Space-based GPS can be handy on your smart phone, in your car, and on a mobile personal navigation device. But a new Australian company says it can boost location accuracy, allowing location devices to pinpoint exactly where you are—to within inches.
According to Technology Review, published by the Massachusetts Institute of Technology, Locata has figured out how to boost location accuracy to exacting levels by essentially mimicking the functions of space-based GPS satellites—but on a much closer and cheaper scale.
Locata's technique is based on adding ground-based "LocataLites"—about the size of hardback books—across a given area. Each device contains a clock and communicates with other nearby LocataLites to ensure that its time is in perfect sync with the others. When a handheld device within the coverage area wants to determine its location, it polls all the nearby LocataLites for its time-based signal. The handheld determines how far away it is from each LocataLite by determining the time differences—mere nanoseconds—of each signal it receives. Using such time differences, the handheld can triangulate its position within the grid of LocataLites.
Since the Earth-based LocataLite stations would be physically closer than the GPS satellites orbiting tens of thousand of miles in space, it would take less time for Locata's signals to reach receivers. More importantly, while GPS satellites use accurate—and pricey—atomic clocks, the Locata boxes user simpler time pieces and existing WiFi technologies for broadcasting. That makes the units much simpler and cheaper to deploy—possibly to areas where traditional GPS service is spotty.
For now, Locata's system will be used for special needs—to track aircraft on the U.S. Air Force's White Sands Missile Range in New Mexico, for example. But next month, Locata plans to work with other companies to build the technology into receivers and as a possible enhancement to devices that already use GPS-based location technology.
Ultrafine Location Fixes: Small ground-based transmitters that mimic GPS satellites help receivers find their position with high accuracy. [Technology Review]