Lockheed Martin Corp said it is working to resolve a technical error disclosed by the US Air Force on Sunday that affected some global positioning system (GPS) satellites but did not degrade the accuracy of GPS signals received by users around the world.

Lockheed said the error involved the ground control system for GPS satellites it runs for the Air Force.

Lockheed spokeswoman Christine Courard said the company had put a "workaround" in place to avoid further errors and was working on a full software correction with the Air Force.

Air Force Space Command said the glitch appeared to involve the ground-based software used to index, or sort, some messages transmitted by GPS IIF satellites built by Boeing Co, but officials were still investigating other possible causes.

Air Force spokesman Andy Roake said the issue came to light in recent days, but archived data showed the problem had gone unnoticed since 2013. He gave no details of the extent of the problem, its impact on the system or how it was discovered.

The Air Force said the problem appeared related to the ground software that builds and uploads messages transmitted by GPS satellites, resulting in an occasional message failing to meet US technical specifications.

Boeing, prime contractor for the GPS IIF satellites, had no immediate comment on the news, which comes days before the Air Force is due to launch the ninth GPS IIF satellite into space.

GPS is a space-based worldwide navigation system that provides users with highly accurate data on position, timing and velocity 24 hours a day, in all weather conditions.

The US military uses the GPS for targeting precision munitions and steering drones. It also has a wide range of commercial applications for the financial sector, farming and tracking shipments of packages. Car navigation systems and mobile phones use GPS to determine their location.

Boeing is under contract to build 12 GPS IIF satellites. The first of the GPS IIF satellites was launched in May 2010. – Reuters