Photo: Andrea Izzotti/

Blog Editor’s Note: The author is President of the RNT Foundation.

2021 Defense Act signals turning point for Congress and PNT


December 29, 2020  – By 

Senate poised to join House this week and override Trump’s veto

The U. S. Congress, especially the Armed Services Committees, have long been concerned about GPS and positioning, navigation, and timing (PNT) issues. Over the last two decades Congressional hearings, demands for reports, and investigations have dealt with acquisition, contingency plans for when space is not available, deliberate interference, and a host of other issues.

While these all evidenced Congress’ interest and concern, they were relatively passive measures.

The NDAA for 2021 seems to finalize Congress’ transition from an interested observer, mostly on the sidelines, to an active player in national PNT issues and policy.

This began to change in 2018 with passage of the National Timing Resilience and Security Act. It requires the Department of Transportation to establish a terrestrial timing system to backup GPS signals.

Then in 2019, Congress appropriated money for a GPS Backup Technology Demonstration. And the National Defense Authorization Act (NDAA) for 2020 required the Air Force to develop a prototype multi-GNSS receiver as part of its resiliency efforts.

The NDAA for 2021 seems to finalize Congress’ transition from an interested observer, mostly on the sidelines, to an active player in national PNT issues and policy.

Capitol Hill observers say this is the result of several things that have come to a head over the last year. Taken together, they have convinced many legislators that GPS is under threat and PNT issues are not being taken seriously enough by the executive branch. These include increased jamming and spoofing (especially by China and Russia), full implementation of China’s BeiDou system and its marketing to other nations as a superior alternative to GPS, the Federal Communications Commission’s (FCC) decision on Ligado Networks, and the Pentagon’s failure to respond to combatant commanders’ Joint Urgent Operational Needs Statements for non-GPS PNT.

Here are some of the provisions of the 2021 NDAA of interest to the PNT community.

Military Multi-GNSS Receiver Prototype

The 2018 NDAA required the Defense Department to incorporate Europe’s Galileo and Japan’s QZSS satellite navigation signals into military user equipment. The idea was to make it more resilient to disruption. Also required was an investigation into using non-allied signals.

Apparently not satisfied with progress on this project, Congress mandated a project to develop a prototype multi-GNSS receiver as part of the 2020 NDAA.

The 2021 NDAA seems to indicate the Congress is still not happy. It withholds 20% of the funding for the Office of the Secretary of the Air Force until such time as the department certifies the prototype project is underway and provides briefings to the Senate and House Armed Services Committees.

Resilient Survivable PNT

Language in the 2021 NDAA also seems to show Congress is impatient with the Pentagon’s lack of responsiveness to combatant commanders’ requests for non-GPS PNT systems.

Section 1611 of the Act is entitled “Resilient and Survivable Positioning, Navigation, and Timing Capabilities.” It requires development, integration, and deployment of these capabilities for combatant commanders within two years. This, it says, is “… consistent with the timescale applicable to joint urgent operational needs statements…”

The act says the new PNT capabilities shall “generate resilient and survivable alternative positioning, navigation, and timing signals” and “process resilient survivable data provided by signals of opportunity and on-board sensor systems.”

The act also reverses the Defense Department’s 2018 PNT Strategy’s plan for future systems to be classified and for military use only. It directs the department to work with the National Security Council, Departments of Transportation, Homeland Security and others “to enable civilian and commercial adoption of technologies and capabilities for resilient and survivable alternative positioning, navigation, and timing capabilities to complement the global positioning system.”

To help ensure prompt action on this, the act requires a report to Congress within six months and authorizes the department to reprogram funds from other areas to finance the effort.

Responding to FCC’s Decision on Ligado Networks

By far the most PNT-related text in the 2021 NDAA includes a host of measures responding to FCC Order 20-48 approving an application by Ligado Networks. An order which the executive branch is on record as strongly opposing saying it will degrade GPS service for many.

Senator Jim Inhofe, chair of the Senate Armed Services Committee, has regularly expressed outrage at the FCC’s decision and has called for its reversal.

Among its provisions the act:

  • Requires the Department of Defense to estimate and report to Congress the cost of damage to department systems as a result of the FCC order.
  • Prohibits using department funds to upgrade or modify military equipment to make it resilient to interference caused by broadcasts in the spectrum allocated (the FCC order requires this to be funded by Ligado)
  • Prohibits contracting with any entity using the frequency bands allocated to Ligado unless the Secretary of Defense certifies the use will not interfere with GPS services
  • Requires the Secretary of Defense to contract with the National Academies of Sciences, Engineering, and Medicine for an independent technical review of the FCC order.