Accurately locating people and tracking their movements inside closed spaces has proven to be a daunting technical task. GPS (Global Positioning System) technology, which can be used to determine one's position on the earth to within a few feet, is ineffective inside buildings, where signals from the GPS satellites bounce off walls and other surfaces, degrading their accuracy.
A small number of university, corporate, and government research teams are attempting to develop alternative technologies. With $3 million in funding, to date, from the U.S. Department of Justice's National Institite of Justice, WPI's indoor personnel location and tracking research group is developing technology based on advanced radio and radar technology that can be used to track and locate first responders inside buildings. At the August forum, the WPI team will discuss the significant progress it has made toward solving the technological challenges associated with indoor personnel location.
Other workshop participants will come from companies developing indoor location and navigation technology, including Raytheon, ITT, Acceleron Technologies, and NAVSYS Corporation ( a leader in GPS technology); from the University of Calgary's PLAN (Position, Location, and Navigation) Research Group; and from several federal agencies concerned with indoor location challenges (from finding people trapped in collapsed buildings to locating miners trapped by mine disasters), including the Department of Homeland Security, the National Institute of Standards and Technology, and the National Institute of Occupational Health and Safety.
Researchers in these and other groups are exploring a number of technological solutions to the problem of indoor personnel location and tracking. They include enhanced GPS, in which the signals from GPS satellites are augmented with other positioning information (for example, signals from cell phone towers); inertial navigation and dead reckoning, in which gyroscopes and accelerometers are used to track the direction and distance traveled; and RFID (Radio Frequency Identification) technology, which uses radio transponders worn by individuals and monitoring stations to track the movements of people within buildings.
Each of these technologies has drawbacks. Enhanced GPS is currently unable to achieve the precision required for first responder location (finding a firefighter in the dense smoke inside a burning building, for example, requires a precision of plus or minus 1 foot). Inertial navigation relies on gyroscopes, which must be frequently realigned. RFID systems only work in buildings where monitoring stations have been preinstalled.
WPI's research group has been following a different route, developing a system that employs principles from orthogonal frequency division multiplexing (OFDM), which transmits high-speed data via wired and wireless channels and integrates well in the radio spectrum, along with super-resolution techniques as used in synthetic aperture radar (SAR), which can extract great detail from radar signals.
WPI's first responder locator system will employ transmitters, to be worn by the first responders, that continuously emit customized OFDM signals. Receivers located on emergency vehicles arrayed around a building will detect and decipher the signals. The receivers will use sophisticated, custom-designed algorithms to determine their distance from the transmitters and, by sorting out a multitude of straight-line and reflected signals, determine the exact location of the transmitters in three-dimensional space.
Indoor tests of the technology have demonstrated significant progress toward the team's goal of developing a system that can pinpoint the location of a firefighter or police officer in three dimensions to within about a foot, has a range of 2,000 feet, can track up to 100 people simultaneously, and can display the location of each responder and the path he or she has taken on a graphical display at an incident command center. This information will make it possible to help first responders find the fastest and safest exit from a building in an emergency, and to locate disable responders quickly despite dense smoke or debris.
WPI's team was motivated to begin work on a precision location system after a Dec. 3, 1999, fire in the Worcester Cold Storage warehouse claimed the lives of six Worcester, Mass., firefighters, all of whom died within 100 feet of exits they were unable to see. The technology the team is developing will have other applications, including determining the location of miners and other workers trapped underground. Future enhancements to the technology will make it possible to also monitor the physiological status of first responders.
For more information about the inaugural WPI Indoor Precision Location and Tracking Forum and about the work of WPI's research team, visit www.ece.wpi.edu/Research/PPL/ or call John A. Orr, professor of electrical and computer engineering, at 508-831-5273.
About Worcester Polytechnic Institute
Founded in 1865 in Worcester, Mass., WPI was one of the nation's first engineering and technology universities. WPI's 18 academic departments offer more than 50 undergraduate and graduate degree programs in science, engineering, technology, management, the social sciences, and the humanities and arts, leading to the BA, BS, MS, ME, MBA and PhD. WPI's world-class faculty work with students in a number of cutting-edge research areas, leading to breakthroughs and innovations in such fields as biotechnology, fuel cells, nanotechnology, and information security. Students also have the opportunity to make a difference to communities and organizations around the world through the university's innovative Global Perspective Program. There are more than 20 WPI project centers throughout North America and Central America, Africa, Australia, Asia, and Europe.
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
Published on PsychCentral.com. All rights reserved.