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Geographical Information Systems

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Presentation on theme: "Geographical Information Systems"— Presentation transcript:

1 Geographical Information Systems
Doc. Ing. Pavel Hrubeš, Ph.D.

2 Department Transport Telematics
Rehearsal raster vector precision in graphics x v traditional cartography data volume topology computation update continuous space integration discontinuous Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

3 Department Transport Telematics
Vector data models Spaghetti model Topological model (most common) Triangulated irregular network (TIN) Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

4 Department Transport Telematics
Spaghetti data model Polygon Coordinates A (1,4), (1,6), (6,6), (6,4), (4,4), (1,4) B (1,4), (4,4), (4,1), (1,1), (1,4) C (4,4), (6,4), (6,1), (4,1), (4,4) The spaghetti model is the most simple vector data model The model is a direct representation of a graphical image NO explicit topological information 1 5 4 3 2 6 A B C Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

5 Department Transport Telematics
Spaghetti data model Description: direct line for line translation of the paper map (often viewed as raw digital data) Easy to implement, good for fast drawing Storage and searches are sequential, storage of attribute data Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

6 Department Transport Telematics
Topology Branch of mathematics dealing with geometric properties Geometry of objects remain invariant under transformations Neighborhood relationships remain the same Topology is the distinguishing basis for more complicated vector models Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

7 Topological Vector Model
Topological data models are provided with information that can help us in obtaining solutions to common operations in advanced GIS analytical techniques. This is done by explicitly recording adjacency information into the data structure, eliminating the need to determine it for multiple operations. Each line segment, the basic logical entity in topological data structures, begins and ends when it either contacts or intersects another line, or when there is a change in direction of the line. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

8 Topological Vector Model
Each line has two sets of numbers, a pair of coordinates and an associated node number. Each line segment has its identification number that is used as a pointer to indicate which set of nodes represent its beginning and ending. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

9 Topological Vector Model
Polygons also have identification codes that relate back to the link numbers. Each link in the polygon now is capable of looking left and right at the polygon numbers to see which two polygons are also stored explicitly, so that even this tedious step is eliminated. The Topological data model more closely approximates how we as map readers identify the spatial relationships contained in an analog map document. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

10 Topological vector model
Vector Model: Topological Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

11 Topological model for 3D
3D entities nodes, edges, faces, volumes a support entities : rings -, list of edges round the face shells -, list of faces round the volume Pfund, M., 2001, Topologic data structure for a 3D GIS,. Proceedings of ISPRS, Vol.34, Part 2W2, May,. Bangkok, Thailand, pp Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

12 Department Transport Telematics
Node Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

13 Department Transport Telematics
Node Unique coordinates X, Y a Z. It is not possible that two points overlays. In 2D space should be Z coordinate different. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

14 Department Transport Telematics
Edge Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

15 Department Transport Telematics
Edge It is collection two or more vertexes, orientation is done by its order. Edge cant cross another edge. Node has to divide both edges. Edges are connected only in nodes. Faces or rings have to contain it complete. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

16 Department Transport Telematics
Face Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

17 Department Transport Telematics
Face Geometrie of face is defined: Collection of on ore more edges which form the face, Collection of non or more interior points which form the face, Collection of non or more interior nodes which are identical to nodes of appropriate edges. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

18 Department Transport Telematics
Rings Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

19 Department Transport Telematics
Ring Rings are collection of edges which form a face. Each ring is connected to the specified are, one edge should be contained by more rings. Edge, which is inside the face and is connected to the border of face is also contained by the ring. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

20 Department Transport Telematics
Shell Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

21 Department Transport Telematics
Shells Shell is collection of two or more faces Face, which is a border between two volumes is contained by both shells. Shell should contain one face twice, for both orientations of the face. Each face within volume, connected to the border of volume, is contained by shell. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

22 Department Transport Telematics
Volume Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

23 Department Transport Telematics
Volume Volume is 3D object collected from faces. Volume cant cross or overlay another volume. Should have inside a empty space, which is defined by inside faces. Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

24 Department Transport Telematics
Topological links Link Node - Edge Link Node - Face Link Node - Volume Link Edge – Face Link Edge - Volume Link Face - Volume „Floating“ Node and Edge Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

25 Department Transport Telematics
Link Node - Edge Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

26 Department Transport Telematics
Link Node - Face Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

27 Department Transport Telematics
Link Node - Volume Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

28 Department Transport Telematics
Link Edge – Face Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

29 Department Transport Telematics
Link Edge - Volume Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

30 Department Transport Telematics
Link Face - Volume Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

31 „Floating“ Node and Edge
Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics

32 Database implemetation of 3D data model
Czech Technical University in Prague - Faculty of Transportation Sciences Department Transport Telematics


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