Heathcote Chris

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Heathcote Chris

  1. 1. 35 ways to find your location Chris Heathcote Product experience manager Orange SA O’Reilly Emerging Technology Conference February 9-12, 2004
  2. 2. why am I here? <ul><li>in 10 years' time, </li></ul><ul><li>there will be </li></ul><ul><li>no concept of lost </li></ul><ul><li>There will come an age in the far-off years When Ocean shall unloose the bonds of things, When the whole broad earth shall be revealed Seneca </li></ul>
  3. 3. where have we come from? <ul><li>the stars, the sun </li></ul><ul><li>reading nature - birds, vegetation, wind direction, ocean swells (Polynesians) </li></ul><ul><li>follow a path or coast </li></ul><ul><li>the compass </li></ul><ul><li>the almanac </li></ul><ul><li>the astrolabe </li></ul><ul><li>the sextant </li></ul><ul><li>accurate clocks </li></ul><ul><li>the map </li></ul><ul><li>local knowledge (bushcraft) </li></ul>
  4. 4. no magic bullet <ul><li>GPS is not the solution </li></ul><ul><li>don't just throw technology at the problem </li></ul><ul><li>appreciate the toolbox </li></ul><ul><li>match needs to methods for you and your users </li></ul>
  5. 5. measures <ul><li>accuracy </li></ul><ul><li>availability </li></ul><ul><li>reliability / trust </li></ul><ul><li>output useful to humans </li></ul><ul><li>output useful to computers </li></ul><ul><li>requirements for conversion (extra enablers needed) </li></ul><ul><li>acquire or refine? </li></ul>
  6. 6. good enough <ul><li>what is good enough for your users? </li></ul><ul><li>how much benefit will they get? </li></ul><ul><li>what will it cost them? - time, money, frustration </li></ul><ul><li>most current consumer applications - 20-50m </li></ul>
  7. 7. 0. assume: The Earth <ul><li>EARTH PIC </li></ul><ul><li>accuracy: ~510 square Megametres </li></ul><ul><li>availability: until we conquer space </li></ul><ul><li>requirements: belief in a spherical Earth </li></ul><ul><li>best for: acquiring </li></ul>
  8. 8. <ul><li>the time </li></ul><ul><li>(light, dark, timezones) </li></ul><ul><li>mainly relative position of people </li></ul><ul><li>&quot;It's 3 pm here” </li></ul><ul><li>&quot;It's 7 am here” </li></ul><ul><li>easiest to use when moving long distances </li></ul><ul><li>(these days) </li></ul><ul><li>accuracy: 1000 miles (E-W) n/a (N-S) </li></ul><ul><li>availability: clocks </li></ul><ul><li>requirements: UTC </li></ul><ul><li>best for: seafaring, conf calls </li></ul>
  9. 9. 2-7. cultural clues <ul><li>which cell phone operators available? </li></ul><ul><li>which wi-fi providers? </li></ul><ul><li>phonebox operators? </li></ul><ul><li>phone number syntax? </li></ul><ul><li>newspapers available? </li></ul><ul><li>language being spoken? </li></ul><ul><li>accuracy: 1000 - 100,000 miles </li></ul><ul><li>availability: civilisations </li></ul><ul><li>requirements: up-to-date list of providers/information </li></ul><ul><li>best for: acquiring </li></ul>
  10. 10. 8. ask someone <ul><li>POLICEMAN PIC </li></ul><ul><li>accuracy: 10 metres ........ </li></ul><ul><li>availability: civilisations </li></ul><ul><li>requirements: someone who knows where they are, social interaction, a common language </li></ul><ul><li>best for: refining </li></ul>
  11. 11. 9. use a map <ul><li>maps tell stories </li></ul><ul><li>have to have a map that tells your story </li></ul><ul><li>high cognitive load - getting orientation or locating on a map </li></ul><ul><li>accuracy: 10 metres - 1 mile </li></ul><ul><li>availability: from any good bookstore (good for civilisations) </li></ul><ul><li>requirements: geolocated mapping </li></ul><ul><li>best for: refining </li></ul>
  12. 12. mobile phone location <ul><li>mainly available through network operators </li></ul><ul><li>methods often made invisible to the user and the requester </li></ul><ul><li>just different accuracy </li></ul>
  13. 13. 10. cell ID <ul><li>network reports which cell you are using </li></ul><ul><li>not always connected to nearest cell </li></ul><ul><li>can appear to move as you roam from cell to cell </li></ul><ul><li>Timing Advance </li></ul><ul><li>http://sitefinder.radio.gov.uk </li></ul><ul><li>accuracy: 50 metres - 2 miles </li></ul><ul><li>availability: cell coverage </li></ul><ul><li>requirements: network hooks </li></ul><ul><li>best for: acquiring </li></ul>
  14. 14. 11. cell ID (local lookup) <ul><li>extract cell ID from phone radio stack </li></ul><ul><li>can be used for context (home, work) </li></ul><ul><li>cell IDs reported may not correspond to available data </li></ul><ul><li>proprietary information needed for real geopositioning (or lots of collaborative mapping) </li></ul><ul><li>out-of-date / inaccurate data a problem </li></ul><ul><li>accuracy: 50 metres -5 miles </li></ul><ul><li>availability: wherever there's coverage </li></ul><ul><li>requirements: cell ID to lat/long data </li></ul><ul><li>best for: acquiring </li></ul>
  15. 15. 12. angle of arrival (AOA) <ul><li>detects angle of phone to transmitter </li></ul><ul><li>network could then use more than one transmitter to position </li></ul><ul><li>resolution not always precise </li></ul><ul><li>- can be 45 degrees </li></ul><ul><li>accuracy: 50 metres - 200 metres </li></ul><ul><li>availability: coverage </li></ul><ul><li>requirements: AOA network </li></ul><ul><li>best for: acquiring </li></ul>
  16. 16. 13. time difference of arrival (TDOA) <ul><li>times signal from handset to cell transmitters </li></ul><ul><li>http://www.trueposition.com </li></ul><ul><li>accuracy: 30 metres - 50 metres </li></ul><ul><li>availability: wherever there's coverage (and can find several transmitters) </li></ul><ul><li>requirements: network hooks, TDOA-enabled network </li></ul><ul><li>best for: acquiring </li></ul>
  17. 17. 14. observed time difference (OTD) <ul><li>phone times differences </li></ul><ul><li>between receiving signals </li></ul><ul><li>phone passes data to </li></ul><ul><li>network for analysis </li></ul><ul><li>accuracy: 25 - 250 metres </li></ul><ul><li>availability: coverage </li></ul><ul><li>requirements: OTD handsets/network </li></ul><ul><li>best for: acquiring </li></ul>
  18. 18. 15. assisted GPS <ul><li>assistance information produced by cell network </li></ul><ul><li>Simple GPS receiver built into phone handset </li></ul><ul><li>combines with information from one or more GPS satellites </li></ul><ul><li>needs AGPS enabled network </li></ul><ul><li>needs more hardware and software in phone </li></ul><ul><li>accuracy: 10 metres - 50 metres </li></ul><ul><li>availability: wherever there's coverage (and clear view of one GPS satellite) </li></ul><ul><li>requirements: network hooks, AGPS-enabled network, AGPS-enabled phone </li></ul><ul><li>best for: acquiring </li></ul>
  19. 19. geolocation technology
  20. 20. 16. GPS <ul><li>pretty good accuracy - at a cost </li></ul><ul><li>Selective Availability </li></ul><ul><li>can appear to move as satellites appear and disappear </li></ul><ul><li>other systems - GLONASS, LORAN-C, Galileo </li></ul>
  21. 21. GPS contd. <ul><li>needs more technology (though cost is coming down) </li></ul><ul><li>eats battery </li></ul><ul><li>needs clear line of sight to 3 or more satellites </li></ul><ul><li>- cannot be used in a building, let alone in your pocket </li></ul><ul><li>slow (for first fix) </li></ul><ul><li>accuracy: 10 metres - 75 metres </li></ul><ul><li>availability: clear view of three GPS satellites - four for elevation </li></ul><ul><li>requirements: a GPS receiver (and a few dozen satellites) </li></ul><ul><li>best for: acquiring </li></ul>
  22. 22. 17. WAAS and other GPS enhancements <ul><li>improve accuracy using other satellites, or fixed radio stations (EGNOS in Europe) </li></ul><ul><li>reports any foreseen errors in GPS, and corrects </li></ul><ul><li>could be commercialised </li></ul><ul><li>accuracy: 2 metres - 25 metres </li></ul><ul><li>availability: clear view of three GPS satellites + other data sources (satellite, radio) </li></ul><ul><li>requirements: an enhanced GPS receiver (and a few dozen satellites) </li></ul><ul><li>best for: acquiring </li></ul>
  23. 23. 18. differential GPS <ul><li>two receivers pretty close to each other (~200km) </li></ul><ul><li>signals have had same atmospheric errors </li></ul><ul><li>reference receiver is very accurately located </li></ul><ul><li>transmits errors in location to roving receiver </li></ul><ul><li>accuracy: 1-3 metres </li></ul><ul><li>availability: clear view of three GPS satellites at two locations (and communications between) </li></ul><ul><li>requirements: DGPS receivers </li></ul><ul><li>best for: acquiring </li></ul>
  24. 24. street furniture
  25. 25. 19. post codes / zipcodes <ul><li>lookup list from codes to locations </li></ul><ul><li>can be very accurate for positioning </li></ul><ul><li>proprietary data </li></ul><ul><li>goes out of date </li></ul><ul><li>only available when at a computer/phone book </li></ul><ul><li>accuracy: 10 metres to ... miles </li></ul><ul><li>availability: not when mobile </li></ul><ul><li>requirements: postcode database </li></ul><ul><li>best for: acquiring </li></ul>
  26. 26. 20. street names <ul><li>not all countries have street names </li></ul><ul><li>hard to enter when mobile (picking is best) </li></ul><ul><li>not unique </li></ul><ul><li>accuracy: 20 metres to </li></ul><ul><li>hundreds of miles </li></ul><ul><li>availability: pretty good </li></ul><ul><li>requirements: street address lookup </li></ul><ul><li>best for: acquiring or refining </li></ul>
  27. 27. 20a. street corners / intersections <ul><li>high accuracy in built-up areas </li></ul><ul><li>great for motorways </li></ul><ul><li>even provides orientation in US cities (streets and avenues) </li></ul><ul><li>accuracy: 10 metres to 5-10 miles (motorways/&quot;freeways&quot;) </li></ul><ul><li>availability: pretty good </li></ul><ul><li>requirements: street address lookup </li></ul><ul><li>best for: refining </li></ul>
  28. 28. 21. street numbers <ul><li>great - if they're available </li></ul><ul><li>need street name as well </li></ul><ul><li>accuracy: 10-100 metres </li></ul><ul><li>availability: pretty good </li></ul><ul><li>requirements: street number and address lookup </li></ul><ul><li>best for: refining </li></ul>
  29. 29. 22. business names <ul><li>databases go out of date </li></ul><ul><li>hard to enter when mobile </li></ul><ul><li>multiple locations </li></ul><ul><li>accuracy: 10 metres </li></ul><ul><li>availability: good in urban locations </li></ul><ul><li>requirements: business address lookup </li></ul><ul><li>best for: refining </li></ul>
  30. 30. 23. landmarks and littlemarks <ul><li>user picks what they can see </li></ul><ul><li>orientation from large landmarks </li></ul><ul><li>(e.g. skyscrapers) </li></ul><ul><li>maybe from street frontage photos </li></ul><ul><li>accuracy: < 1 mile - as far as the eye can see </li></ul><ul><li>availability: ok in urban locations, depends on </li></ul><ul><li>rural geography </li></ul><ul><li>requirements: landmark database and lookup </li></ul><ul><li>best for: refining </li></ul>
  31. 31. 24-26. phone boxes / public transport stops / utility markings <ul><li>bus stops, fire hydrants, </li></ul><ul><li>street lamps, traffic lights </li></ul><ul><li>proprietary data - but open for </li></ul><ul><li>collaborative mapping </li></ul><ul><li>often localised - to council or area, </li></ul><ul><li>let alone a city </li></ul><ul><li>accuracy: 10 metres </li></ul><ul><li>availability: ok in urban locations </li></ul><ul><li>requirements: access to database </li></ul><ul><li>best for: acquisition </li></ul>
  32. 32. 27. location street signs <ul><li>dedicated street signs for geolocation </li></ul><ul><li>a nice idea in principle </li></ul><ul><li>installed in London by a taxi firm (proprietary) </li></ul><ul><li>http://www.location-net.co.uk/taxipoint/ </li></ul><ul><li>accuracy: 10 metres </li></ul><ul><li>availability: bad </li></ul><ul><li>requirements: installation of street furniture </li></ul><ul><li>best for: acquisition </li></ul>
  33. 33. 28. geowarchalking <ul><li>postcode </li></ul><ul><li>street name </li></ul><ul><li>street numbers </li></ul><ul><li>lat/long graffiti </li></ul><ul><li>spray paint/sticker barcodes </li></ul><ul><li>accuracy: depends </li></ul><ul><li>availability: bad </li></ul><ul><li>requirements: crazy pirate geo-graffiti gangs </li></ul><ul><li>(Marc Smith's 2%) </li></ul><ul><li>best for: acquisition </li></ul>
  34. 34. emerging technology
  35. 35. 29. dead reckoning <ul><li>accelerometers, electronic compasses </li></ul><ul><li>highly accurate reckoning of relative position </li></ul><ul><li>needs an accurate location (and time source) to start with </li></ul><ul><li>accuracy: as good as initial lock </li></ul><ul><li>availability: everywhere </li></ul><ul><li>requirements: accelerometer and decoding </li></ul><ul><li>best for: refining </li></ul>
  36. 36. 30. wi-fi triangulation <ul><li>needs wi-fi nodes with a location server </li></ul><ul><li>needs accurate location of nodes </li></ul><ul><li>ubiquitous wi-fi is an American dream </li></ul><ul><li>used in art galleries and museums </li></ul><ul><li>At this conference - </li></ul><ul><li>http://activecampus2.ucsd.edu/oreilly/ </li></ul><ul><li>accuracy: 5-20m. </li></ul><ul><li>availability: bad </li></ul><ul><li>best for: refining </li></ul>
  37. 37. 31. broadcast TV/radio triangulation <ul><li>needs broadcast reception from three different locations </li></ul><ul><li>not likely in many areas (planning regulations) </li></ul><ul><li>accuracy: 50m </li></ul><ul><li>availability: ok </li></ul>
  38. 38. 32. IP lookup <ul><li>currently uninformative (normally the address of an ISP or reseller) </li></ul><ul><li>some work to make this more dynamic </li></ul><ul><li>accuracy: a country, a continent </li></ul>
  39. 39. location advertising
  40. 40. 33. encoding of location in access point name / location points <ul><li>wi-fi node advertises location through SSID </li></ul><ul><li>need a standard to be useful in more than one network of hotspots </li></ul><ul><li>http://www.orangecone.com/archives/000088.html </li></ul><ul><li>accuracy: 100m </li></ul>
  41. 41. 34. local servers / Rendezvous <ul><li>fixed machines advertise their location through wi-fi </li></ul><ul><li>need a standard </li></ul><ul><li>http://www.headmap.org/ </li></ul><ul><li>accuracy: 100-300m </li></ul><ul><li>35. bluetooth </li></ul><ul><li>accuracy: 1-100m. </li></ul>
  42. 42. 36. RFID <ul><li>RFID card scanned; scanner is geolocated </li></ul><ul><li>or in reverse - card senses if scanned (and potential lookup) </li></ul><ul><li>http://www.starhill.us/mappingsensornets.html </li></ul><ul><li>accuracy: dead - 50m. </li></ul>
  43. 43. a social future
  44. 44. 37. who you are near (inference) <ul><li>people (and people's things) reveal context </li></ul><ul><li>if one of these is geolocated, this could be used by all </li></ul><ul><li>38. objects you are near </li></ul><ul><li>your device asks others around for more-accurate locations </li></ul><ul><li>&quot;phone reports 50m accuracy” </li></ul><ul><li>&quot;wi-fi connected computer nearby reports 10m accuracy by connected GPS” </li></ul><ul><li>&quot;bluetooth node reports 5m accuracy with WAAS” </li></ul><ul><li>either pick what appears to be the most accurate, or aggregate and average the locations </li></ul>
  45. 45. 39. the road most traveled <ul><li>recording and aggregation of accurate flows </li></ul><ul><li>time, speed and quantity of movement </li></ul><ul><li>maps autogenerate themselves </li></ul><ul><li>better directions, even see which direction your friends have been or normally go </li></ul><ul><li>Amsterdam Real Time, http://www.waag.org </li></ul>
  46. 46. a few messages <ul><li>location finding helps fulfill a basic human need - security </li></ul><ul><li>technology helps - but no one technology fulfills every need </li></ul><ul><li>what happens when technology fails? </li></ul><ul><li>electronic acquisition pays no attention to geography - or the way humans think about their location </li></ul><ul><li>choose your weapons carefully </li></ul><ul><li>expect and use more than one method </li></ul><ul><li>what if you want to be lost? </li></ul>
  47. 47. questions? <ul><li>[email_address] </li></ul><ul><li>http://anti-mega.com </li></ul><ul><li>presentation available from: </li></ul><ul><li>http://undergroundlondon.com/etech_35ways.ppt </li></ul><ul><li>http://locative.net </li></ul><ul><li>Geowanking mailing list </li></ul><ul><li>#geo on irc.oftc.net </li></ul><ul><li>hope you had a good ETCon! </li></ul><ul><li>(thanks to Rael and all at O'Reilly) </li></ul>

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