Graphic: Getty Images

Blog Editor’s Note: While not a lot in the below is “newsworthy” for many of our readers, it’s a good compilation. It is also encouraging for all of us to see this issue being framed and presented for a general audience. An audience that, for the most part, has no idea of the vulnerability of GPS and other satnav.

It is also interesting that eLoran is mentioned toward the end of the piece. The UK implemented and certified eLoran for use along its east coast before its European partners shut down their portions of the system. This was to show their unqualified support for the very expensive and, at that time, struggling, Galileo project.

Russia, China, Saudi Arabia, Iran, and South Korea all have versions of Loran in operation. This gives them (and Japan which benefits from coverage by their neighbors’ systems) the ability to weather GNSS problems (solar flare, cyber, deliberate jamming attack, etc.) much better than the US and Europe.

A terrestrial backup will have much more utility than its use for contingencies. To be a good “backup” it will necessarily have much different characteristics than GNSS to ensure it is available when satnav is not. These differences will be leveraged by engineers for a whole new set of PNT tools and capabilities.

But even if “the backup” does nothing more than ensure the safety of hundreds of millions of people against the day space is unavailable, it will be more than worth it. 

Our friend Sally Basker recalls a line from “The Blind Side” – “The first check you write each month is for the mortgage. The second is for the insurance.”

The US and Europe have built very large and expensive houses. Without insurance and an alternative shelter, their populations will suffer greatly in the severe weather to come.

Could the world cope if GPS stopped working?

  • 6 November 2019

What would happen if GPS – the Global Positioning System – stopped working?

For a start, we would all have to engage our brains and pay attention to the world around us when getting from A to B. Perhaps this would be no bad thing: we’d be less likely to drive into rivers or over cliffs through misplaced trust in our navigation devices.

Pick your own favourite story about the kind of idiocy only GPS can enable. Mine is the Swedish couple who misspelled the Italian island of Capri and turned up hundreds of miles away in Carpi, asking where the sea was.

But these are the exceptions.

Devices that use GPS usually stop us getting lost. If it failed, the roads would be clogged with drivers slowing to peer at signs or stopping to consult maps. If your commute involves a train, there’d be no information boards to tell you when to expect the next arrival.

Phone for a taxi, and you’d find a harassed operator trying to keep track of her fleet by calling the drivers. Open the Uber app, and – well, you get the picture.

With no GPS, emergency services would start struggling: operators wouldn’t be able to locate callers from their phone signal, or identify the nearest ambulance or police car.

There would be snarl-ups at ports: container cranes need GPS to unload ships.

Gaps could appear on supermarket shelves as “just-in-time” logistics systems judder to a halt. Factories could stand idle because their inputs didn’t arrive just in time either.

Farming, construction, fishing, surveying – these are other industries mentioned by a UK government report that pegs the cost of GPS going down at about $1bn (£820m) a day for the first five days.

If it lasted much longer, we might start worrying about the resilience of a whole load of other systems that might not have occurred to you if you think of GPS as a location service.

It is that, but it’s also a time service.

GPS consists of 24 satellites that all carry clocks synchronised to an extreme degree of precision.

When your smartphone uses GPS to locate you on a map, it’s picking up signals from some of those satellites – and it’s making calculations based on the time the signal was sent and where the satellite was.

If the clocks on those satellites stray by a thousandth of a second, you’ll mislay yourself by 200km or 300km.

So if you want incredibly accurate information about the time, GPS is the place to get it.

Consider phone networks: your calls share space with others through a technique called multiplexing – data gets time stamped, scrambled up, and unscrambled at the other end.

A glitch of just a 100,000th of a second can cause problems. Bank payments, stock markets, power grids, digital television, cloud computing – all depend on different locations agreeing on the time.

If GPS were to fail, how well, and how widely, and for how long would backup systems keep these various shows on the road? The not very reassuring answer is that nobody really seems to know.

No wonder GPS is sometimes called the “invisible utility”.

Trying to put a dollar value on it has become almost impossible. As the author Greg Milner puts it in Pinpoint: How GPS is Changing Our World, you may as well ask: “How much is oxygen worth to the human respiratory system?”

It’s a remarkable story for an invention that first won support in the US military because it could help with bombing people – and even it was far from sure it needed it. One typical response was: “I know where I am, why do I need a damn satellite to tell me where I am?”

The first GPS satellite launched in 1978 – but it wasn’t until the first Gulf War, in 1990, that the sceptics came around.

As Operation Desert Storm ran into a literal desert storm, with swirling sand reducing visibility to 5m (16ft), GPS let soldiers mark the location of mines, find their way back to water sources, and avoid getting in each other’s way.

It was so obviously lifesaving, and the military had so few receivers to go around, soldiers asked their families in America to spend their own money shipping over $1,000 (£820) commercially available devices.

Given the military advantage GPS conferred, you may be wondering why the US armed forces were happy for everyone to use it. The truth is they weren’t but they couldn’t do much about it.

They tried having the satellites send two signals – an accurate one for their own use, and a degraded, fuzzier one for civilians – but companies found clever ways to tease more focus from the fuzzy signals. And the economic boost was becoming ever plainer.

In 2000, President Bill Clinton bowed to the inevitable and made the high-grade signal available to all.

The American taxpayer puts up the billion-odd dollars a year it takes to keep GPS going, and that’s very kind of them. But is it wise for the rest of the world to rely on their continued largesse?

In fact, GPS isn’t the only global navigational satellite system.


Brad P

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