SSC’s GPS Certifications Branch Keeps GPS Secured, Robust, and Accurate

  • Published
  • By Lt. Col. Patrick Spencer, SSC
With so many users worldwide – both civilian and military - depending on the accurate positioning, navigation, and timing (PNT) information provided by the Global Positioning System (GPS), it’s not surprising that Space Systems Command has a specialized branch responsible for certifying its accuracy.
The GPS Certification Branch is a specialized team within SSC that is responsible for certifying the hardware, software, and firmware used in GPS systems.
“Since the early seventies, GPS has been available to the world as a free-for-use service,” said William Chang, team 3, lead of SSC’s Functional Security Engineering Team (FSET), and Information Assurance Working Group (IAWG) member. “Over that time, the signals have improved in accuracy to the point where time can be configured to within a millionth of a second, velocity within a fraction of a mile, and location to within 30 centimeters (12 inches.)”
The certification process conducted by SSC’s GPS Certification Branch involves the evaluation of design and testing for various components of GPS systems. This includes user equipment - the devices used by individuals or organizations to receive GPS signals and determine their precise location.
The GPS Certification Branch works closely with GPS manufacturers, U.S. Department of Defense agencies, and other stakeholders to establish and maintain certification standards. Collaboration with industry experts, research institutions, and other certification bodies is also a key aspect of the branch's work to stay informed about technological advancements and ensure the certification process remains up to date with the latest developments.
“Driven by new and innovative uses for the GPS signal and revolutions from both the hardware and software industries, we need to not only keep up with the latest applications and technologies but also look into trends of future evolution to assure everything that works today can also be transitioned to future smoothly,” said Peter Youssef, SSC’s FSET team 1 lead and Anti-Tamper Working Group (ATWG) member.
The certification process also includes space segments, which are the satellites that transmit the GPS signals, monitoring stations, which track and monitor the performance of the GPS satellites, and the terrestrial modules, which provide end user secured and accurate signals.
“Making sure the space segments are working properly can be tricky,” said Kevin Kirkham, SSC FSET team 2 lead, and Cryptography Working Group (CWG) member. “As yet, on-orbit servicing isn’t possible. Fortunately, we have a complete constellation of 31 operational GPS satellites as of today, enough to provide accurate information, with a few we can sub in if one satellite malfunctions or unexpectedly reaches the end of its useful life.”

New GPS satellites are launched periodically – the latest, GPS III, Space Vehicle 6 was launched in January of 2023 – as older satellites reach the end of their useful life. And with each new iteration, new technology is added to make the system more robust, accurate, and resilient, Kirkham said.
Certification of hardware, software, and firmware is crucial to ensure that GPS systems meet the stringent standards set by the DoD. This certification ensures that the GPS systems used by the military and other DoD agencies are reliable, accurate, and secure. It also ensures that these systems are interoperable and compatible with other military equipment and communication networks.
Four global systems are currently operational: the United States' GPS, Russia's Global Navigation Satellite System (GLONASS), China's BeiDou Navigation Satellite System, and the European Union's Galileo. Among these systems, GPS is the most accurate navigation system in the world and remains the Gold Standard for global space-based positioning, navigation and timing, said Laurie Chin, branch outreach coordinator.
The assessment process conducted by the GPS Certification Branch involves thorough testing and analysis of the design, performance, and security of the GPS components. This includes assessing the hardware's ability to receive and process GPS signals accurately, the software's ability to interpret and utilize the GPS data effectively, and the firmware's ability to maintain system integrity and security.
GPS security assurance is a daunting effort to support critical mission elements at the infrastructure level of the DoD’s Joint All-Domain Command and Control (JADC2) framework. The space domain is no longer a benign environment, and adversaries can and will use space as a low-cost way to gain an asymmetric advantage during confrontation. The mission of the branch is to assure the GPS security functions from the developers do protect critical information and defend any types of physical or virtual threats so the U.S. and its allies can use the PTN information the way they need to, both militarily and commercially, to meet national interests.
By certifying the hardware, software, and firmware used in GPS systems, the GPS Certification Branch plays a vital role in ensuring the functionality, reliability, and security of GPS technology within the DoD. This certification enables the DoD to effectively utilize GPS systems for a wide range of military operations, including navigation, reconnaissance, targeting, and logistics.
To learn more about the critical role of SSC’s GPS Certification Branch to our nation’s reliance on GPS, check out this video.