The Royal Academy of Engineering says that developed nations are “too reliant” on GPS [via SlashDot]:

While most people equate GPS systems with the tiny screens which get drivers from point A to point B, the report says society’s reliance on the technology goes well beyond that. The Academy says the range of applications using the technology is so vast that without adequate independent backup, signal failure or interference could potentially affect safety systems and other critical parts of the economy.

[…]

In the U.K., on top of satellite navigation, GNSS is used for data networks, financial systems, shipping and air transport, agriculture, railways and emergency services. The European Commission recently estimated an €800 billion ($1.1 trillion US) chunk of the European economy is already dependent on GNSS.

The vulnerabilities in these systems, the Academy says, could have dire consequences if exposed.

But why worry, right? So long as we keep the satellites maintained, everything will be fine… though we do need to trust in the good will and continuing stability of the US Air Force for that, at least for now.

Well, actually, keeping the satellites running is only part of the game. You see, GPS signals can be jammed pretty easily, and cheaply too [via Jamais Cascio]:

Though illegal to use in the US, UK and many other countries, these low-tech devices can be bought on the internet for as little as $30. Sellers claim they’re for protecting privacy. Since they can block devices that record a vehicle’s movements, they’re popular with truck drivers who don’t want an electronic spy in their cabs. They can also block GPS-based road tolls that are levied via an on-board receiver. Some criminals use them to beat trackers inside stolen cargo. “We originally expected that jammers might be assembled by spotty youths in their bedrooms,” says Last. “But now they’re made in factories in China.”

Last is worried that jammers could cause as much havoc on land as he discovered on the Galatea, and he’s not alone. In November 2010, a NASA-appointed executive committee for “space-based positioning, navigation and timing” warned that jamming devices could cause disaster if activated in cities. It is not known how many are out there, but the panel is concerned that the risk of interference is growing fast. And in future, devices called “spoofers” – which subtly trick GPS receivers into giving false readings – may make the problem even worse…

Repeat after me: Everything Can And Will Be Hacked. But the Royal Academy’s warning is worth considering; we’re at a civilisational stage where a global positioning system is a necessity. The problem with GPS is its hierarchical structure: everything depends on the sats, which are rather hard (and expensive) to maintain. I’m no expert on this sort of thing, but shouldn’t it be possible to build some sort of surface-based network that can achieve a similar result? Some smartphones can do rough positioning by signal triangulation, and I’m betting you could find a way to make that method more effective and widespread for the same budget as a few satellite launches.

That said, there’s a whole lot of the planet that doesn’t have cellphone towers (the oceans, for a start), so ground-based systems are always going to be a crude and limited second-tier fallback… if I was working for a commercial space outfit right now, I’d be keeping the necessity for GPS maintenance on the boardroom whiteboard as a potential revenue stream.