by Mélissa Capizzi

GNSS outages: Safeguarding global navigation systems in aviation

The numerous recent cases of GPS spoofing have raised serious questions about the vulnerability of GPS systems in aviation.

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On this page Safety

Global Positioning System (GPS) technology, a cornerstone of Global Navigation Satellite Systems (GNSS), has become an integral part of our daily lives, revolutionising navigation, asset tracking, and location pinpointing with remarkable accuracy. Despite its transformative impact, the vulnerability of GPS poses significant risks and challenges, particularly in the realm of aviation. For this reason, it is worthwhile to explore the escalating issue of GNSS outages, with a specific focus on GPS spoofing and jamming, examining its causes, consequences, and the collaborative efforts required to address this critical concern.

GNSS outages severely impact  aviation safety

GNSS outages involve the loss of satellite signals, disrupting navigation systems and posing risks to aviation safety. The Airbus Flight Data Monitoring has reported a substantial increase in GNSS outages, with 49,605 incidents in 2022 compared to 10,843 in the previous year. This surge in disruptions emphasises the pressing need for comprehensive solutions to safeguard GNSS systems.

Stakeholders and legal considerations

The impact of GNSS outages extends to a myriad of stakeholders, including Air Navigation Service Providers, operators, flight crews, and equipment and aircraft manufacturers. Legal considerations, such as the allowance of GNSS outages for research and security testing in certain regions, add complexity to the issue. It is crucial to intervene and address the expanding severity of GNSS outages to prevent potential safety issues, particularly in conflict zones and specific geographical regions.

What are the main causes of GNSS outages

Three primary causes contribute to GNSS outages: interference, jamming, and spoofing. Jamming, intentional radio frequency interference, renders the GNSS system ineffective for users in the affected area. Spoofing, a more sophisticated technique, involves generating false GPS signals to deceive receivers, leading to incorrect location information.

The aviation industry has been slow to grapple with the challenges of GPS spoofing, leaving flight crews to find ways of detecting and mitigating these events. Distinguishing between jamming and spoofing, along with the lack of specific flight crew alerts for interference, complicates the detection process. Aircraft integration variations further contribute to the difficulty in analysing the impact and determining appropriate procedures.

Recommendations and safety measures                                                                                

Recommendations and safety measures span multiple levels, including air operators, CAAs, Air Navigation Service Providers and EU-wide initiatives. EBAA is calling upon EASA and the OEMs to give clear guidance and procedures for operators on how to recognise and safely deal with GPS spoofing. The operators should then consider training their crews, by adding spoofing scenarios to their training.

Furthermore, EBAA urges ANSPs operating in the impacted regions to facilitate thorough communication by sharing relevant information into NOTAMs. Additionally, in cases where deemed necessary, it advocates for ATCOs to proactively engage in informing flight crews.

Collaborative approach to find adequate countermeasures

In conclusion, the rising concern of GNSS outages, particularly GPS spoofing, demands a harmonised, collaborative, and integrated approach to monitoring and safeguarding navigation systems. Civil-military coordination, enhanced cooperation among states and stakeholders, and the implementation of countermeasures are essential steps in mitigating the impact of GNSS outages.

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