“GPS is so important in our everyday lives. If it were to go away for a significant amount of time, I am sure lives would be lost.” Credit: Adobe Stock

Aircraft, cars, trucks, trains and ships rely on GPS for location data, while GPS timing signals underpin cellular communications and financial transactions.

A 2019 report sponsored by the National Institute of Standards and Technology estimated the loss of GPS would cost the U.S. economy $1 billion a day, or $1.5 billion if the technology failed in the April-May planting season for farmers. Two years later, the costs could be even higher with the sharp rise in consumer solutions and location-based rideshare and delivery services.

“Positioning, navigation and timing signals are important to so many stakeholders and for so many different applications that a disruption in these signals would likely be more economically significant today,” Alan O’Connor, senior economist and director of innovation economics at RTI International, the nonprofit research institute that prepared the 2019 report, said by email.

GPS and its GNSS (Global Navigation Satellite System) counterparts — Europe’s Galileo, Russia’s GLONASS and China’s Beidou — play a vital role in myriad economic activities. India’s NavIC and Japan’s QZSS are similarly important in their respective regions.

GPS is the oldest and mostly widely used PNT system. Many infrastructure networks still rely on GPS-only legacy receivers. Multi-constellation receivers are becoming a norm to provide for GNSS continuity and accuracy. Since these receivers pick up signals from any available GNSS satellite, irrespective of the constellation, they should theoretically provide service continuity in the event of GPS loss. However, because they rely primarily on GPS, it’s not clear how they would behave if GPS were lost for hours.

“GPS is so important in our everyday lives. If it were to go away for a significant amount of time, I am sure lives would be lost,” Dana Goward, president of the nonprofit Resilient Navigation & Timing Foundation, said by email.

Since GPS established a constellation to provide worldwide positioning, navigation and timing information in 1993, Russia, China and Europe have followed suit. The European Commission and the European Space Agency are on track to complete the Galileo constellation by the end of 2022. Credit: SpaceNews/Penn State

To date, GNSS outages have lasted less than one day, but a longer breakdown is possible. Galileo suffered a six-hour systemwide failure on Dec. 14, 2020, and a weeklong outage in July 2019. GLONASS failed in 2014 when its satellites broadcast corrupt information for 11 hours.

Outages of individual GNSS satellites are common and the systems are often subjected to localized jamming and spoofing. In 2016, GPS-dependent timing equipment showed errors after an older satellite was retired. The 13-microsecond discrepancy affected police and emergency communications equipment in parts of North America for hours and caused power grid anomalies.

One reason GNSS failures are farreaching is the timing element. GNSS satellites rely on atomic clocks for signal synchronization, which allows users to determine the time with nanosecond accuracy. As a result, banks rely on GPS to report the precise timing of financial transactions and cell towers use it to synchronize network nodes.

“The U.K. is critically dependent on GNSS. These services are integral to the U.K.’s safety, security and prosperity, overseas territories and wider global interests,” Ian Annett, UK Space Agency deputy CEO, said by email.

THE SAME IS TRUE FOR THE UNITED STATES.

If GPS were to fail, “it’s impossible to predict the exact sequence of events,” Goward said. “Transportation and first responders will suffer immediately. There could be more accidents. Cellphones and internet will begin to degrade, but it’s hard to say how much and how quickly.”

The COVID-19 pandemic made the U.S. economy more reliant than ever on telecommunications infrastructure.

“There is broader recognition of the role infrastructure plays in our economy, though many people are unaware of the connections between GPS, robust positioning, navigation and timing signals, and the apps and tools we use every day,” O’Connor said.

ECONOMIC IMPACT OF DISRUPTION

A 2017 study commissioned by Innovate UK, the UK Space Agency and the Royal Institute of Navigation estimated a five-day GNSS disruption would have an economic impact of 5.2 billion pounds ($7.2 billion), with road, maritime and emergency service impacts accounting for 88 percent of the cost. Goward said the cost of disruption would be far higher in 2021 since location data has become pervasive. The UK Space Agency has commissioned an updated study to determine the potential economic impact.

The past decade has seen a sharp rise in the value of GNSS, which largely coincides with the rise in smartphones, smart devices and internet penetration, enabling a spurt in consumer solutions.

“Satellite navigation systems are also important to unlocking future technologies such as driverless cars, smart cities and artificial intelligence — transforming the way people live, work and travel,” Annett said. The UK Space Agency is exploring innovative options for a UK space-based positioning, navigation and timing capability.

HOW LIKELY IS A TOTAL GNSS BLACKOUT?

A failure of all GNSS constellations at once is improbable.

“The higher risk is attacks to GNSS systems from jammers or spoofers,” said Miguel Amor, chief marketing officer for autonomy & positioning at Hexagon, a Stockholm-headquartered information technology company. Anti-jamming and anti-spoofing technologies are available, but have generally been purchased by national security agencies rather than commercial customers, he added.

Regional outages are more common. Geopolitical tensions have led to GPS signal loss near the Middle East. In July 2018, the NATO Shipping Center received reports from ships facing GPS interference while transiting the Mediterranean. NATO also reported similar issues in December 2019 when ships and aircraft in the Mediterranean could not access GPS or GLONASS signals.

A U.S. Transportation Department report delivered to Congress in January identified technologies that can complement or backup GPS service. The report found no current replacement, though, for GPS positioning and navigation capabilities. To ensure resilience, the Transportation Department recommended critical infrastructure owners and operators adopt diverse positioning, navigation and timing technologies.


Anusuya Datta is a Canada-based journalist who previously worked for Geospatial World. Debra Werner, SpaceNews senior correspondent, contributed to this story from San Francisco.

This article originally appeared in the July 2021 issue of SpaceNews magazine.

Anusuya Datta is a writer and journalist with a special interest in Earth observation and sustainability issues. She is based out of Canada, and previously worked for Geospatial World. She is part of the EO4SDG board, and continues to write for several...