web-based mapping of real-time gis data
TRANSCRIPT
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Web-Based Mapping of Real-Time GIS Data
Cristian Gadea
Network Computing and Control Technologies (NCCT) Lab
University of Ottawa
Presented at Carleton UniversityNov 16, 2007
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Agenda
• Classic Web-Based Maps
• Web 2.0 Maps and Mashups
• OGC Standards Organization & WMS
• OpenLayers
• Real-Time GPS Data
• Other Real-Time Data
• Challenges
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Early Web-Based Maps
• Interactive, affordable & easy to access
• Mapquest– launched in 1996– still the most popular map site today
• 50M monthly visitors vs. 30M for Google Maps
Source: http://www.techcrunch.com/2007/10/12/exclusive-mapquest-plays-catch-up-with-launch-of-beta/
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Joint Intelligence Picture (JIP)
• Information for decision-making
Search for Locations
Show and Hide Map Layers
Receive Information on
Selected Targets
Look up Additional Information
View Detailed Military Maps
Use Advanced Map Controls
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Web 2.0 and Maps
• AJAX (Asynchronous JavaScript and XML) for dynamic webpage updates
• Google/Yahoo/Microsoft “Slippy Maps”• Mashups
– http://www.weatherbonk.com/weather/summary.jsp
– http://www.flickr.com/photos/shreck/map/
• Weather, traffic, and other sensor data not truly mapped in real-time
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Real-Time Data
• “you may not use Google Maps with any products, systems, or applications installed or otherwise connected to or in communication with vehicles, capable of vehicle navigation, positioning, dispatch, real time route guidance, fleet management or similar applications.”Source: http://www.google.com/intl/en_ALL/help/terms_local.html
• Also no control over map images (ex: change colour of parks or host on own server)
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Open Geospatial Consortium (OGC)
• International organization with 330+ members
• Define standards for geospatial content and services (Geographic Information System data processing etc.)
• Web Map Service (WMS)– Easy to host own map images (GeoServer)– Many public WMS servers exist (NASA etc.)– Request tiles (jpg, gif, png) via URL
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OpenLayers
• Free Open Source “slippy map” API• Fast and flexible JavaScript code that can
host on own web server• Compatible with all major desktop browsers
and many mobile browsers
(no plugins necessary)• Supports many types of layers, including
custom WMS layers and maps from Google/Yahoo/Virtual Earth
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Real-Time GPS Data• GPS user sends updates to web server via
wireless internet connection• All clients receive updated GPS information
from web server
Web Server
HTML/AJAX
HTML/AJAX
HTML/AJAX
Laptop with GPS receiver and internet access
Smartphone with integrated GPS and data plan
Other PC User
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Video of Multi-Car GPS
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Better Real-Time Data
• Multi-car animation used pre-recorded GPS data stored on web server
• How can we prove GIS data appears in real-time?
• Microsoft Flight Simulator
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Real-Time Information Infrastructure
Web Server
Flight Data
HTML/AJAXFlight Data
Flight Data
WMS Servers
HTML/AJAX
PC User with Web Browser
Three Flight Simulator Sessions with Data Drivers
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Video of Flight Simulator Data
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Challenges
• JavaScript browser compatibility issues• Customizations for mobile browsers• JavaScript memory management causes
browser to slow down over time• So far only plotted points – for example,
real-time oil spill data best animated with round objects in SVG or Adobe Flash
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Thank you!
• Services discussed:– mapquest.com– maps.google.com– maps.yahoo.com– maps.live.com– weatherbonk.com/weather/summary.jsp– flickr.com/photos/shreck/map/– opengeospatial.org– openlayers.org
• Questions?