Within 1 year of the date of this order (Feb 12, 2020), the Secretary of Homeland Security, in coordination with the heads of SSAs, shall develop a plan to test the vulnerabilities of critical infrastructure systems, networks, and assets in the event of disruption and manipulation of PNT services. The results of the tests carried out under that plan shall be used to inform updates to the PNT profiles identified in subsection (a) of this section.
(a) “PNT services” means any system, network, or capability that provides a reference to calculate or augment the calculation of longitude, latitude, altitude, or transmission of time or frequency data, or any combination thereof.
https://www.whitehouse.gov/presidential-actions/executive-order-strengthening-national-resilience-responsible-use-positioning-navigation-timing-services/