1 / 22

Local GPS

Local GPS. Group #5 Team Members: Spencer Balogh , Brandon Estle , Owen Smith, Laura Tufts, Chris Weeks. Wednesday 06/01/2011. Introduction. Global Positioning System What it is and how it works Protocol – Data link Layer & Application Layer Android System

annora
Télécharger la présentation

Local GPS

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. Local GPS Group #5 Team Members: Spencer Balogh, Brandon Estle, Owen Smith, Laura Tufts, Chris Weeks Wednesday 06/01/2011

  2. Introduction • Global Positioning System • What it is and how it works • Protocol – Data link Layer & Application Layer • Android System • Data Markup Languages – XML vs. JSON • Google APIs • Developed Android GPS Application • Implementation • Functionality • User Operation

  3. What is GPS? • Global Positioning System • Navigation system based on the 24 U.S. Department of Defense satellite network • Research began after the Cold War and system was fully implemented by 1994 • Official DoD name for GPS is NAVSTAR

  4. GPS Fun Facts! • Each satellite is built to last about 10 years. • Each satellite weighs approximately 2,000 pounds and is 17 feet across • Each satellite if propelled by rocket boosters and runs purely on solar energy • Each satellite orbits earth twice daily 12,000 feet above atmosphere ~7000 mph.

  5. How it works: • Orbits of satellites are distinctively designed to provide accurate data when combined with other satellite locations. Receiver measures time delay between signal transmission and reception to determine distance of each satellite. 3 locks  2D location 4 locks  3D location

  6. How it works: • Satellites transmit high freq. radio signals: • L1 : Civilian applications – 1575.42 MHz • L2 : Military applications – 1227.60 MHz • L3 – L5 under development/not pertinent • Transmitter consumes less than 50 Watts • Date, Time, Status, and Identification Code generally transmitted

  7. GPS Protocol • Standard protocol is NMEA -183 • National Marine Electronics Association • ASCII based, allows for simultaneous one-to-many serial communication • new upgrade- NMEA 2000 sells for ~$325 • Large amount of re-engineered open source GPS protocol software exists now

  8. GPS Protocol -Data Link Layer • 4,800 Bits Per Second • 8 data bits plus one stop bit • No parity bit • No handshake authentication

  9. GPS Protocol -Application Link Layer • ASCII sentence of following format: $GPAAM,A,A,X.X,N,WPTNME*32 • GP = Transmitter Identifier • AAM = Arrival Alarm • A = Arrivel Center Entered • A = Perpendicular Passed • X.X = Circle Radius • N = Nautical Miles • WPTNME = Waypoint Name • *32 = checksum

  10. Android and GPS • With cell service: • Network location – rough • Satellite location – accurate, quick • Without cell service: • Real GPS chip within device • Directly receives satellite signal

  11. Android System Structure • Built on Linux Kernel 2.6 • All applications are Java based • OS supports open development • Many built-in components, libraries, etc

  12. Data Markup Languages:-XML and JSON • These languages facilitate the transfer of data between applications, servers, mobile devices and users. • As far as data encoded goes, these languages are almost equivalent, however there are a few key differences.

  13. XML vs. JSON

  14. JSON in our project: • We retrieve information about nearby locations using a Google ajax query. • Returns a JSON string that includes local points of interest.

  15. Google APIs • We use the Google Maps and Google Search APIs extensively in our project. • We access these through the Location and Maps and SearchManager packages.

  16. The Android Local GPS • Application developed on the Android operating system • Application integrates GPS location and search data to find nearby points of interest

  17. Project Implementation • Application performs the following (in order): • Accepts query from user • Looks up mobile device’s GPS location • Uses data from query and location to perform AJAX search • Receives JSON data from AJAX search • Parses JSON data and creates map and overlay with information extracted from JSON • Allows the user to interact with map

  18. Project Functionality • Goal of project is merely to find local points of interest • Application accepts any string of text as a search • Text is then sent through AJAX search and local points of interest relating to search are displayed on the map • Map also contains information about places of interest such as address and phone number

  19. User Operation • Use is very straightforward • User simply enters a query into the search box and the application returns a map with local points of interest • Traditional map interaction by user like zoom and scroll • Tapping on map markers will display information about point of interest

  20. Operation Example

  21. DEMONSTRATION

  22. Any Questions?

More Related