Skip to Content

Has GPS Lost Its Way?

After 20 years of plodding development, the Global Positioning System remains a novelty for niche markets. The system’s future hinges less on technology than on politics, economics and human nature.

In 1982 Charlie Trimble, a Silicon Valley entrepreneur, paid Hewlett-Packard $80,000 for the remains of a canceled engineering project-shelves full of research notes, and the result of that research: a circuit board the size of a coffee table. The circuit board could pick up a signal from the first satellite in what would eventually become the Navstar Global Positioning System (GPS), a ring of 24 military satellites orbiting 18,000 kilometers above the earth.

Trimble’s company, Trimble Navigation Ltd., has since shipped GPS receivers for applications as varied as tracking wild goats in Galapagos and measuring tectonic movements atop Mount Everest. In 1991, Trimble sent $7 million worth of receivers to Gulf War GIs. Trimble’s principal competitors began their careers working for him before founding their own companies. And after nearly two decades of evangelizing, Trimble still hasn’t lost his enthusiasm for the technology-there’s not a trace of doubt in his voice when he lauds GPS for doing everything from ending world hunger to winning the Cold War. “Knowledge of position has tremendous benefits-to feed the world, to provide more efficient commerce and therefore better quality of life, to provide better safety and security,” he says.

On the other side of the country from Charlie Trimble’s office, in Lowell, Mass., Charley Richardson, director of the Labor Extension Program at the University of Massachusetts, has spent just about as many years studying the effects of technology on the workplace as Trimble has developing and selling GPS receivers. Richardson recently completed a study on the effects of GPS-enabled monitoring in the transportation industry. He believes GPS can lead to gross violations of an individual’s right to privacy, a problem that he believes far overshadows the technology’s potential for good.

Between these two extremes lie the rest of us, most of whom haven’t really thought all that much about GPS. This is, after all, a technology that has been touted for the past 20 years as being on the verge of changing the world, but which somehow never quite meets the expectations of shareholders, pundits or the press.

The idea is simple: when a GPS receiver picks up satellite signals, it calculates its position based on its distance from each satellite. A receiver needs three satellites to get a fix on its latitude and longitude; to give an extra measure of reliability, and to determine altitude as well, the unit needs to fold in a reading from a fourth satellite. A constellation of 24 satellites gives round-the-clock, global coverage.

Creating this system was an elegant feat of engineering, but the public has managed to restrain itself from buying in. In 1991, after the Gulf War victory, commercial applications like in-car navigation were expected to rocket to an $8 billion annual U.S. market; instead, people bought road maps. The domestic GPS market finally inched over $1 billion in 1997, according to Mountain View, Calif.-based market research firm Frost & Sullivan. Last August, Trimble was removed as CEO of the company he founded by his board of directors, after several quarters of disappointing sales. When it comes to the effect GPS will have on our lives, both Trimble and Richardson are speaking in the future tense.

The history of GPS is a classic case of technology in search of a market; the future of GPS will have less to do with technology than it does with politics, with economics and with simple human nature.

Tapping the Military’s Assets

It’s human nature, for example, to want something for nothing. The GPS network was developed for the military. Civilian usage was an afterthought. The Department of Defense (DOD) put limits on the accuracy of the civilian signal to protect national security, a practice the Air Force euphemistically calls “selective availability.” The satellites were paid for and are maintained by the military as a way for missile strikes to be launched with precision on military targets, using a technology based on triangulation.

“It was developed as a military system, and never intended for commercial use,” says Aaron Renenger, spokesperson for the GPS Joint Program Office at the Los Angeles Air Force Base. “It allows us to guide bombs to target within meters of accuracy, or to guide our soldiers on the ground. But in addition to the military use, we’ve now become stewards of a global utility for civilian applications. It’s a struggle to satisfy all of the competing interests.”

Commercial GPS businesses benefit directly from free use of the $17 billion in assets currently in orbit, plus an additional $500 million that DOD spends to monitor and maintain the satellites. Unlike other satellite-based industries, GPS vendors can be confident these assets will be maintained even in the event of damage from meteor showers or other acts of God. Furthermore, purchasers of GPS receivers benefit from having a free signal: There are no monthly service fees for accessing GPS.

Locating a Market

Having access to $17 billion in capital equipment has also led the commercial GPS industry to develop technology solutions well before the market asked for them, at price points too high for the demand. GPS was a natural enabler for ocean navigation, where Trimble Navigation made its first mark, and for desert warfare, where flat horizons permit access to up to 12 satellite readings at once. Beyond these applications, handheld GPS receivers for consumer use have been niche-marketed to death-for golfers to measure their drives, for hikers to find the trail, and for the devout to find the precise direction to Mecca. Receivers have replaced Mont Blanc pens as the corporate novelty gift of choice. But this splintered market has not led to a robust industry. “The problem with this stuff is how to make money from it,” says Tom Starnes, director of embedded microcomponents at Dataquest, a market-research firm in San Jose, Calif. “Just because a technology is feasible doesn’t mean I’m going to pull my wallet out and buy it.”

The signal provided by the DOD network has also proven to be too inaccurate for many commercial applications. Even without the intentional degradation of the signal that civilian users must suffer, the basic GPS network only provides accuracy to within seven to 10 meters. That’s sufficient if your aim is to bomb a military installation, but totally inadequate if you’re trying to locate a fire hydrant hidden in a field of weeds. And the signal that civilians receive can reliably tell your position only to within 70 to 100 meters. Hikers have died in Alaskan snowstorms, so trusting of their handheld GPS receiver that they continued to search for the shelter they knew was agonizingly near, instead of digging in and saving themselves. Others have walked off precipices in Scotland in the fog.

A technical solution known as differential GPS uses an earth-based receiver/transmitter at a previously surveyed point, which can receive the satellite signals, compare the GPS-determined location with the actual location, calculate the error, and broadcast corrections to handheld receivers in the vicinity. In 1994, Ashtech implemented such a system for the Coast Guard, providing accuracy to within a few meters along the entire coastline of the continental United States, sections of the Mississippi River basin, the Great Lakes region, Puerto Rico, and portions of Alaska and Hawaii. Trimble Navigation, Ashtech and a third company, Novatel, also market differential GPS packages including portable transmitters that can be placed over a surveyed site, providing location information with a margin of error measured in millimeters.

“In the commercial market, accuracy is addictive,” says Trimble. “To get to the level of accuracy people demand, you need differential techniques. Selective availability really isn’t a factor anymore, since even without it the accuracy would not be precise enough. It’s a completely different problem from the one we were trying to solve when we began the company.”

After 20 years of battling government interference and disappointing growth, two developments are finally giving the commercial GPS industry reason to hope. The first is the sinking price of GPS-enabled chip sets, which are following Moore’s Law with a vengeance and will soon be available for about $10. With basic hardware that cheap, it becomes economical to embed GPS in cell phones, pagers and dashboards, without significantly raising the price of these items. “What held up market adoption had nothing to do with GPS,” says Dave Nelson, director of GPS programs at the Aerospace Corp., an organization that works with the Air Force to maintain and develop GPS satellites and ground-based support. “It has more to do with getting the cost down so any consumer wants it, instead of just being something attractive to gadget freaks.”

The second development in GPS’s favor is the rise of complementary technologies such as digital mapping and wireless communication. Digital mapping translates GPS’s latitude and longitude readings into something useful. For many of us that means dashboard displays that show where we are and how to get where we’re going. For farmers, the combination of GPS and geographical information systems helps pinpoint the yield effects of fertilizer application down to the square meter, thus lowering fertilizer use, reducing pollution from runoff, and increasing yields. And communication networks in combination with GPS allow for a new range of applications, from tracking fleets of taxis to locating your lost child in the mall by paging her. The first widely adopted communication-based application for GPS will likely be a national emergency service that pinpoints the location of cellular phones calling 911, mandated by the Federal Communications Commission to be in place by 2001.

It’s the communication-based GPS applications that really energize Trimble. “The most exciting application of GPS in my mind has to do with the guidance and control of mobile platforms,” he says. “To get to there, we need to integrate with allied technologies. What’s truly valuable isn’t GPS, it’s knowledge of position. GPS is just a fundamental way to get there.”

The value of such GPS systems are clear, agrees Ron Stearns, an analyst for research firm Frost & Sullivan who has studied the GPS market. Stearns argues that “the benefits are very easy to see in the area of emergency response, where you can better direct available emergency response vehicles to a location.” Indeed, according to Stearns, communications-driven applications will fuel the GPS market, which Frost & Sullivan predicts will grow at a steady 20 percent over the next few years.

But when you start to link GPS with communications networks that monitor movements remotely, some folks get nervous. The same technological infrastructure that makes it so easy to manage physical assets, like truck fleets and boxcars, can also be used to monitor human activity. Is this an intrusion society is willing to invite? The idea of “being watched all the time” bothers the University of Massachusetts’ Richardson.

Remoteness Disappears

The first to feel the effects are those whose work has traditionally brought them far from the eyes of supervisors. With GPS, that remoteness disappears. Says Richardson: “A direct effect of GPS monitoring is that you can identify any place where there might be slack in the system. If a shipper has a loading dock that backs up, he can divert trucks to another dock. What that means for the trucker is that a natural break in his work is being taken out. His control over the day is taken away, and there is an intensification of the work day as a result of the technology.”

Differences of opinion like these led to the 1997 strike at United Parcel Service. An early adopter of many information technologies, the company thought GPS would be an efficient way to keep track of its fleet from a central location. In 1996, UPS began equipping its trucks with GPS receivers that could be monitored from a central location. Employees thought poorly of the idea. The current contract between UPS and the International Brotherhood of Teamsters forbids GPS to be used continuously, or for evaluating employee performance.

“We weren’t at all opposed to the technology, as long as it helped our workers to do their jobs better,” says Paul Boldin, research director for the Teamsters. “GPS is useful as a way to optimize routes, but for that purpose it doesn’t need to be done continuously. Guys at UPS are working their butts off, running from stop to stop. They don’t need the additional hassle of being tracked. If the work is not getting done, it’s going to show up in late deliveries and poor customer feedback. GPS in that case is overkill.”

When we use the Internet these days we don’t think much about the technology’s origins as a defense communications network. GPS however is still, at its heart, an enabling technology for war. Though the system now in place represents the combined effort of public and private innovation, national security is its bedrock mission.

Still, encouraging changes are on the way. In 1996 President Clinton ordered the U.S. military to cease its policy of intentionally degrading civilian GPS signals by no later than 2006. The Pentagon will, however, retain its capacity to degrade the signal for purposes of national security in specific regions. During a future war in the Balkans, for instance, the U.S. military will be able to distort the location information just in that region, while leaving other parts of the world unaffected.

The consumer market will see other improvements as a new array of 24 satellites is deployed. The new models-scheduled for launch between 2003 and 2010-will transmit civilian location signals at not one frequency but two. This additional frequency will allow the GPS receiver to detect and then compensate for distortion of the GPS signals as they pass through the atmosphere. (The military will continue to operate its own separate GPS frequency, to which civilian receivers will not have access.) Meanwhile, improvements in algorithms will eventually allow GPS to be used even in urban canyons and dense foliage, areas where it’s currently weak. Startup companies such as SnapTrack in San Jose, Calif., are already marketing their GPS devices specifically for use in city centers.

Even with such gains, it is by no means a foregone conclusion that GPS will become a ubiquitous utility. Evidence to date suggests that phenomenally accurate location data are of interest mainly to specialized niche markets. Enthusiasts like Charlie Trimble argue that the falling price of the hardware will lead to a new era of location-awareness, with GPS receivers embedded in scores of everyday objects much the way clocks are now. But is this information valuable? Is it useful to the average consumer? Those are the kinds of questions that will determine the future of GPS, a system that has been “on the horizon” for a long time now and doesn’t yet have a clear route home.

Keep Reading

Most Popular

Large language models can do jaw-dropping things. But nobody knows exactly why.

And that's a problem. Figuring it out is one of the biggest scientific puzzles of our time and a crucial step towards controlling more powerful future models.

The problem with plug-in hybrids? Their drivers.

Plug-in hybrids are often sold as a transition to EVs, but new data from Europe shows we’re still underestimating the emissions they produce.

Google DeepMind’s new generative model makes Super Mario–like games from scratch

Genie learns how to control games by watching hours and hours of video. It could help train next-gen robots too.

How scientists traced a mysterious covid case back to six toilets

When wastewater surveillance turns into a hunt for a single infected individual, the ethics get tricky.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at with a list of newsletters you’d like to receive.