ARTICLE: ACCURATE PNT SERVICES
PROTECTING GNSS
Constructive action is required globally if we are going to develop safe, secure infrastructures for providing highly accurate and precise PNT services that are relied on to keep our society operating. By Guy Buesnel
A
ccess to Global Navigation Satellite System (GNSS) has become a fundamental expectation and a mainstay of the modern world. While the low strength of GNSS signals received on Earth means that they are particularly vulnerable to RF interference, multipath and atmospheric events, the use of GNSS to obtain precise timing and positioning data has become ubiquitous. In many cases, systems have dependencies on GNSS data that are not readily understood or recognized. The impacts of GNSS denial or disruption on these systems are largely unknown or untested, so when a disruptive incident does occur, the consequences are at the very least unexpected and can cause complete failure of dependent systems. The COVID-19 pandemic has made the task to secure our GNSS signals even more urgent. The recent blockage of the Suez Canal by a large container ship demonstrates just how quickly our just-in-time supply chains can be severely affected by an event.
Increasing risks
During 2019 and 2020, there was a concerning rise in the number of GNSS jamming and spoofing incidents worldwide. Several of those incidents have had widespread impacts, including, for 52 | www.gwprime.geospatialworld.net | March-April 2021
example, the reported spoofing of commercial shipping in the Black Sea in which hundreds of ships were affected, as well as the recent report by Eurocontrol that over 3500 GPS outages were reported to them in 2020. Internal flights in the northeast of Norway lost GPS reception multiple times in 2017 and 2018. This was attributed to jamming from nearby Russia — either as part of a Russian military exercise, or as a deliberate attempt to disrupt the NATO exercise Trident Juncture. Russia, however, denied the allegations. Military jamming exercises in the United States are also having an increasing impact on commercial and private aviation – such that the Aircraft Owners and Pilots Association has appealed to the FAA to recognize military GPS jamming as a safety risk. These nation-states initiated jamming and spoofing incidents often have the unintended consequence of affecting significant numbers of commercial users who have the misfortune of being located in the range of the powerful equipment that is available to nation states.
Real impacts
In June 2019, iHLS reported that container ports in Haifa and Ashdod experienced loss
of GPS reception, attributed to the ongoing Syria conflict. GPS-guided autonomous cranes were unable to operate, meaning the ports had to revert to manual methods of loading and unloading cargo. This incident has echoes of the hourslong shutdown experienced by an unnamed port on the US East Coast in 2014, in which the source of the jamming was never identified, or at least not made public. In 2016, more than 20 ships off the Crimean Peninsula reported that their electronic chart displays were showing their location as being on land. This was widely attributed to Russian GPS spoofing equipment designed to protect President Putin from possible drone attacks. The theory gained credibility with a March 2019 report by the Center for Advanced Defense Studies which also notes similar incidents in the Black Sea’s Kerch Strait. On 23 September 2020, The US Department of Transportation’s Maritime Administration (MARAD) issued a new warning on GPS interference affecting commercial shipping, following reported instances in eastern and central Mediterranean Sea, the Persian Gulf and multiple Chinese ports.
