Q+A: What Is the Future of GPS? Are We Too Dependent?

Geographer Andrew Johnston discusses some of the applications and risks of the satellite-based technology, as well as its future

Is it possible we’re too reliant on this? Images courtesy of the Air and Space Museum

In recent years, we’ve gone from relying on bulky external GPS receivers to having digital maps of the world accessible at our fingertips. But what can we expect in the next few decades from the technology. Andrew Johnston, one of four curators for the new Air and Space Museum exhibit, “Time and Navigation,” says much of the change will likely come from the commercial and social media side of it. Meaning, soon your phone may be getting even smarter. He says, “All that will be invisible for most people. It’s become this sort of hidden utility that everybody uses but nobody really sees it, or understands quite how it works.”

We talked with him about the ubiquity of the technology, what it might look like in the future and whether we’re at risk of being overdependent.

What are some of the applications?

was born as a military system and is still operated by the Air Force in coordination with civilian U.S. government agencies. So there’s lots of applications that are important for strategic directives with the country.

The first thing that people might be used to doing is accessing maps on their phones. That is something that depends on satellite positioning using GPS satellites.

These days, large shipping companies use satellite positing to determine where their trucks are. And you can keep track of all your vehicles from a central location, which is huge for enabling more efficient transportation.

There’s a story in the exhibition about precision agriculture. That’s a huge business now. Satellite positioning has revolutionized how large scale agriculture is taking place. Fertilizer is very expensive, the old way of doing things you would apply the same amount of fertilizer for a whole field. Whereas, now because the piece of farm equipment knows where it’s located and you have a map of the soils and previous season’s crops yields, as the vehicle drives over the field it can actually vary how much fertilizer goes down depending on those conditions.

A firefighter appears in the exhibition highlighting how satellite positioning allows vehicles to get to places faster because they know the routes and have the on-board mapping information. But it also points out some of the things that we can’t do yet, like indoor positioning.

Satellite positioning is also a timing system. It provides high precision time, like an atomic clock, except it’s distributed over large areas. That’s useful for running an electric grid. The way that electricity is transmitted over long distances, you have to time when surges of electricity move from point A to point B and that’s done with GPS timing. Even financial transactions need precise time. Transactions that happen very quickly need a precise time reference, which often comes from GPS.

What are some of the challenges, for example, indoor navigation?

Right now satellite positioning does not work indoors in most situations. Different solutions are being explored. For instance, you can determine your position pretty roughly by using cell phone towers. The phone knows where the towers are located and which towers it is using, so it can roughly determine its position. The level of error is lower when you’re using satellite positioning.

But let’s say you knew which were the closest WiFi hotspots and you knew the information about those spots, and you knew where they were located, you could use that to help you navigate as well, indoors and outside.

Map databases have to be globally consistent so you can move anywhere on the earth and still see the map data, but then they have to be up-to-date and that’s a huge amount of work. One of the ways that different groups are trying to address that is by collecting data and updates from people as they move around with their phones.

It may be possible for a phone to search for hotspots as it’s being carried around and then save this data to a central server. Then subsequent phones, if they’re tapped into the same database, will know the locations of WiFi hotspots.

The commercial aspect is interesting. Throughout the exhibit, there are moments where government funding and competition spurs innovation, is that still the way it is?

When it comes to these global navigation tools, in terms of the funding that makes these systems work, that is still mostly a government story. Systems like GPS, that’s government money that actually makes all that operate.

The thing that’s been going on recently is that there’s a lot of non-government money getting involved in utilizing these services and making derived products, and providing services to individuals all over the world. In other words, there’s this government system that is being run, but then there’s all of these different applications and a lot of the innovation for how to actually use the system is coming from the non-government side.

The American History Museum collaborated on the exhibit, including lending its Stanley car.

While the future of positioning technology in terms of social media is largely invisible, a visible example includes the promise of driverless cars, which Stanley represents in the exhibit. Anything else like that on the horizon?

The possibility of self-driving cars has the potential to transform everyday life. We’ve run out of space to build highways so it’s a possibility of increasing the capacity of the highways that we have by having cars going bumper-to-bumper at 50 miles per hour by getting the human out of the equation. It’s impossible to say how long in the future that will take place. I suspect more than ten years from now that we’ll have lanes set aside for driverless cars but who knows.

The other thing that it will change is how airplanes get around. . .who knows, maybe down the road, human pilots will not be as common as they are today, that’s another possibility.

Concerns? Risks?

Some people do wonder if it’s possible to become too dependent on these satellite-positioning systems, because, what is the backup? The answer today is that for a lot of these services, there is no backup. Now GPS is a very robust system, it’s not going anywhere, but there are some things that make it not work as well. Down the road, we have to worry about things like solar interference and make sure the radio spectrum is free of other signals. We have to worry about jamming. Although it is illegal to do so–GPS is shockingly easy to interfere with by someone determined to block the system or create problems.

Has it happened?

One of the famous examples was at Newark Airport. A few years ago a new airport positioning system was being tested. Every so often, the GPS would stop working briefly. They finally figured out that what was going on was that right next to the airport was the New Jersey Turnpike. A truck was driving by with a GPS jammer to prevent the central office from tracking the movements of this truck. The jammer plugs into the power adapter and GPS doesn’t work for the vehicle. The problem is that it affects a zone much bigger than a truck, including, in this case, the grounds of the airport.

There actually are ways to provide backup to global positioning, including ground-based transmissions. For instance, the LORAN system was made up of ground-based radio transmitters that allowed you to determine position. That system was mostly shut down and many people are not happy about that because they ask the question–”What’s the backup to satellite positioning?”

The new generations of GPS satellites being developed right now will include features that will protect the signals and make them even more useful for users all over the world. I think right now, the robustness of the GPS system is such that we’re not in any kind of danger zone, but I do think we’ll see a push for a ground-based backup.

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