Digital Surveillance Devices?

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Donna Norton
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1 Technology Framework Tracking Technologies Don Mason Associate Director Digital Surveillance Devices? Digital Surveillance Devices? Secure Continuous Remote Alcohol Monitor SCRAM Page 1

2 Location Tracking Not one, single technology Convergence of several technologies Systems for Tracking inventory, livestock, vehicles, or humans Delivering location-based services to wireless devices Current Technologies Cameras (monitoring, surveillance) Bumper beepers Two-way pagers and cellular telephones Geographic Information Systems (GIS) Global Positioning System (GPS) Vehicle event data recorders (EDR) Radio Frequency Identification (RFID) Wireless Local Area Networks (WLAN) 911 and Enhanced 911 (E-911) Our Focus Today Cell phones Networks and how they work Cell site location information (CSLI) Beepers Global Positioning System (GPS) Digital Cameras Page 2

3 Smartphones GPS Digital Cameras Beepers Types of Devices Game systems MP3 Players E-readers Types of Devices Processes Cellular network triangulation GPS trilateration Geotagging Page 3

4 Smartphones Smartphones Over 5.7 billion cell phones worldwide 327 million in US 103% of population 1.6 billion smartphones sold in 2010 alone Mobile / Cellular phones Positions of mobile phones can be tracked, even on the move Cell phones register their locations with nearest cellular towers, approx every 7 sec s Nearby antenna towers / base stations pick up signals, roam phone to adjacent towers as appropriate Active calls not required (most systems) Multilateration based on comparing multiple antenna signal strengths, pattern Page 4

5 Cell Phone Technology Has become important public safety tool Helps find people in trouble While GPS helps people find their way out of trouble Can locate lost or missing persons (or their phones) Even OnStar uses cellular network to communicate with GPS receiver in car Accuracy dependent on base station density More precise in urban areas with more towers Most Towers Tri-directional Cellular Networks Page 5

6 Cellular Networks Cellular Networks Comparing signal strengths Time delays Angles of arrival Three nearest towers Triangulation Page 6

7 Triangulation Cell Site Location Information Mobile switching centers may retain the location information in call detail records At least for a period of time (e.g., 24 hours) Authorities can track subscriber s general movements by following sequence of towers contacted by the phone May also obtain last recorded location before signal or power lost Cell Site Location Information Most useful location information comes from initiation or receipt of a call or text A call data record (CDR) is kept for billing Yield historical account of cell phone s locations Officers may also locate phone in real time while a call is in progress Page 7

8 Enhanced FCC mandate of 95% of phones Locate phone location within 300 meters Within 6 minutes Beepers Beepers Requires tailing Antenna used to track radio signals Up to 5 miles Placed on car or package 1 x2 to 3 x5 Does not store information Page 8

9 Beepers Use beeps and/or lights to indicate Direction (but not very well) Distance GPS GPS Global Positioning System Developed by US government for military purposes Cost unknown, but EU s competing system expected to cost around $25 billion Still operated by the military Page 9

GPS 32 Earth-orbiting solar-powered satellites 24 in operation, plus spares Limited life span about 10 years Equipped with up to 4

10 GPS Three Components Satellites 24 operational, 3 backups Any point on earth can see at least 6 at all times Each knows its distance from the center of the Earth Ground Stations 11 around the globe Receivers Calculate their distance from the satellite GPS Satellites GPS 32 Earth-orbiting solar-powered satellites 24 in operation, plus spares Limited life span about 10 years Equipped with up to 4 atomic clocks Orbits arranged so at least 4 (ideally 6) satellites visible anywhere, any time Send high-frequency, low-power radio signals Page 10

GPS Ground Stations GPS Ten ground stations

updates needed Four large ground-antenna stations

11 GPS Ground Stations GPS Ten ground stations around Earth Monitor satellite signals and collect accuracy measurements Master control station in Colorado Determine if adjustments or updates needed Four large ground-antenna stations Send corrective data and commands to satellites GPS Receiver Page 11

12 GPS Equipped with quartz clocks constantly reset based on time signal from satellites Locate 4 or more (at least 3) satellites Calculate distance to each Use that information to deduce receiver location Using trilateration In three-dimensional space GPS Devices Portable Portable Navigation Devices Vehicle Outdoor Mobile phones Fixed Vehicle Marine Aviation Tracking Trilateration 2-D Signals from 3 satellites Latitude and Longitude 3-D Signals from 4 or more satellites More accurate Lat/Long plus Elevation/Altitude Page 12

13 2-D Trilateration Involves a bunch of difficult calculations Instead of learning that, let s use pictures 2-D Trilateration Detroit 366 miles 2-D Trilateration Detroit 312 miles Richmond Page 13

14 2-D Trilateration Detroit Charleston 388 miles Richmond Nashville 3-D Trilateration 3-D Trilateration Page 14

15 3-D Trilateration 3-D Trilateration 3-D Trilateration Page 15

16 GPS Accuracy is limited by: Earth s atmosphere Weather generally has no effect But doesn t work underwater Structures, Terrain, Foliage Clock errors Gravitational effect on satellite orbits GPS Generally, accurate to 15 meters Receivers use Differential GPS to calculate error Makes measurement accurate to 10 meters, but possibly up to 10 centimeters Assisted GPS (A-GPS) Uses an assistance server to more rapidly or accurately obtain a location Can be used in lieu of a fully functional GPS receiver or can be used to enhance the accuracy of a location If the GPS receiver has trouble determining a location, A-GPS can make a connection using the cell network to send data Page 16

17 Assisted GPS (A-GPS) Many cell phones use A-GPS, cell site triangulation and other technology to determine location Other benefits Uses less battery power Less time to get a fix Better coverage System can be upgraded at network level Assisted GPS (A-GPS) Satellites Phone Company s Receiver Cell Towers Smartphone A-GPS Server GPS Data Data that may be located on the GPS receiver includes: Device information Owner information Waypoints Home location Points of interest (POI) Deleted locations Last fix Routes/Journeys Track logs Favorites Page 17

Digital Cameras Digital Cameras Pictures and video, of course Geotagging Especially in smartphones Geotagging Adds latitude and longitude coordinates to pictures and video Stored in

18 Digital Cameras Digital Cameras Pictures and video, of course Geotagging Especially in smartphones Geotagging Adds latitude and longitude coordinates to pictures and video Stored in metadata; not visible in the image Usually derived from GPS Camera must have a built-in GPS receiver Can also be used with text messages, social networking updates, and blog posts Page 18

19 Geotagging Convergence Page 19

20 Presented by Don Mason Associate Director, NCJRL Page 20

Digital surveillance devices?

Technology Framework Tracking Technologies Don Mason Associate Director Copyright 2011 National Center for Justice and the Rule of Law All Rights Reserved Digital surveillance devices? Digital surveillance