Boeing has completed testing on the US Air Force’s global positioning system (GPS) satellite ground control system.

The operational control system (OCS) will keep the GPS system operational within specified accuracy parameters to perform global civil, commercial and military operations.

The test demonstrated that the selective availability anti-spoofing module (SAASM) software upgrade met all contractual system requirements.

The SAASM is designed to protect GPS receivers from fake satellite signals from adversaries.

At present the software is being tested to verify if it is ready to fly the constellation in the operations suitability test phase. Boeing is now incorporating final changes to make sure the system becomes operational later in 2009.

The air force also completed the first of a series of combined system tests using the using the GPS IIF Space Vehicle 2 on the ground connected to the OCS to verify the OCS and GPS IIF space vehicle work together to perform the GPS missions.