13. So What is GIS??? “A collection of computer hardware, software and procedures that are used to organize, manage, analyze and display geographically referenced datasets.…"

14. Organizing Spatial Data A GIS works with thematic layers of spatial data Answer questions by comparing different layers of data

15. Five Components GIS An integration of five basic components A Procedures

16. Query Analyze StoreDisplay Capture Output GIS Functions

17. Capturing Data 480585.5, 3769234 483194.1, 3768432 485285.8, 3768391 484327.3, 3768565 483874.7, 3769823 Coordinates Paper maps Digital data GPS GIS Data

18. Components of Geographic Data Three general components to geographic information Attributes Geometry Streets Behavior Rules Streets and highways may not intersect

19. Basic Elements of Spatial Data Space –Location in space requires a georeferncing system Time –Location in time Accuracy Data Models and Formats Attributes –System for defining attributes

20. So How Do We Build A GIS?

21. X,Y Reality (A highway) X,Y Rows Columns Data Models Vector formats –Discrete representations of reality Raster formats –Use square cells to model reality

22. Vector Data Points, Lines and Polygons Good for representing discrete objects: buildings roads, etc. Smaller data storage needs

23. Raster Models Good for modeling continuous data Creation of surfaces Modeling interactions between layers Large data storage needs

25. Images & Grids Rows and columns of equal-sized cells –Each cell stores a value –Detail depends on cell size Grids (the ESRI native raster format) Images (TIFF, BMP, SID, JPEG, ERDAS)

26. Spatial Data Formats ArcGIS works with multiple spatial data formats ArcGIS CAD Coverage Geodatabase Shapefile Raster Tables Internet Map Service

27. Which parcels are within 50 feet of the road? Well type Drilled Building owner Smith Soil type Sandy GIS Analysis Functions Proximity Overlay Network

28. Maps Graphs Display Reports

29. DocumentImage Types of Output Internet Paper map GIS Data