Clear and Present Economic Danger

Americans depend on GPS. While military dangers are obvious, outages would also cause incalculable damages to the economy.

By Diana Furchtgott-Roth

Former Deputy Assistant Secretary for Research and Technology | Department of Transportation; and
Adjunct Professor | George Washington University

Vadimir Putin’s Russia brags that his country’s new Pole-21 radio-electronic systems, soon to be installed in Siberia and the Ural Mountains, can spoof America’s Global Positioning System (GPS), which provides positioning, navigation, and timing services through a system of satellites, and is vital to Americans. Hacking it has never been easier.

Originally invented for the military, GPS was extended to civilian use by President Ronald Reagan in 1983 after the Russians downed a Korean Air Boeing 747 that had accidentally strayed into Soviet airspace, killing all 269 people on board, including Representative Larry McDonald, a Georgia Democrat.

GPS is increasingly open to hacking, as sophisticated technology has become cheaper and more widely available. In 2019, Iran spoofed the navigation system of British tanker Stena Impero in the Strait of Hormuz. The ship’s crew thought they were in international waters when they were actually in Iranian territory. The ship and its crew were held for 10 weeks by Iran.

Damage to GPS systems has in the past, and easily could in the future, come from harm to satellites — hacking and spoofing, as well as interference from activities close to the GPS band. The economic consequences of each are so large and ubiquitous as to be immeasurable. That is why Congress has requested three separate laws that require the transportation department to put in place backups to GPS. However, Congress has not yet appropriated the funds to do this.

Potential threats to GPS

GPS satellites could be damaged by electromagnetic storms or hostile military action, either of which could eliminate the signals. But even with satellites in place, hacking incidents proliferate, and inexpensive hardware equipment to do so is easily available online. Today, GPS outages and gaps are real, not hypothetical. The Coast Guard collects reports of gaps in GPS coverage all over the world. Examples in the last months of 2020 include ships in the Mediterranean and the Gulf of Suez, surveyors in Bull Lake Dam in Wyoming, and a driver in Seattle. The accident in the Suez Canal with the Ever Given was not due to GPS spoofing, but many pilots report GPS outages in that region. That accident cost international commerce billions of dollars in delays.

Damage to GPS systems has in the past, and easily could in the future, come from harm to satellites — hacking and spoofing, and interference from activities close to the GPS band.

GPS outages are not merely accidental. Criminals hijack trucks, steal cargo and ship stolen vehicles in containers by using GPS jamming to disable tracking devices. Truckers can interrupt port operations by bringing GPS jammers into a port area to defeat fleet tracking systems. Dangers also arise to GPS from federal the spectrum policy. The Federal Communications Commission (FCC) in April 2020 unanimously granted an application by Ligado Networks, based in Reston, Virginia, to offer a ground-based service in spectrum, much of which is next to spectrum allocated for GPS.

Ligado’s signals are 2 billion times as powerful as GPS signals. Just as an outdoor concert drowns out birds’ songs, the proposed Ligado 5G transmitters would overwhelm GPS signals. Federal government studies indicate major disruption to GPS (see
Ligado says it will use the newly allocated spectrum for faster 5G Internet service. However, Ligado’s spectrum is ill-suited to 5G. It is not part of the FCC’s comprehensive 5G plan; it is not included by any international 5G standards bodies for 5G; it is not international all harmonized for 5G; and no carrier has expressed an interest in its licenses.

In an unprecedented move, the National Telecommunications and Information Administration (NTIA), on behalf of the entire executive branch, asked the FCC to reconsider, citing “irreparable harms to federal government users of the Global Positioning System.” As part of its approval, the FCC required Ligado to replace the federal equipment that would be damaged through its operations. But Ligado was not required to pay for private sector equipment, such as car navigation systems, surveying equipment, and general aviation navigation devices.

Economic consequences

Congress placed the Transportation Secretary in charge of civilian GPS because GPS is vital to transportation. Americans use over 900 million GPS receivers in cell phones, car navigation systems, emergency vehicles, commercial trucks and buses, and railroad operations (that is nearly three receivers for every man, woman and child in the United States). Over 100 million vehicles have car navigation systems. Ships, planes, and drones use GPS for navigation; trucks use GPS for location services and driver safety.

A security forces airman sends a message from his patrol vehicle at Eglin Air Force Base. The tablet-based communication system in his vehicle quickly provides GPS and data access


The United States has about 7,600 commercial aircraft. In addition, there are 167,000 general aviation aircraft and 10,000 rotorcraft, as well as 34,200 experimental aircraft. They use GPS to navigate to and from airports. There are many types of GPS receivers including panel mounted units, handheld units, and now GPS is incorporated even into electronic flight bag systems. Instrument Flight Rules (IFR) GPS receivers require the additional accuracy of WAAS GPS equipment for take-off and landing approaches to airports. All of these systems are used for navigation, charts, and flight information and safety. 

This year, pilots experienced a loss of GPS signal approaching Wilmington Airport in North Carolina. The Federal Aviation Administration (FAA) traced outages to wireless signals from the local utility’s smart grid system. “It is scary to lose your GPS signal just a mile and half from the runway, it is a critical time during the approach,” Thomas Goodwin, Founder of the Wilmington Pilots Association, told me.

Road transportation

Modern emergency responders use GPS, rather than maps, to locate accident sites and to get people speedily to the hospital. Emergency responders include police, firefighters, and ambulances — both public and private, as well as private services to assist drivers whose vehicles have malfunctioned. Examples are the American Automobile Association, different insurance companies, and auto manufacturers that insure and track their new vehicles with services such as GM’s Onstar and BMW’s BMW Assist. In 2019, the latest year of normal traffic before the pandemic, American drivers lost more than $88 billion due to traffic jams, according to research firm INRIX. Pollution and accidents add additional billions of dollars every year.

Captain John Smith, a member of Tulsa Firefighters Local 176 in Tulsa, Oklahoma, uses GPS to find the fastest route to a fire. He can’t be stuck at a red light or trapped in a traffic jam when someone’s home is burning. According to Smith, a fire can double in size every two minutes. “If we get stuck behind traffic, it can significantly delay us and give that fire time to grow,” he said.

Over 100 million cars in the United States come with GPS-enabled devices, performing a variety of functions. Navigation systems enable drivers to see where they are going. Telematic systems notify drivers when automotive maintenance has to be performed and alert first responders if a car has broken down. The transportation department estimates that about 8.5 million medium and heavy trucks have GPS. In addition to navigation, GPS receivers in trucks are used for fleet management, driver routing, and electronic logging devices. Electronic logging devices are required to make sure that drivers do not drive for more than a certain number of hours without taking rest breaks.

Electric, hybrid, and autonomous vehicles use GPS to measure battery charge percentage and charging status. This is especially important for fleets of taxis, buses and trucks, which are the most promising new opportunities for autonomous vehicles. As connected and autonomous vehicles mix with non-automated vehicles, position and timing become increasingly critical. New fuel-saving technology in gasoline-powered vehicles also depends on GPS. When vehicles switch off at red lights, they are still operating. Sophisticated GPS systems need to be able to distinguish the stopped vehicle at a traffic light from the one that is parked nearby. Furthermore, electric vehicles and charging stations require GPS for navigation. When you are driving down the highway and your battery runs low, you may well need GPS to get to a charging station.

The United States has about 7,600 commercial aircraft. In addition, there are 167,000 general aviation aircraft and 10,000 rotorcraft, as well as 34,200 experimental aircraft. They all use GPS to navigate to and from airports.

Rail and maritime

GPS is used for both the operation and maintenance of rail systems. Positive train control, which uses GPS, operates on all 58,000 freight and passenger routes, including Amtrak and commuter rail. Required by Congress, the new technology stops trains from crashing into each other, speeding, accidentally going into work zones, and entering no-go track zones through switches left in the wrong positions. In addition, GPS is used both to test for broken rails in conjunction with laser systems and to assess geometry failures in a railroad track. It is used to operate drones used for maintaining tracks and bridges.

Ships are dependent on GPS for navigation. GPS provides information about speed, steering, radar, electronic charts, the Electronic Chart Display Information System, and under keel clearance data to prevent ships running aground. Ships’ automatic identification system incorporates receivers and allows port and marine authorities to track locations of different vessels. VHS radio communications allow ships’ crews to communicate directly by voice.


Geospatial technologies, which use GPS, have revolutionized surveying and construction. Surveyors use these new technologies to take measures that are beyond line of sight, either from survey stations, or by carrying GPS devices in backpacks. GPS is particularly important in measurements of coasts, remote mountain areas, and waterways, which have fewer reference points.

Construction companies use 3D laser scanning, mobile mapping, remote sensing, and tunneling. Digital blueprints can guide the locations of studs and nails, reducing errors and repeat work. GPS digital construction lowers the cost of building new highways and makes federal infrastructure dollars go further.

GPS-enabled tractors made by John Deere and others reduce the amount of added water and fertilizers by treating individual seeds in precise locations. Precision agriculture uses GPS technology to place seeds in precise locations. Then, these seeds can be fertilized, watered, and sprayed with insecticide, reducing the use of these products. Drones can work during fog and darkness to perform these tasks.

In July 2020, 27 representatives from the House Agriculture Committee wrote to FCC Chairman Ajit Pai to reconsider allowing Ligado Networks LLC to operate a terrestrial network. The committee members wrote, “During planting season, if GPS were interrupted, the economic impact to the agriculture sector could amount to losses of $15 billion due to lower crop yields.”

Electric power plants rely on GPS technology to synchronize generators and distribute energy to the grid. To prevent blackouts, electric utility operators use GPS timing services for synchronizing their generators with the grid. Only with such synchronization can utilities incorporate power from wind, solar and traditional sources. Monitoring devices rely on timing signals from GPS to provide power to different places on the grid.

John Deere’s StarFire GPS receivers used NASA’s global network of ground stations and the JPL software. Accurate GPS helps farmers manage their fields, for example enabling more accurate observations and crop mapping

Climate Change

GPS has become the basis for measuring Climate Change, and interference with GPS will affect scientists’ ability to determine how the climate is changing. University of California at San Diego scientist Susheel Adusumill, lead author of a study on the measurement of ice mass in West Antarctica, said that GPS was vital to his work on the relation between snowfall and ice mass. “Without GPS, the satellites wouldn’t have given us the right answer.”

With GPS radio occultation, terrestrial weather is fed into Climate Change models to improve their accuracy. This technique is the lynchpin of weather forecasts, and any interference with GPS will devastate that technique. GPS radio occultation calculates pressure, temperature, and water vapor in the lower atmosphere. At altitudes below 10 kilometers, it can measure the amount of water vapor in the atmosphere. Between 10 and 30 kilometers above the Earth, it can measure temperature altitude profiles. Between 30 and 50 kilometers up, it can measure density and pressure.

Reflectometry, another GPS-based technique, measures changes in snowfall over the US, vegetation in the Amazon and ice coverage at the poles, soil moisture, and sea surface roughness and height. A lot of climate monitoring is done by the National Oceanic and Atmospheric Administration (NOAA), and interference with GPS would limit its ability to perform studies.


When the first computers were invented, no one saw a need for the now-ubiquitous anti-virus software. Similarly, GPS was free from hacking in its early days, but now lawmakers realize that protection is needed. Three separate laws, most recently the Frank LoBiondo Coast Guard Authorization Act of 2018, tasked the transportation department with providing a backup to GPS. The LoBiondo Act required the Secretary to put in place a backup system for GPS by the end of 2020, subject to Congressional appropriations.

A report describing different technologies to back up GPS capability was published by the transportation department in January. Although no funds from Congress have been appropriated, DOT’s new report lays out a roadmap. DOT meticulously tested 11 different technologies that could be used in the absence of GPS signals, including terrestrial radio signals, fiber networks for timing, Iridium satellites for encrypted signals (which would be damaged by Ligado transmitters), and Wi-Fi and cell signals for localization. The report concluded that a variety of technologies should be used to complement GPS due to multiple landscapes. Long-range broadcast beacons situated on buildings or telephone poles perform well in cities, and low Earth orbit satellites do better in rural and maritime areas.

In addition, President Joe Biden should ask the FCC to reconsider approval of Ligado’s petition for a ground-based network close to the GPS band of spectrum. Americans depend on GPS. Outages could cause incalculable damages to the economy. Waiting for it to fail, or for hostile powers to spoof it, is waiting until it is too late.

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