By Tom Gray, VP of Product and Marketing of FocalPoint
Core GNSS technology hasn’t changed much since the first GPS satellite was launched in 1977. Today, systems like Europe’s Galileo, Russia’s Glonass and China’s Beidou rely on the satellites orbiting the earth at 20,000 kilometres, which emit a radio signal containing a timecode and a description of the satellite’s exact position. By measuring the transmission time of the signal, GNSS receivers can determine their distance from the satellite. If the receiver can access signals of at least four satellites in its line of sight, it can determine its position in three dimensions. That’s how ships know where they’re heading, autonomous vehicles can recognise they need to take the next turning and your watch congratulates you on reaching a personal best. But, as passive receivers, GNSS chipsets can be easily deceived and misdirected simply by broadcasting fake satellite signals at them. Frighteningly, these spoofing attacks are happening more and more.
In June 2017, French oil tanker, the Atria, lost its GPS signal as it approached the Russian city of Novorossiysk. When the signal finally reappeared, the position it gave was forty kilometres inland. Other vessels nearby reported similar malfunctions in their navigation systems with a total of 20 other ships impossibly located inland, at Gelendzhik Airport.
Around the same time, Uber customers in Moscow taking short trips across the city were charged for thousand-mile journeys to distant airports. There was speculation that Vladimir Putin’s security team might be using a portable device to disrupt GPS signals to mask the Russian President’s whereabouts and protect him from possible drone attacks. But this wasn’t an isolated incident. Researchers used data from ships’ continuous broadcasts and realised the problem was larger than anyone could have guessed. According to a report released in March 2019, there were ten thousand spoofing incidents at sea between February 2016 and November 2018, with 1,300 vessels affected.
GNSS spoofing or GPS spoofing (if it applies to the American satellite positioning system) involves the broadcasting of fake GNSS data to make a device think it is in different location. Timecodes can also be affected, since many IoT systems rely on satellites broadcasting accurate time in the correct time zone. That’s why the clock on your mobile phone automatically updates. It’s just one of the vast array of services in our connected world that rely on true time— from ATMs to cell phone towers, stock exchanges and electrical grids. Adjusting what systems believe to be the ‘true time’ by broadcasting fake signals can potentially be catastrophic.
Unfortunately, the cost and complexity of spoofing is coming down rapidly. Malicious individuals, who can purchase cheap equipment online and download free code, can broadcast spoof signals, disrupting radio mast signals and interfering with emergency services. And pocket-sized GPS jammers are proliferating. A few years ago, so many truck drivers on the New Jersey Turnpike were using jammers to obstruct their employers’ tracking systems that spill over interference disrupted the GPS landing system at Newark Liberty International Airport.
FocalPoint Positioning, a UK business set up by Dr Ramsey Faragher, part of the original design team for the ExoMars Martian Rover’s “Seeker” visual navigation system, has been working on an accurate, cost-effective solution.
Their Supercorrelation technology is a software upgrade to the GNSS chip which enables it to recognise and reject fake signals, based on determining the angle of arrival of the signal. This patented innovation works at a chipset level, using sensor fusion, machine learning and signal processing. When installed on a GPS receiver it can precisely determine where satellite signals are coming from, enabling the chip to ignore reflected and non-line-of-sight signals from positioning. This both protects the device from spoofing and enables 10x improvements in the accuracy and integrity of GPS. Supercorrelation enables chips to determine spoofer signals from true signals – discarding the signal, and thus securing the device against malicious interference.
These capabilities are currently only available in military grade technology costing tens of thousands of dollars. However, FocalPoint’s technology is designed to be installed at the chipset level on the GPS receiver – making it available to consumers and industry. Both the Royal Institute of Navigation and the US-based Institute of Navigation recently awarded prizes to Supercorrelation in recognition of its ground-breaking potential and FocalPoint is working with leading chipset companies to bring it to market.
Any IoT enabled device is only as good as the information it receives. Spoofers recognise this and are using GPS vulnerability to attack. Anti-spoofing solutions need to work across industries, across IoT devices and across geographies, to address this issue. Only then will we have confidence in the many thousands of ways we want to use GNSS / GPS technology to improve life on earth.