The Air Force is looking at potential warfighter use of international space-based position, navigation and timing (PNT) systems, the head of its space forces said Feb. 7.

Air Force Space Command (AFSPC) chief Gen. William Shelton said commercial PNT receivers being developed now are almost “system agnostic,” meaning they will be able to be used on other nations’ systems. For global constellations, the United States has Global Positioning System (GPS), the European Union has Galileo, Russia has its Global Navigation Satellite System (GLONASS) and China has Beidou. There is also a regional constellation in India’s Regional Navigational Satellite System (IRNSS) while Japan is building its own constellation.

“We will likely get to a place where commercial manufacturers are producing those kinds of capabilities (and) tacking on M-code (military code) to that,” Shelton said at a Capitol Hill breakfast hosted by the Air Force Association’s (AFA) Mitchell Institute. “We’ll see where that goes, but yes, it’s very much in the discussion.”

PNT systems like GPS are also generally known as Global Navigation Satellite Systems (GNSS), which typically consist of three segments: satellites orbiting the earth, stations on the ground to track and monitor the satellites and users who rely on the satellites to compute their position and motion, according to Hemisphere GNSS

, which designs and manufactures GNSS and complementary products for positioning, guidance and machine control applications. A GNSS receiver knows where each satellite is on orbit and compares it with the time required to receive each satellite’s signal. The receiver uses these measurements to calculate its specific position on earth.

Trimble [TRMB], Garmin [GRMN] and Magellan are examples of commercial PNT receivers that work on GPS. None of the companies returned requests for comment. The Air Force also did not return a request for comment by press time.

GLONASS is noteworthy as Congress inserted a provision in the fiscal year 2014 National Defense Authorization Act (NDAA) preventing the president from authorizing or permitting the construction of a global navigation satellite system ground monitoring station directly on U.S. soil without the defense secretary and director of national intelligence (DNI) certifying it won’t be used to gather intelligence or improve a foreign weapons system.