1 / 32

Vector* Data Sources

Vector* Data Sources. * mostly. [Georgian’s] First Law of GIS. Try to use somebody else’s data before you even think of generating your own. Geographic data portals. “Be aware” of their existence, but don’t memorize details! Bear in mind while working on your course project.

marika
Download Presentation

Vector* Data Sources

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Vector* Data Sources * mostly CS 128/ES 228 - Lecture 9a

  2. [Georgian’s] First Law of GIS Try to use somebody else’s data before you even think of generating your own CS 128/ES 228 - Lecture 9a

  3. Geographic data portals “Be aware” of their existence, but don’t memorize details! Bear in mind while working on your course project CS 128/ES 228 - Lecture 9a

  4. Nat. Geospatial Data Clearinghouse • Composed of many federal agency reps. • Developing the National Spatial Data Infra-structure • Working with Office of Homeland Security CS 128/ES 228 - Lecture 9a

  5. USGS: National Mapping Info. • Primary responsibility for US mapping • Mapping standards and metadata • Topographic maps • GNIS CS 128/ES 228 - Lecture 9a

  6. US Bureau of the Census • Address and population data, tied to the census tract • TIGER maps CS 128/ES 228 - Lecture 9a

  7. NYS GIS Clearinghouse Familiar site? • Statewide aerial photographs • DOT maps • Gateway to many USGS & NYS products CS 128/ES 228 - Lecture 9a

  8. Academic sites Prominent GIS programs: • Cornell U. • U. Buffalo • U. Calif., SantaBarbara • U. Minnesota CS 128/ES 228 - Lecture 9a

  9. Commercial sites (i.e. $$) CS 128/ES 228 - Lecture 9a

  10. ESRI’s site • nice move, licensing GIS.com!) • The GIS portal!~ 100 GIS links • GIS World CS 128/ES 228 - Lecture 9a

  11. 1. Digital Raster graphs (DRGs) • Scanned topographic maps at various scales • Resolution: 400 dpi typical • Projection and coordinate system: varies (read the metadata!) • Accuracy: roughly that of paper source maps • Layers: either 1 or 2. No full GIS capability CS 128/ES 228 - Lecture 9a

  12. Commercial sources of DRGs Various companies(e.g., Delorme, Silva) • 1:24,000 or 1:100,000 • ~ $100/state • various tools, but one layer CS 128/ES 228 - Lecture 9a

  13. 3-D renderings CS 128/ES 228 - Lecture 9a

  14. USGS DRGs • 1:24,000 or 1:100,000 • two layers - features - topography • feature classes can’t be separated CS 128/ES 228 - Lecture 9a

  15. 2. Digital line graphs (DLGs) • Scales 1:24,000 1:100,000 1:2 million • Full topological data structure (nodes, lines, areas + adjacency information) • Layers: 9 feature classes, street & address information, elevations • Projection: UTM (large & medium scale), Albers Conical Equal Area (small scale) CS 128/ES 228 - Lecture 9a

  16. Olean DLG: roads (4 layers) CS 128/ES 228 - Lecture 9a

  17. Olean DLG: add water features CS 128/ES 228 - Lecture 9a

  18. Olean DLG: add contours CS 128/ES 228 - Lecture 9a

  19. Olean DLG: all layers CS 128/ES 228 - Lecture 9a

  20. How are geographical features represented? Two Mile Creek near campus CS 128/ES 228 - Lecture 9a

  21. Larger rivers: both banks (lines) Allegheny River near campus CS 128/ES 228 - Lecture 9a

  22. Major attribute codes CS 128/ES 228 - Lecture 9a

  23. Minor attribute codes CS 128/ES 228 - Lecture 9a

  24. 3. TIGER maps • U. S. Census Bureau’s DLGformat • Include county,census tract, &census block • De facto standard/source for most commercial geocoding and trip planning software Topologically Integrated Geographic Encoding & Referencing system CS 128/ES 228 - Lecture 9a

  25. The TIGER map browser CS 128/ES 228 - Lecture 9a

  26. Center on a familiar point… CS 128/ES 228 - Lecture 9a

  27. TIGER for Allegany NY CS 128/ES 228 - Lecture 9a

  28. Census Bureau databases • American Factfinder • Reports in table or map form • Joins or relates? CS 128/ES 228 - Lecture 9a

  29. Thematic maps CS 128/ES 228 - Lecture 9a

  30. Resolution to the census tract CS 128/ES 228 - Lecture 9a

  31. Local demographic stats CS 128/ES 228 - Lecture 9a

  32. Summary: digital data sources • Digital raster graphs(DRGs) • Digital line graphs(DLGs) • TIGER files CS 128/ES 228 - Lecture 9a

More Related