Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - STRIKE3 (Standardisation of GNSS Threat reporting and Receiver testing through International Knowledge Exchange, Experimentation and Exploitation)

Teaser

GNSS is being used for an ever-expanding range of critical applications and European economies are now dependent on uninterrupted access to GNSS positioning, navigation and timing services. At the same time, GNSS vulnerabilities are being exposed and threats to denial of GNSS...

Summary

GNSS is being used for an ever-expanding range of critical applications and European economies are now dependent on uninterrupted access to GNSS positioning, navigation and timing services. At the same time, GNSS vulnerabilities are being exposed and threats to denial of GNSS service are increasing. To ensure GNSS is protected, the STRIKE3 initiative provides a response to monitor, detect, characterise and mitigate threats to GNSS services and applications. The project can be likened to the earliest developments in anti-virus software. Given societal dependence on GNSS, there is a growing need to persistently monitor the threat scene, to develop the “anti-virus” and to ensure GNSS as a robust and hardened system against any kind of attacks, be it intentional or unintentional.
To meet these objectives, the STRIKE3 project has developed draft standards for GNSS threat reporting and receiver testing. These standards have been developed through international collaboration, drawing on expertise from different domains. The threat reporting standards contain guidelines on how different types of equipment can be used to report on interference events using standard event criteria and message formats. The receiver test standards describe a common methodology, including equipment, test set-up and test metrics, for different stakeholders to test receivers against real-world interference threats.
To validate the draft standards, the STRIKE3 project has carried out long-term monitoring and receiver testing. The long-term monitoring activity installed a global network of 50 sites in 20 countries, and was used to create an extensive database of events. Such monitoring has enabled the STRIKE3 team to gain an in-depth understanding of the level of interference and types of signal that are commonly found in the real world. Receiver testing has also been conducted, following the proposed draft standards, on a selection of different receivers, using threat signatures commonly detected by the monitoring network. This has demonstrated the value of the test standards, and provided some interesting results on receivers’ resilience to interference threats.

Work performed

The STRIKE3 project ran for 3 years from February 2016. The main activities included a state-of-the-art review, development of standards for threat reporting and for receiver testing against threats, and validation of the standards through long-term monitoring and testing of selected receivers.
The main objectives of the state-of-the-art review were the identification of potential stakeholders and their challenges, analysis of existing monitoring and testing programmes and initiatives, and the identification of existing standards. A thorough literature review was performed and a questionnaire circulated to stakeholders to gain feedback on standardized interference reporting and testing. The main findings have been published the RIN Journal of Navigation in a paper entitled “GNSS Threat Monitoring and Reporting: Past, Present, and a Proposed Future”.
The standards development work looked at two areas: threat reporting standards and test standards. The reporting standards focused on a standard message format, content and definitions to allow standardised reporting of interference events. The test standards activity has focused on methodologies for identifying and selecting threats for testing, as well as the approach to testing GNSS receivers’ resilience to such threats. These draft standards are freely available from the project website.
The reporting standards have been validated through long-term monitoring from a global network of monitoring sites. This validation demonstrated the improved compatibility of reports from different systems when using the reporting standards, and has also built up an extensive database of interference events and signatures, allowing in-depth analysis to help understand the scale and nature of GNSS interference in the real world. The monitoring shows a significant amount of interference affecting all sites, although there is a wide variation in the level of activity between different sites depending on the type of infrastructure and the local environment, with busy sites (e.g. city centres) suffering most from interference. Despite the very high numbers of detected events, the vast majority were low power and short duration and do not cause any impact on GPS tracking. We also see much more unintentional than intentional interference. However, there are still many hundreds that cause a complete loss of GPS positioning at the monitoring site. In terms of the signals themselves, the work has identified the types of signals that pose most threat, i.e. those that are most common in the real world.
The receiver testing activity has tested a range of receiver types (mass-market, professional, etc.) against interference signals identified from long-term monitoring. The tests show that receivers have some resilience to the threats, i.e. they can continue to track satellites and provide position for some level of interference. However, the level of resilience is dependent on several factors, including receiver type, interference signal type, and GNSS (i.e. GPS vs Galileo). As each type of receiver reacts differently to the interference, and depends on configuration settings, this demonstrates the importance for procurement authorities, application developers, etc. to test their receivers’ in the configuration that will be used for their application.
Activities related to long term monitoring and receiver testing, as well as demonstrations of the reporting and receiver testing, have been presented at two STRIKE3 workshops. In addition, several presentations have been given at various conferences and a public summary of the results (D6.2 and D8.2) are available from the STRIKE3 project website.

Final results

In terms of achievements, the state-of-the-art review has provided a comprehensive assessment of a wide range of reference material on GNSS interference, including causes of threats, existing systems and monitoring activities, mitigation techniques, and existing reporting and test standards. Such a comprehensive review provides an excellent reference source for other researchers.
The key progress is in the development and validation of the proposed threat reporting and testing standards. The proposed standards provide guidance on methodologies for standardising reporting of events and testing of equipment against threats, and these have been presented and discussed in several international fora, including ICAO and UN ICG. Going forward it is hoped these can provide a reference set of methodologies for different stakeholders who wish to implement their own reporting or testing regimes. As well as the development of the standards, the validation through long-term monitoring from such a large-scale deployment of monitoring equipment is a significant achievement beyond previous activities. The results from this monitoring and analysis provide documented evidence of the level and nature of real-world interference, and this can be used to guide relevant stakeholders on actions to take and measures to put in place to help ensure GNSS remains robust and reliable.

Website & more info

More info: http://www.gnss-strike3.eu.