(s):  
Information Systems ◽  
Stochastic Model ◽  
Military Personnel ◽  
Geographical Information Systems ◽  
Three Dimensional ◽  
Geographical Information ◽  
Military Operations ◽  
Random Functions ◽  
Gis Technologies ◽  
Mathematical Expressions

The algorithm of the stochastic model of combat is given in article. Random functions describing the basic processes of combat (movement of military personnel, detection of the enemy, firing and its results, etc.) are recorded. Corresponding mathematical expressions and numerical evaluations are given. Application of Geographical Information Systems (GIS) technologies and three‐dimensional map in planning battle tactics are discussed.

scholarly journals THE SIMULATION OF AN INFANTRY ATTACK USING GEOGRAPHICAL INFORMATION SYSTEMS

Aviation ◽  
2006 ◽  
Vol 10 (3) ◽  
pp. 30-36 ◽  
Author(s):  
Albertas Pincevičius ◽  
Romualdas Baušys ◽  
Pranas Jankauskas
Keyword(s):  
Information Systems ◽  
Geographical Information Systems ◽  
Three Dimensional ◽  
Stochastic Method ◽  
Geographical Information ◽  
Digital Map

An infantry attack over a specific terrain is modeled. A stochastic method described in our previous study is used. In this model, the position of each soldier during the attack is approximately defined by a square [10 × 10 m] on the battlefield. Making use of the possibilities inherent in a three‐dimensional digital map, a visibility matrix is made up, i. e. the indication whether the enemy sees the soldier in a specific case is given.

Visibility Analysis for Three-Dimension Urban Landscape

2012 ◽  
Vol 500 ◽  
pp. 458-464 ◽  
Author(s):  
Chang Lin Yin ◽  
Wen Qiang Xu ◽  
Qing Ming Zhan ◽  
Hong Hui Zhang
Keyword(s):  
Urban Space ◽  
Geographical Information Systems ◽  
Urban Landscape ◽  
Three Dimensional ◽  
Geographical Information ◽  
Three Dimension ◽  
Analysis Model ◽  
Visibility Analysis ◽  
Analysis Models ◽  
The Relationship

The visual sensation is an important factor in urban planning. A computer analysis technology based on the three-dimensional Geographical Information Systems (3DGIS) can be used to measure the visibility in urban space. The principle of sight calculations is introduced at first. The visibility analysis models about terrain and buildings are proposed. In terrain visibility analysis, a method based on projection and elevation interpolation is used to calculate the visibility of two points. And in building visibility analysis, another projection method is proposed to judge the relationship between the sight and building. Based on the visibility analysis of two points, an approximate visual field in a plane can be computed in a discrete way. The visibility analysis models are proved to be feasible. Further research that combines the visibility analysis model and the quantitative planning targets is suggested.

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