GPS News  
GPS NEWS
GPS Not Working A Shoe Radar May Help You Find Your Way

File image.
by Staff Writers
Raleigh NC (SPX) Dec 06, 2010
The prevalence of global positioning system (GPS) devices in everything from cars to cell phones has almost made getting lost a thing of the past.

But what do you do when your GPS isn't working? Researchers from North Carolina State University and Carnegie Mellon University (CMU) have developed a shoe-embedded radar system that may help you find your way.

"There are situations where GPS is unavailable, such as when you're in a building, underground or in places where a satellite connection can be blocked by tall buildings or other objects," says Dr. Dan Stancil, co-author of a paper describing the research and professor and head of NC State's Department of Electrical and Computer Engineering. "So what do you do without satellites?"

One solution is to use inertial measurement units (IMUs), which are electronic devices that measure the forces created by acceleration (and deceleration) to determine how quickly you are moving and how far you have moved.

The technology works in conjunction with GPS, with the IMU tracking your movement after you lose a GPS signal - and ultimately providing you with location data relevant to your last known location via GPS.

For example, if you entered a cave and lost your GPS signal, you could use the IMU to retrace your steps to the last known GPS location and find your way back out.

However, IMUs have traditionally faced a significant challenge. Any minor errors an IMU makes in measuring acceleration lead to errors in estimating velocity and position - and those errors accumulate over time.

For example, if an IMU thinks you are moving - even as little as 0.1 meters per second - when you are actually standing still, within three minutes the IMU will have moved you 18 meters away from your actual position.

But, "if you had an independent way of knowing when your velocity is zero, you could significantly reduce this sort of accumulate error," Stancil says.

Enter the shoe radar.
"To address this problem of accumulating acceleration error, we've developed a prototype portable radar sensor that attaches to a shoe," Stancil says.

"The radar is attached to a small navigation computer that tracks the distance between your heel and the ground. If that distance doesn't change within a given period of time, the navigation computer knows that your foot is stationary."

That could mean that you are standing still, or it could signal the natural pause that occurs between steps when someone is walking. Either way, Stancil says, "by resetting the velocity to zero during these pauses, or intervals, the accumulated error can be greatly reduced."

In other words, the navigation computer compiles data from the shoe radar and the IMU and, by incorporating the most recent location data from GPS, can do a much better job of tracking your present location.

The paper, "A Low-Power Shoe-Embedded Radar for Aiding Pedestrian Inertial Navigation," is published in the October issue of IEEE Transactions On Microwave Theory And Techniques. The leader author of the paper is Dr. Chenming Zhou, who did the work while a postdoctoral research associate at CMU.

Co-authors are Stancil, and CMU's Dr. Tamal Mukherjee and James Downey. The work was supported, through CMU, by the Air Force Research Laboratory and the Defense Advanced Research Projects Agency. This release is approved for public release, distribution unlimited.



Share This Article With Planet Earth
del.icio.usdel.icio.us DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook



Related Links
Carnegie Mellon University (CMU)
GPS Applications, Technology and Suppliers



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


GPS NEWS
GPS Satellite Achieves 20 Years On-Orbit
Los Angeles AFB CA (SPX) Dec 02, 2010
The Global Positioning System (GPS) constellation is the most robust and capable system in the history of space. Space Vehicle Number (SVN) 23 is a testament to how the Air Force continues to meet and exceed its operational requirements with GPS. GPS Block IIA-10 (SVN-23), built by Boeing (formerly Rockwell Corporation), was launched on 26 November 1990 and set healthy to navigation and ti ... read more







GPS NEWS
Farmers Slowed Down By Hunter-Gatherers As Ancestors Fought For Land

Rains will not stop bumper Australian crop: forecaster

Climate change may mean new crop strategy

India Launch Of Food Security Report Focuses On Rice

GPS NEWS
High Performance Infrared Camera Based On Type-II InAs GaSb Superlattices

World's Fastest Camera Takes A New Look At Biosensing

Manufacturing Made To Measure Atomic-Scale Electrodes

Short Light Pulses Will Enable Ultrafast Data Transfer Within Computer Chips

GPS NEWS
Hong Kong's Cathay Pacific names new chief, eyes China

Iran upset over EU refusal to refuel its airplanes

Cathay Pacific chief nominated to take helm of IATA

Rolls-Royce troubled by engine blowout

GPS NEWS
China's Geely to sell cars online

Volvo, Geely in China plant talks

Nissan sets December 20 launch date for electric Leaf

Can Lima unclog its traffic nightmare?

GPS NEWS
Chile sets terms for Bolivia sea corridor

Brazil's Vale to start trading in Hong Kong

US lawmakers press China on trade disputes

Chase for India's rural rupee inspires tech innovations

GPS NEWS
Burnt Israel forest faces long recovery: experts

Climate talks eye deforestation pact

Ca. 'Ghosts of the Forest' studied

American west's forests face troubling carbon trend

GPS NEWS
Snow From Space

ASU Researcher Uses NASA Satellite To Explore Archaeological Site

Google to pay couple one dollar for trespassing

Mapping Mangroves By Satellite

GPS NEWS
Slovak lawmakers slap 80 percent tax on carbon credit sales

How To Soften A Diamond

Pink diamond sold for 23 million US dollars at auction

Carbon price by 2011, Australia chief says


The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement