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WHAT IS GIS?

WHAT IS GIS?. By Okan Fistikoglu. DEFINITION. Geographical Information Systems (GIS) are the systems that store, retrieve, analyze, transform and display geo-coded spatial and attribute data. What is geo-coded data?. GEOCODED DATA =Geodata. Position (x,y,z) Shape Type (Point, Line, Polygon)

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WHAT IS GIS?

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  1. WHAT IS GIS? By Okan Fistikoglu

  2. DEFINITION Geographical Information Systems (GIS) are the systems that store, retrieve, analyze, transform and display geo-coded spatial and attribute data. What is geo-coded data?

  3. GEOCODED DATA=Geodata • Position (x,y,z) • Shape Type (Point, Line, Polygon) • Relation to others (Topology) • Thematic Content (Indicated Info) SPATIAL DATA ATTRIBUTE DATA

  4. GEOCODED DATA=Geodata more examples?

  5. COMPONENTS OF A GIS Geographical Information Systems have three important components, • computer- hardware • sets of application software modules • a proper organizational context. These three components must be in balance if the system is to function satisfactorily.

  6. COMPONENT-1 computer- hardware DISC DRIVER DIGITIZER SCANNER C.P.U. TAPE DRIVER SCREEN PLOTTER

  7. Data Input Query Input Geo Database Display and Reporting Transformations COMPONENT-2 application software The software package for geographical information system consists of five basic technical modules.

  8. Data Input Sensors Existing maps Observations Scanners Query Input Geo Database Magnetic media Interactive terminal Digitizers Text files Display and Reporting Transformations DATA INPUT COMPONENT-2 application software

  9. Input Data Input GEOGRAPHIC DATABASE Position Topology Attributes Management System Transinformation Retrieval Query Input Query Input Geo Database Display and Reporting Transformations COMPONENT-2 application software

  10. Data Input DISPLAY AND REPORTING Query Input Geo Database Visual Display terminal Magnetic media Plotter Printer Display and Reporting Transformations MAPS TABLES FIGURES COMPONENT-2 application software

  11. Data Input TRANSFORMATION Maintenance Query Input Geo Database Utilization and Analysis Display and Reporting Transformations COMPONENT-2 application software

  12. Management Aims and Queries from management Information for Management Geographical Information System Data Gathering COMPONENT-3 organizational contex

  13. TYPE OF GEODATA REMEMBER!!! • Position (x,y,z) • Shape Type (Point, Line, Polygon) • Relation to others (Topology) • Thematic Content (Indicated Info) SPATIAL DATA ATTRIBUTE DATA

  14. ATTRIBUTE DATA(Thematic Content) Type Permisible Operations Examples • Alfanumeric Value • (String) =  “Okan Fistikoglu” “1. Kordon Street” “Forest” • Numeric Value  ≤ ≥       Birth “1971” No. “256” Percent “35”

  15. SPATIAL DATA Position Shape Topology Types X, Y, Z coordinates of the data Point, Line, Polygon Positional relation of the data to the others NEW Vector, Raster

  16. STRUCTURE OF SPATIAL DATA • Analysis of attributes and their interactions within the region investigated can be performed using two different approaches. These two approaches determine the process of data collection, data manipulation, and consequently, determine the Structure of Spatial Data. Accordingly, there are two types of structures: • vector structure • raster or grid structure. VECTOR RASTER

  17. VECTOR STRUCTURE POINT Y X

  18. VECTOR STRUCTURE 3 1 4 2

  19. VECTOR STRUCTURE 0 3 1 2 4 1 2

  20. 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 3 4 0 4 0 4 0 0 0 5 0 0 0 0 0 0 0 0 0 0 4 0 4 0 4 0 0 0 4 0 4 5 0 5 4 0 4 5 0 0 0 4 0 0 4 4 0 0 0 4 0 0 0 0 0 5 0 0 0 5 0 0 0 0 0 0 POINT LINE POLYGON RASTER STRUCTURE 4=FOREST 5=URBAN 3=WELL 4=ROAD WIDTH

  21. VECTOR vs RASTER Some major strengths and limits of vector and raster structures.

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