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Articles

GPS Spoofing

Sub Title :

Issues Details : Vol 17 Issue 6 Jan – Feb 2024

Author : Gp Capt Anil Sharma

Page No. : 66

Category : Military Technology

: January 27, 2024

Modern navigation’s shift from stellar to satellite guidance is threatened by GPS spoofing, risking aviation safety and necessitating regulatory vigilance and robust countermeasures.

Ancient mariners used stars to navigate their way around the oceans in a very basic manner. And while the fundamental principle remains the same, GPS or Global Positioning System uses a sophisticated system of satellites. Over 30 navigation satellites are orbiting the Earth with a network of ground stations. A GPS receiver listens out for signals from the satellites, and once it calculates the distance from four or more satellites, it tells you exactly where you are with incredible precision!

Everyone wants to know where they are, so GPS has become ubiquitous. But then there are others who don’t want you to know where you are, and thus was born spoofing. GPS spoofing is when a false radio signal is transmitted to a receiver antenna to counteract and supersede a legitimate GPS satellite signal. It is a form of cyberattack carried out by hackers attempting to steer platforms, goods, or people off course. GPS spoofing can be used to create errors in air and marine navigation. Spoofing is a real threat to GNSS. Unlike jamming, which is intended to block GNSS signals, spoofers are altogether far more sinister. By replicating GNSS signals, a spoofer can fool a receiver into thinking that it’s elsewhere in either time or location. A cheap Software Defined Radios (SDR), combined with the availability of open-source code has made spoofing far more accessible to amateurs on a limited budget. Given our reliance on GNSS technology not only for positioning but also timing in various platforms such as aeroplanes, autonomous drones and machines and critical infrastructure, it’s not hard to imagine the potential havoc that a spoofing attack might cause.

Modern airliners rely heavily on Global Navigation Satellite Systems (GNSS). GNSS is a wider term that includes satellite navigation systems of various countries such as GPS of USA, GLONASS of Russia, Galileo of Europe and BeiDou of China   Any interference with satellite signals can lead to projecting a false air position, which in turn can have serious consequences impacting safety of the flight and its passengers.

With ongoing conflicts in Europe (The Ukraine war) and the Middle-East (Israel-Gaza conflict), the airspace in the vicinity seems to be full of spurious signals Some of the Indian Air Carriers which overfly these regions, namely Air India and Indigo have reported widespread navigational errors due to GPS spoofing. In addition to the conflict zones proximity, some of the other areas where GPS spoofing/jamming has been observed are Mediterranean and Black Sea, Baltic Sea the Arctic area and some of the airspace over Moscow and Minsk.

Recognising the problem early, Indian Aviation Regulator, Directorate General of Civil Aviation set up a committee headed by Director Airspace & Air Navigation Services Standards, Cdr Ravinder Singh Jamwal. Based on the Committee’s recommendations,  an initial advisory was issued to all pilots, airlines and ATC officials on how to deal with GNSS spoofing issues. Director General, DGCA, Vikram Dev Dutt aptly highlighted the problem while saying “ With increased reliance and dependency on GNSS, its interference including jamming and spoofing,  has become a real threat in airspace.” All aircraft operators and Air Navigation Service Providers were advised to formulate contingency procedures and to conduct safety risk assessments. 

A comprehensive Advisory Circular issued by DGCA details how spoofing/jamming of GNSS could result in loss or degradation of performance of various aircraft systems such as the positioning, navigation, timing or surveillance systems. “Ground-based surveillance and ATM/CNS systems can also be compromised,” says Cdr Jamwal, adding that “ a more serious  consequence is deviation of an aircraft from its planned flight path which may lead to separation minima infringement or airspace infringements. We have advised all aircraft operators and other aviation agencies to be vigilant about this problem and given them detailed action plans to ensure safe aviation operations.”

Safety remains paramount in all air operations. And for that, navigation systems such as GNSS must remain in robust health, free from interference/jamming. Inertial sensors can help to determine the actual position and caesium, or rubidium clocks can work as backup timing systems when GPS is down. Backup systems that do not rely on GPS are helpful in the event of an issue.

That the Aviation Regulator is keeping a watchful eye inspires confidence