System of Systems: GPS III payloads delivered

September 14, 2017  - By

QZS-2 signal analysis, QZS-3 launched

The second satellite of Japan’s Quasi-Zenith Satellite System (QZSS) has started transmitting navigation signals. QZS-2, or Michibiki-2, was launched on June 1, 2017, and joins its predecessor QZS-1 (Michibiki-1), which has been in orbit since September 2010.

Both satellites have been placed into inclined geosynchronous, elliptical orbits, which enable extended satellite visibility periods over Japan and are characteristic features for this regional navigation system.

The third satellite QZS-3 was launched on Aug. 19, 2017, into a geostationary orbit. If all goes according to plan, a fourth satellite in an eccentric orbit will follow by the end of this year and complete the constellation.

Read full analysis here.

GPS Monitor Station Receivers Deployed

Three of six new Lockheed Martin-developed receivers are now deployed at U.S. Air Force monitoring stations  to maintain the accuracy of GPS satellite signals.

In June, the first Monitor Station Technology Improvement Capability (MSTIC) receiver became operational at Cape Canaveral Air Force Station, Florida. Upgrades continued at USAF monitoring stations  at Kwajalein Atoll and Hawaii. These upgrades from early 1990s technology are part of an overall effort to modernize the current GPS ground control system, known as the Architecture Evolution Plan Operational Control Segment.

MSTIC software-defined radio technology replaces legacy receivers’ hardware-based application-specific integrated circuit platform. MSTIC leverages commercial off-the-shelf hardware without the need for custom firmware. Standard interfaces and architecture configurability simplify sustainment and enable MSTIC software to migrate to new hardware platforms as commercial vendors increase processing power, improve reliability and enhance cybersecurity. MSTIC enables remote application of mission-specific software updates to improve performance and enable reception of modernized GPS signals, according to the company.

The three remaining GPS Monitoring Stations will be upgraded with MSTIC receivers by the end of 2017.

The navigation payload before integration into the second GPS III SV, which now is in environmental testing. (Photo: Harris)

GPS III Payloads Delivered

Harris Corporation has delivered the third of 10 advanced navigation payloads to Lockheed Martin. The payloads will increase accuracy, signal power and jamming resistance for  GPS III satellites. They feature a Mission Data Unit (MDU) with a 70-percent digital design that links atomic clocks, radiation-hardened computers and powerful transmitters, enabling signals three times more accurate than those on current GPS satellites. The new payloads also boost satellite signal power, increase jamming resistance by eight times and help extend the satellite’s lifespan.

The payload was integrated into GPS III SV03 over the summer.  The first navigation payload is integrated aboard GPS III SV01, which is in storage awaiting expected 2018 launch.

Harris announced it is in full production and on target to deliver the fourth GPS III navigation payload to Lockheed Martin in fall. Harris is also developing a fully digital MDU for the U.S. Air Force’s GPS III Space Vehicles 11+ acquisition. The new MDU will be demonstrated in fall 2017 and provides even greater flexibility, affordability and accuracy versus existing GPS satellites.

Next GLONASS-M Readied

The Russian navigation satellite GLONASS-M 52 moved from ISS-Reshetnev Company’s assembly plant to the Plesetsk Cosmodrome launch site about 800 km north of Moscow in August. One of the system’s ground spares, it was built more than two years ago and stored awaiting launch. The satellite is due to launch in September.

There are six GLONASS-M satellites in ground reserve.

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