Air Force launches GPS terminal upgrade

New ground stations will leverage jam-resistance signal dubbed M-Code.


 As more sophisticated constellations of navigation aids are deployed to provide greater accuracy and resistance to electronic jamming, DOD procurement efforts are shifting to modernization of the ground stations required to process and display location data.


In an effort to leverage a new secure signal for third generation Global Positioning System called Military Code, or M-Code, the Air Force is moving ahead with an "early use" command and control effort covering current and future GPS satellites. The program, called GPS M-Code Early Use (MCEU), upgrades GPS ground stations to leverage the more powerful signal that also provides new anti-jamming and spoofing defenses. It would also deliver secure access to military GPS signals by U.S. and NATO forces as Russian electronic warfare capabilities advance.


To that end, the Air Force last month awarded a $45.5 million contract to GPS III manufacturer Lockheed Martin to prepare an initial M-Code capability for GPS. Under the contact, the company will upgrade its current operational control system to upload and monitor M-Code signals within the expanding GPS constellation. The initiative covers 20 GPS satellites currently in orbit along with future GPS III satellites scheduled to begin launching in 2018.


The early use initiative is intended to accelerate deployment of the secure M-Code signal that would support testing and fielding of new jam resistant ground stations. Lockheed Martin said the ground station contract includes new hardware and software development. Those systems are scheduled for deployment in 2019 to ground forces supporting the Air Force's GPS constellation.


The anti-jam GPS deployment is among the ongoing efforts to push navigation and other C4ISR signals through an increasingly dense electronic battlefield. Other approaches include "assured" navigation and positioning capabilities when GPS signals can't get through to ground stations. Those and other approaches will be demonstrated at next week's AUSA conference.


The Air Force contract award to Lockheed Martin is a follow up to an earlier M-Code program called Military GPS User Equipment program. Rockwell Collins, which was acquired last month by United Technologies, completed delivery in May of the last batch of M-Code GPS receivers to the Air Force Space and Missile Systems Center.


According to the manufacturer, M-Code can be used with existing signals without interfering with current or future civilian or military user equipment. The new signal is also designed to be autonomous so users can calculate their positions using only M-Code. By contrast, existing GPS signals require more than one signal code.


According to an Air Force overview on M-Code development, the robust signal design provides better jamming resistance, primarily by enabling transmission at much higher power without interference with earlier code receivers. "The M-Code signal also needed to be compatible with prevention jamming against enemy use of GPS," researchers noted.


"The design should provide more robust signal acquisition than is achieved today, while offering better security in terms of exclusivity, authentication, and confidentiality," the overview concluded.