1 / 28

Network Analysis

Network Analysis. By Josh Bundick EVSC 468 – Advanced GIS March 27, 2003. Agenda. Network Analysis – What is it? What are the tools needed? What do the tools do? How can they help me? How do they work? Demos Conclusions. What is a network?.

winslow
Download Presentation

Network Analysis

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. Network Analysis By Josh Bundick EVSC 468 – Advanced GIS March 27, 2003

  2. Agenda • Network Analysis – What is it? • What are the tools needed? • What do the tools do? • How can they help me? • How do they work? • Demos • Conclusions

  3. What is a network? Any system of interconnected linear features

  4. What is network analysis? • Solving problems involving networks • Goal is efficiency – Saving time and money

  5. What tools are needed? • Network data (connectivity is needed) • Network analysis software – A GIS!

  6. What part of the GIS do I use? • Workstation Arc/Info – “Old School,” command line - driven • ArcView 3.x Network Analyst Extension - Menu – driven and much more user friendly • Currently, ArcGIS 8.x Network Analyst is in developmental stages

  7. What do the tools do? • Direct path analysis • Optimum routing • Closest facility analysis • Drive time analysis • Driving directions

  8. How can this help me? • Direct path: Finding the shortest path between your house and a friend’s • Optimum routing: Helping a pizza deliveryman visit numerous houses in the most time – efficient manner • Closest facility: Finding the closest hospital to an automobile accident

  9. How can this help me? • Drive time analysis: Helping a store determine how many customers are within 5 driving miles • General driving directions: Don’t we all love Mapquest!

  10. How do they work? • Activate Network Analyst extension

  11. How do they work? 2. Add network data

  12. How do they work? 3. All network functions can then be accessed

  13. However………… • If street driving directions are desired, geocoding service must be activated

  14. More “how tos” • To perform analysis, “stops” must be located on or near the network data • These “stops” can be selected interactively, by manually entering addresses, or by loading a “stops” layer

  15. Interactive selection

  16. Manually entering address

  17. Loading a “stops” layer

  18. How does it determine the best routes? • Network Analyst relies on “impedances” • Default impedance is line length • Can also be others, such as estimated travel time • Values must be in attribute table and specified before analysis

  19. Sample calculation • If you know line length and speed limit, a travel time can be estimated 5 mile street/30 miles per hour speed limit * 60 min/hr = 10 minutes

  20. How does it determine the best routes? • One way streets-can be specified in attribute table (must specify allowed travel direction) • Prohibited turns-can be specified in turntable (very tedious procedure) • Under/Overpasses-can be specified in attribute table (add elevation fields)

  21. Now let’s really see what kind of damage we can do with this stuff!

  22. Demo – Direct paths

  23. Demo – Optimum routing

  24. Demo – Closest facility

  25. Demo – Service area

  26. Demo – “Mapquest” directions

  27. Conclusions • Network analysis can be performed fairly easily with ArcView 3.x Network Analyst • However, to be accurate, lots of time must be spent in data preparation • Could become more powerful and user-friendly with customization via Avenue programming • All in all, it’s a very useful tool but it is not cheap!

  28. Any Questions?

More Related