Heathcote Chris
Upcoming SlideShare
Loading in...5
×
 

Heathcote Chris

on

  • 998 views

 

Statistics

Views

Total Views
998
Views on SlideShare
998
Embed Views
0

Actions

Likes
0
Downloads
3
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Heathcote Chris Heathcote Chris Presentation Transcript

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