GPS spoofing in Korea highlights a growing threat to commercial aviation

A fresh spate of electronic warfare on the Korean border has highlighted the risks to civil aviation of GPS spoofing.

On the 9th November, Reuters reported that North Korea was “staging GPS interference” in the border region, affecting private aircraft and shipping in the West Sea.

The German IT newswire Heise Online identified the disruption more specifically as a GPS spoofing attack, involving “falsified navigation signals”. It noted that similar activity in June of this year disrupted commercial flights out of Seoul’s Incheon International Airport, close to the North Korean border. Al-Jazeera reported that around 500 flights were affected at that time.

GPS spoofing is a growing risk to civil aviation

This is just the latest reported example of a type of navigation warfare (NAVWAR) that is becoming rapidly more prevalent in geopolitically-contested zones around the world. As reliance on global navigation satellite systems (GNSS) grows, nation states are increasingly using GPS spoofing to disrupt the military operations and economic activity of adversaries.

Spoofing works by broadcasting fake or pre-recorded GPS signals, often at a higher strength than that of the very weak signals arriving from GPS satellites in space. Receivers that have not been hardened against spoofing can lock on to these fake signals rather than the real ones, causing them to calculate an inaccurate position.

Usually, the spoofing attack has a specific target in mind—often it’s to prevent drones from flying over particular areas. Many commercial drones have built-in geofencing controls that instruct them to land or return home when they are approaching a geofenced area such as an airport. If the spoofed signals navigate to the co-ordinates of an airport, it can force drones to land or leave the area.

Spoofing affects around 1,500 commercial flights per day

The problem is that spoofing using an upward-pointing broadcast antenna is a wide-area attack, so other unprotected receivers in the area may also lock on to the fake signals and start outputting erroneous positions. The GPS receivers used in most commercial aircraft are particularly vulnerable, since they typically receive signals from just one satellite system (GPS) and on just one frequency (L1), making the signals they rely on quite easy to replicate.

This leaves commercial aviation at heightened risk from spoofing, and that risk is rapidly turning into real danger. A report published in September by OPSGROUP showed that around 1,500 flights per day are affected by spoofing, with GPS World reporting effects including “sudden clock resets, false terrain warnings and unexpected flight path deviations.”

While flight crew are usually able to find workarounds when systems are affected, the ever-present threat of spoofing is damaging to morale. OPSGROUP found that 70% of crew have “very high” or “extreme” concerns about the impact of spoofing on flight safety. It also identified a risk that safety measures, like alerts from Ground Proximity Warning Systems (GPWS), may be ignored if they result too often from inaccurate GPS outputs caused by spoofed signals.

How to protect civil aviation against the threat of GPS spoofing

With spoofing continuously increasing in prevalence worldwide, the civil aviation industry is rightly taking steps to mitigate its impact. Spirent has developed a suite of content, products and services to help the industry evaluate the risk and take appropriate action.

Drawn from our 35+ years at the forefront of position, navigation and timing (PNT) test and measurement, including work with leading aerospace and defense organisations, Spirent can offer the following assistance with spoofing threat mitigation:

• eBook: Protecting Commercial Aircraft Against GPS Spoofing Threats. This complimentary eBook looks at the risks to airlines and aircraft from GPS spoofing, and sets out a recommended mitigation roadmap with actions to take in the immediate, medium and longer-term.

• Spoofing Detection and Alerting Service (SDAS): A real-time service that integrates with Electronic Flight Bags, apps, and computer tablets already used on the flight deck, to ensure minimum disruption and immediate real-time situational awareness. Similar to windshear and turbulence warning systems (WTWS), the SDAS notifies crews of spoofing along their active flight path, providing information that includes duration and impacts of the specific attacks. It can also warn other pilots and ATC of areas of inaccurate aircraft position to increase safety and where possible avoid interference.

• Spoofing scenario packs: Aircraft GPS receivers, and the systems that depend on them, should be lab-tested to understand how they respond to spoofing interference, so that appropriate mitigations can be put in place. Spoofing attacks vary in nature and can be very sophisticated, so test scenarios should reproduce a wide range of attack types as realistically as possible. Spirent offers packaged and bespoke spoofing scenario packs for use with Spirent PNT simulators.

• Receiver and antenna test equipment: For manufacturers and integrators of GPS receivers for use in civil aviation, Spirent offers industry-leading simulation equipment for both conducted testing of receivers and over-the-air testing that incorporates antenna systems. Our expert consultants are available to assist with any aspect of GPS vulnerabilities testing for receivers, antennas, avionics and aviation systems that rely on GPS data.

Talk to us about protecting against GPS spoofing

The recent GPS interference in Korea is just one of many such incidents worldwide affecting commercial aviation. If you’d like to understand more about the risks to aircraft systems, or if you’d like to talk to an expert about assessing your risk exposure, please do get in touch.