120 - Resilient PNT Critical National Infrastructure validation test bench

Satellite navigation has widespread usage and very satisfactory performance for most of the professional and consumer applications. However, for certain uses, there is increasing awareness of satellite navigation weaknesses and limitations.
In his keynote address at the IEEE/ION PLANS 2025 the “Father of GPS” Dr. Brad Parkinson, who proposed the “Protect, Toughen, Augment” (PTA) framework for PNT applicable to Governments, Industry and Academia, attempted to push forward the implementation of the resilience in PNT. The message was that it is important to recognize the weaknesses and limitations, and design layered responses to overcome them and provide PNT assurance. In his intervention, he tries to define what “assured PNT” is, as a function of the performance the product or service has to deliver as a minimum. He defines therefore 5 Categories of applications: Common, Basic, Advanced, Survey and Time.

In 2020, the US Department of Homeland Security defined four levels of resilience as part of the US Resilient Positioning, Navigation, Timing Conformance Framework, that is now transitioning to the IEEE P1952 Standard. The ascending order is aligned with the increasing level of resilience, but not all applications require the maximum level 4.

In several ESA Member States initiatives have emerged on the subject, with, among the others, studies and technology developments implemented under NAVISP, which also helped to frame the problem (from the early EL3-014 “GNSS Event Notification Service” to the recent EL3-037 “Supporting the UK public sector in PNT Awareness, Research and
Knowledge” and EL3-031 “National GNSS Knowledge Center”).

As a notable example, the Royal Institute of Navigation (RIN) in UK realized a “Resilient PNT Resources portal” on the Internet, to support Critical National Infrastructure (CNI) operators and suppliers to understand why resilience to intentional and unintentional, natural and man-made threats and, in general, PNT disruptions, is important for their mission. According to RIN, the key principles for Resilient PNT are: 1) “Prepare for PNT disruptions”; 2) “”Act when PNT disruptions occur”; and 3) "Recover from PNT disruptions”. Fundamental aspects in the application of these key principles are, respectively, to “Test system responses to understand effects of PNT disruptions on system behaviour”, to “Detect disruption events as soon as possible after they occur” and to “Share lessons learned when reporting incidents and their associated impacts”.

The objective of the proposed activity is to make available In the ESA Member States industries the most important technologies to ensure that CNI Operators and suppliers can comply with the requirements of the Prepare/Act/Recover key principles for Resilient PNT. In the event that the activity has to use or generate sensitive information, it will be handled in compliance with the national law of the Contractor and with the provisions for Limited Distribution information (Protection Level 2) at ESA level.

The tasks to be performed shall include:

•  Survey common and typical CNIs and define use cases of PNT technology integrated into them and its related potential disruptions. For example, GNSSs is used almost everywhere to achieve time synchronisation to UTC, standalone (often with an external clock to provide a holdover mechanism during disruptions) or in combination with network protocols like NTP/PTP. For several CNIs (for example tracking of dangerous goods), location of assets will also be based on GNSS;
•  Design and develop a validation test bench, with the capability to inject to representative equipment, sub-systems, and systems under test, as applicable, signals impairment, also collected in the field with RF signal samplers, with different levels of disruption (for example, GNSS RF jamming and spoofing), and to measure the impact over nominal performance;
•  Develop a comprehensive, well-labelled training database for GNSS interference detection using Machine Learning (ML), to support the benchmarking of ML algorithms;
•  Perform independent FTA and FMECA analysis of existing products and services, in collaboration with PNT products and services suppliers, to suggest products and services improvements as regards the mechanisms and the latency for the detection of disruption events;
•  Design a searchable database of Lessons Learned, including all the technical details regarding the characteristics of the events and their impact on various classes of PNT equipment, necessary to perform searches and correlations with newly observed events, and populate it with representative records.

The main outputs of the activity will consist of:

•  Validation test bench to evaluate the response to PNT disruption events, with user manual;
•  Database of Lessons Learned populated with representative records, with user manual;
•  Final report incorporating use cases descriptions, test bench design and verification, description of disruption events detection mechanisms and Lesson Learned database description.

It is noted that no Participating State expressed their opt-out for this activity (EL1-120).