Finding a cell phone under 5 floors of concrete. Put your cell phone in your car. Park 4 or 5 floors down. Go somewhere else and ask your PC where your phone is. When you get to this site click E911 & E211 for some useful E911 resources; click "In Action" to select a cool 5 min video. This is exciting stuff -- and the guy running Global Locate is obviously having fun!
Also from Global Locate, a 2001 paper entitled: "Global Locate Indoor GPS Chipset & Services" by Frank van Diggelen (on ION members site).
ABSTRACT: Indoor GPS, or more precisely High-sensitivity GPS, is a combination of Assisted-GPS (A-GPS) and massive parallel correlation. This paper describes a worldwide reference network that provides assistance data for AGPS receivers, and a GPS chipset that uses a massively parallel architecture, along with the assistance data, to provide unprecedented GPS performance. Both the network and the GPS receiver demonstrate performance improvements of 10× or greater over previous state-of-the-art. The worldwide reference network predicts GPS orbits ten days into the future. The GPS receiver achieves time-to-first-fix of 100 milliseconds, when outdoors, and 2 to 5 seconds when indoors. The receiver can power up, acquire satellites, and get an accurate fix when in the closed trunk of a car, inside office buildings, deep urban canyons, parking garages, or shopping malls. The paper also describes the chipset architecture, and shows how it is unlike any previous GPS receiver. By having enough correlators to observe all possible code delays simultaneously, the receiver removes the old distinction between acquisition and tracking. This makes it possible to integrate weak signals for hundreds of milliseconds, and thus acquire signals hundreds of times weaker than a standard GPS receiver.
GPRS: How important a role? Although GPS is the key enabler of the Location revolution that is beginning to unfold, there are many ancillary and equally critical technologies that will make many applications possible. Companies like DigitalAngel are betting on GPRS as the telecomm component.
What it takes to filter out signal errors. Professor Stefano Panzieri and his colleagues, while studying robot navigation in a parking lot, show what kinds of errors you deal with while a robot is stationary. If you wanted to use GPS to steer a vehicle, you'd have a challange. But this article also reveals a lot about what you need to know to pinpoint a stationary vehicle within a couple of cm. The original source is: S. Panzieri, F. Pascucci, G. Ulivi, “An Outdoor Navigation System Using GPS and Inertial Platform,” IEEE/ASME Trans. on Mechatronics, vol. 7, n. 2, pp. 134-142, 2002, IEEE, USA.
GPS World - Great source site. I rely on this site for information about the entire spectrum of location technologies. Although GPSWorld covers space, ground and user segments, its coverage of space segment news is the strongest I have found. Good place to track (no pun) what is happening to funding and maintenance of GPS or other sister systems in Europe, Russia, Japan.
Very clever application of location to security, here.
[Dorothy] Denning is pioneering a new type of copyright protection, called geo-encryption. It's a big deal in the information security arena, earning her the moniker of "America's cyberwarrior" from Time magazine and stoking the imaginations of everyone from Hollywood movie executives seeking ways to scare off Napster copycats to hospital administrators looking for a safe way to transport patient data across the Internet without fear of privacy breaches.
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