Bug warning for navigation satellite users

Civilian users of the US Air Force-operated satellite global positioning system (GPS), used for global navigation, could experience the equivalent of the millennium bug from 21 August. The Health & Safety Executive this week urged users to take precautionary measures ahead of the date, when the system’s 10-digit binary counter will reset itself to run […]

Civilian users of the US Air Force-operated satellite global positioning system (GPS), used for global navigation, could experience the equivalent of the millennium bug from 21 August.

The Health & Safety Executive this week urged users to take precautionary measures ahead of the date, when the system’s 10-digit binary counter will reset itself to run for another 20 years. The system needs resetting because its 1,024-week cycle capacity has been reached.

The 24 GPS satellites are mainly used for navigation, but the system also provides a clock to synchronise time for many computer applications. Receivers are used in local and wide area networks, cash machines, public utilities, radar networks and cellular phones.

A British space industry source says any GPS rollover problem will mainly affect systems using data from the 14 earliest GPS satellites.

The Ministry of Defence said: `The main problem will be with civilian systems bought more than five years ago’.

These could include hand-held GPS receivers used in fields such as merchant shipping.

The USAF’s Los Angeles space and missile centre said GPS satellites themselves will be unaffected, but is not so confident about non-military GPS receivers and ground equipment.