Cursor keeps a radio eye on large sites

A radio-based system for tracking objects around large areas, such as industrial sites, has been developed by Scientific Generics and Cambridge Positioning Systems.

The system, called Cursor, has an accuracy of 3m. It has been developed for tracking ground vehicles around airports, industrial sites, or even animals in wildlife parks.

Cursor monitors the coverage area using three or more beacons installed across the site. The system also includes a master location computer with user interface and small, inexpensive tags.

Each tag periodically emits a low-power microwave radio signal that is picked up by the beacon network. The computer uses a patented interferometry method – using radio wave interference – to calculate position rather than conventional time-of-flight measurements.

Tracking using time of flight involves calculating position based on the time it takes a tag’s signal to reach each beacon. The interferometry method is said to be more accurate.

The system has already been tested at Heathrow airport and around Cambridge. There are as yet no plans to commercialise the technology.