Resilience Through Responsible Use of PNT

This page provides information and resources for improving positioning, navigation, and timing (PNT) resilience, especially in critical infrastructure.

As stated in the U.S. Space-Based PNT Policy: "The widespread and growing dependence on GPS by military, civil, and commercial applications, systems, and infrastructure make the performance of many of these systems inherently vulnerable if disruption or manipulation of GPS signals were to occur. GPS users must plan for potential signal loss and take reasonable steps to verify or authenticate the integrity of the received GPS data and ranging signal, especially in applications where even small degradations can result in loss of life."

Training Course

January 2025

DHS and CISA present The Federal Positioning, Navigation, and Timing (PNT) Services Acquisitions Guidance (V1.0) Training Course. CISA, in cooperation with the Homeland Security Acquisitions Institute, the Federal Acquisitions Institute (FAI), and Defense Acquisition University (DAU), developed this resource as a supplement to the Federal PNT Services Acquisitions Guidance (V1.0). This effort also supports DHS’s requirement under Presidential Executive Order 13905, Strengthening National Resilience Through Responsible Use of Positioning, Navigation, and Timing Services. The primary aim is practical application in developing PNT contractual language for users of the guidance, with the risk management goal of establishing robust and secure PNT services.

This course serves as a companion resource to the PNT acquisitions guidance (V1.0), walking users through each section of the guidance and providing video-guided subject matter expertise, context, explanations, and examples of key PNT principles. The training tool also includes critical learning checkpoints for content reinforcement and user retention.

If you are interested in taking The Federal PNT Services Acquisitions Guidance (V1.0) Training Course (FAC-200), you must have an FAI or DAU account. All contractors must have a federal sponsor to obtain a FAI or DAU account. If you have an existing FAI or DAU account, simply login with your existing credentials and search for “FAC-200”.

To access FAC-200 at FAI, go to FAI main home page. Once you are logged into FAI’s learning management system/catalog Cornerstone OnDemand (CSOD), here is the link to the FAC-200 course.

To access FAC-200 at DAU, if you already have a DAU login, click here and enter those credentials. If you need to create an account, click here.

Guidance for Critical Infrastructure Owners & Operators

Presentations & Information Sheets

• Jun 2021: Understanding vulnerabilities of positioning, navigation, and timing (PDF)
• May 2021: NIST-DHS presentation at RSA Conference 2021 USA
• Jan 2020: Responsible use of PNT in the financial services sector
• Mar 2019: Time — The Invisible Utility
  • Corporate level info sheet (PDF)
  • Technical level info sheet (PDF)
• Dec 2017: Responsible use of GPS for critical infrastructure

Best Practices

• Feb 2025: Best Practices for Resilient PNT Supporting Critical Infrastructure
• Jul 2020: Time guidance for network operators, CIOs, & CISOs (CISA.gov)
• Jan 2017: Improving the operation and development of GPS equipment used by critical infrastructure (PDF, us-cert.gov)
• Jan 2015: Best practices for improved robustness of time and frequency sources in fixed locations (PDF, CISA.gov)

Implementation Frameworks

• Jun 2022: Resilient PNT reference architecture (DHS.gov)
  • News release (DHS.gov)
• May 2022: Resilient PNT conformance framework, v2.0 (DHS.gov)
  • Jun 2021: DHS transitions framework to IEEE for standards development (DHS.gov)
• Feb 2021: Free resources to protect critical infrastructure from GPS spoofing (DHS.gov)
  • PNT integrity library (github.com)
  • Epsilon algorithm suite (github.com)
• Feb 2021: Foundational PNT profile: Applying the cybersecurity framework for the responsible use of PNT services (NIST.gov)
  • News release (NIST.gov)
  • Quick guide (PDF)
  • RFI & webinars (NIST.gov)

GPS Week Number Rollover

Federal Activities

Demonstration & Testing

• Mar 2020: GPS backup/complementary PNT demonstration (transportation.gov)
  • Jan 2021: DOT report to Congress (transportation.gov)
• Apr 2020: GPS spoofing test event (DHS.gov)

Planning

• Nov 2021: A resilient architecture for the realization and distribution of UTC to critical infrastructure systems in the United States (12.7 MB PDF)
  • News release (NIST.gov)
• Nov 2021: An evaluation of dependencies of critical infrastructure timing systems on GPS (5.4 MB PDF)
• Aug 2021: National R&D plan for PNT resilience (700 KB PDF)
• Jan 2021: DOT report to Congress on NTRSA (transportation.gov)

Outreach

• Aug 2022: Complementary PNT industry roundtable (transportation.gov)
• Dec 2020: DOT workshop on maritime GPS jamming & spoofing (transportation.gov)

Acquisitions Guidance

• Apr 2024: The Federal PNT Services Acquisitions Guidance (V1.0) (CISA.gov)

National Policy

• Jan 2021: U.S. Space-Based PNT Policy (archives.gov)
• Dec 2020: National Space Policy
• Feb 2020: Executive Order on Strengthening National Resilience Through Responsible Use of PNT Services (federalregister.gov)
• Dec 2018: National Timing Resilience and Security Act (NTRSA)
• Additional legislation on backup and complementary PNT

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