Lockheed Martin-built GPS satellites to participate in civil navigation capability tests

Lockheed Martin-built GPS satellites already in orbit are set to take part in testing of a new L2C signal civilian navigation message (CNAV) capability this summer, which is expected to boost the GPS navigation service globally.

The US Air Force Space Command had announced its plans in March to commence formal testing of the modernised CNAV capability on the operational GPS satellites.

Tests will be conducted to ensure enterprise-level readiness to operate, broadcast and receive civil navigation messages using L2C and L5 signals before the Next-Generation Operational Control System (OCX) is deployed in mid-2016.

A major step in the Air Force’s GPS modernisation programme, the CNAV capability tests are crucial in understanding control segment capabilities, operational procedures, space vehicle (SV) capabilities and user equipment design.

Lockheed Martin Military Space Operations, Sustainment and Logistics director Bill Meersman explains that the tests using the modernised CNAV data on L2C, as well as separate trials of the modernised military navigation message (MNAV) data on L1M and L2M, were conducted in several phases since the first Lockheed Martin Block IIR-M SV launched in 2005.

"The Lockheed Martin GPS Block IIR-M SV and our operations support team at Schriever AFB CO, stand ready to support these new modernised capabilities in service to the global users," Meersman said.

The GPS IIR satellites in orbit include most of the modernised SVs and will play a crucial role in the formal testing.

Launched first in 1997, GPS Block IIR satellites were built in collaboration with Lockheed’s primary navigation payload subcontractor ITT/Exelis.

Designated as IIR-MSVs, the final eight satellites delivered were improved and modernised versions of the initial IIR vehicles, as it could include a new civilian signal L2C and two new military signals, L1M and L2M.

In early 2009, one of the upgraded satellites was also crucial in retaining the US signal frequency allocation for the new civilian L5 signal when it first broadcast at that frequency.

Accounting for almost two thirds of the on-orbit GPS constellation, the IIR and IIR-M SVs currently support billions of global users.

---

Image: The formal testing of the modernised CNAV capability on the operational GPS satellites will be conducted this summer. Photo: file image.