Schematic of the GNSS interference detection and analysis system GIDAS. (Image: OHB Digital Solutions)
In September 2020, the first GIDAS monitoring stations were installed at the Czech airport in Brno.
GIDAS — GNSS Interference Detection and Analysis System — enables continuous 24/7 monitoring of the GNSS frequency bands within a defined region to automatically detect, classify and localize intentional interference from jamming and spoofing.
GIDAS can raise the alarm in real time, identify the type of interference, and then pinpoint the location of these dangerous portable devices causing the interference so the authorities can take immediate remedial action. It considerably improves safe and robust operation of GNSS receivers, terminals and applications.
GIDAS was developed by OHB Digital Solutions and Joanneum University of Applied Sciences through ESA’s Navigation Innovation and Support Programme (NAVISP).
The system works autonomously and is designed to be easily deployed. It is scalable and flexible; it can be used as a standalone monitoring station or upgraded to a network of stations.
Recent GNSS interference attacks include:
shutdown of navigation equipment at Newark airport
GNSS attacks of North Korea against South Korea
117 incidents within one day at Kaohsiung airport in Taiwan
a U.S. military drone forced to land
a 65-meter yacht drifting off course during field trials
failure of emergency pagers, traffic management systems and ATMs in San Diego caused by U.S. Navy jamming.
“In recent years, GNSS applications have increasingly become the target of intentional interference attacks, since GNSS is widely used in safety and value-critical applications,” said Andreas Lesch, CEO of OHB Digital Solutions. “GIDAS detects, classifies and localizes GNSS interference signals and thus reduces the already existing threat of receiving worse accuracies or even denial of service.”
The GIDAS system user interface helps to pinpoint interference. (Image: OHB Digital Solutions)
GIDAS monitors the GNSS L1/E1 frequency band and reliably detects and classifies intentional and unintentional interference sources using sophisticated algorithms. GIDAS consists of a high performance data processing unit including antenna and RF front-end, and a sophisticated software solution.
GIDAS is able not only to monitor GNSS-based position, velocity and time solutions, it monitors the received signal and baseband processing.
The system is composed of the following software modules:
Software-defined GNSS radio
Position, baseband and C/N0 monitoring
Jammer and spoofing parameter estimation
Localization capabilities through synchronization of several GIDAS systems
Graphical user interface
Initial GIDAS reports show an average of seven GNSS interference events per day. GIDAS was able to successfully classify the signal type in 96% of jamming cases that have occurred.
A new monitoring system developed through an ESA-backed project works like a bodyguard for satellite navigation in use at strategic or safety-critical sites. Known as GIDAS, the scalable system immediately detects, identifies and pinpoints satnav interference sources in its vicinity.
It is estimated that there are currently the same number of satnav receivers on Earth as there are people. Positioning, navigation and timing signals from space-based constellations such as Galileo and GPS form an invisible, essential infrastructure, underpinning numerous modern aspects of modern life: communications, power and transportation.
Satellite navigation helps guide a growing number of aircraft, boats, trains and autonomous vehicles. Meanwhile satnav-based time stamps authentic multi-billion euro financial transactions, and coordinate the synchronised running of power grids. Satellite navigation is always on, available everywhere on Earth, so it is easy to take its availability for granted. But as crucial as these signals from space are, they are also vulnerable to ground-based interference.
“It’s simply a matter of output power,” said Andreas Lesch of Austria-based OHB Digital Solutions. “A navigation signal on the ground is equivalent to the light from a 60-watt lamp aboard a satellite, some 23,222 km away in space in the case of Galileo. So these faint signals can be jammed by more powerful local radio signals, either accidentally or deliberately, or even misleading fake navigation signals, known as spoofing.”
“Our new GNSS Interference Detection and Analysis System, GIDAS, is designed to safeguard critical infrastructure against jamming or spoofing, by performing continuous monitoring of key signal bands. By doing so, GIDAS can raise the alarm in real time, identify the type of interference then pinpoint the location of these dangerous portable devices causing the interference so the authorities can take immediate remedial action.”
GIDAS can provide interference detection and directionality with a single reporting station, although a minimum of three stations are required for pinpointing interference sources, linked to an overall monitoring center. Monitoring centers can also be connected together, making the GIDAS system easily scalable, from safeguarding an individual harbour, airport or system critical site up to an entire city or region.
GIDAS can provide interference detection and directionality with a single reporting station, although a minimum of three stations are required for pinpointing interference sources, linked to an overall monitoring center. (Photo: ESA)
“People are only now catching up to the seriousness of this problem,” adds Andreas. “Surveys of the highest-density parts of Europe surveys report around three to four jammers hourly.
“These small devices are technically illegal but are easily available online for a few hundred euros or less, often marketed as personal privacy devices. Jammers are sold as having a range of only a few metres, but can turn out to have a practical range of dozens of metres or more — leading to unintentionally widespread interference, like the famous jammer-equipped U.S. truck driver who shut down Newark Airport navigation systems whenever he drove past.
“Spoofing is more serious still, with a strong criminal element, where false satellite navigation signals replace real ones, to mislead receivers about their position, employed in the past to down put drones or divert boats.
“Working in this field for eight to nine years, we have seen a strong growth in interference, even as GNSS becomes ever more crucial. With our passion for GNSS and signal processing, we decided to something practical to combat this development, delivering rapid detection, classification and localisation of interference to our customers.”
GIDAS was developed by OHB Digital Solutions and Joanneum University through ESA’s Navigation Innovation and Support Programme (NAVISP), working with European industry and academia to develop innovative navigation technology.
“The company initiated the project through NAVISP’s second element, focused on strengthening European competitiveness in the navigation arena, proceeding on a co-funded basis,” said engineer Thomas Burger, overseeing GIDAS project for ESA. “The plan was to enable a commercially attractive business to get started, and I’m happy to say we made it.”
“Considering the budget, the project had a wide scope, including the development of a multi-constellation GNSS receiver with all processing stages, an extended digital front end for jamming and spoofing detection, processing blocks transferred to a parallel processor based on a customised fully programmable gate array.
“And that was only one ingredient of the overall GIDAS system, also including the actual interference detection machinery, the interference locating subsystem, and all the communication, database, and graphical user interface elements needed to create a distributed, human-usable system — which is able to go on working autonomously, only asking for human involvement when events are detected.”
Now that its two-year NAVISP project has concluded, GIDAS is now being rolled out to several Europe-based governmental and private sector customers.
