1. Introduction to GIS GIS/CAD5

16. CAD – Computer Aided Design GIS – Geographic Information System CAD – drawing, editing, construction, project visualisation - 2D and 3D GIS - mostly 2D - mapping, information collection, spatial analyses, interpretation

17. GIS - essential terms Map – consists of layers and symbolisation Layer – set of single-type information - parcels, streets, buildings, contour-lines, … also called as feature class Feature – a single map object - building, pond, … Attribute – a single characteristics of feature - height, area, type, …

18. Map – consists of layers

19. Layers geometryVectorRaster Point Line Polygon Layers in GIS usually can not contain more than one geometry type One GIS layer normally corresponds to one file

20. Feature – single object of a layer GIS feature consists of 2 parts: Layer is represented as TABLE Features is represented as ROW of the table Geometry Attributes

21. Attributes – characteristics of the features Attributes are represented as COLUMNS of the table Geometry Attributes

22. Understanding to Drawings and Layers 1. CAD Drawing = File consists of layers data and other information at one file Drawing (file) Layer Drawing (file) Layer Reference layer

23. Understanding to Drawings and Layers 2. GIS Layer = File Project = (map) File consists of reference to layers information on selection and symbolisation layout graphics (legend, titles, etc.) Layer (file) Project (file) Layer (file) Project (file)

24. GIS data formats Note: SW GIS normally can read CAD files! ESRI Shapefile (SHP) – GIS commercial standard GML – XML based standard (not much supported) ESRI Geodatabase (GDB, MDB) TIN (vector surface) GRID (raster data) GeoTIFF, JPG, PNG, … Rasters must have coordinate system reference!

25. Layers – data sources and storage Files – GIS formats (shapefile, geodatabase file, rasters) – CAD formats (DXF, DWG, DGN) On-line WWW services – Raster services (WMS) – Vector services (WFS) Database tables (Oracle, PostGIS, …)

26. Useful links: http://support.esri.comhttp://support.esri.com – ESRI vendor http://resources.esri.comhttp://resources.esri.com – ESRI vendor http://geoportal.gov.czhttp://geoportal.gov.cz – Czech Geoportal http://geoportalpraha.czhttp://geoportalpraha.cz – Prague Geoportal