Soon: Jamming-Resistant GPS Signal 

Soon: Jamming-Resistant GPS Signal 

photo illus. satellite by Pixabay

This post is also available in: heעברית (Hebrew)

The U.S. Space Force has completed upgrades to the Global Position System’s ground segment that will allow it to partially use a new military GPS signal known as M-code. While the new anti-spoofing, anti-jamming, encrypted M-code signal has been available on many GPS satellites for years, the military has not had the corresponding ground and user equipment to access and leverage it.

A fourth GPS III satellite will be launched next month and final upgrades will be completed to the Air Force’s OCS ground control stations. Once 24 GPS III satellites are on orbit, the encrypted M-Code for military users will be available world wide.

Development of GPS user equipment that can utilize the M-Code signal has lagged behind the fielding of GPS M-code satellites for more than a decade, due to prolonged development challenges. 

The fourth Global Positioning System III satellite, Space Vehicle-4 (SV-4), was delivered to Cape Canaveral Air Force Station on July 14, where it will undergo pre-launch preparations. 

The highly encrypted M-Code to protect GPS signals from jamming and spoofing currently is enabled on 22 GPS satellites of various generations; 24 are needed to bring the M-Code to full operational capability.

The upgrade allows the M-Code to be used not just by GPS III, but by all older GPS satellites that are M-Code capable (GPS IIR-M and GPS IIF satellites.) It also allows M-Code functioning to be monitored by ground controllers, as well as supporting testing and fielding of user equipment. 

OCS is Lockheed Martin’s stop-gap GPS control system built as a bridge to Raytheon’s long-troubled and much delayed Next Generation Operational Control Segment (OCX), which was originally designed specifically to handle the M-Code. 

Once Operational Acceptance is granted, upcoming Military Ground User Equipment (MGUE) will be able to leverage the M-Code signal-in-space to provide more secure position, navigation and timing (PNT) to warfighters, according to