GPS Explained: where did it come from, and how does it work?

Global Positioning System technology has allowed consumers to easily pinpoint their location, anywhere in the world. You’ll find it on just about every modern smartphone, as well as built into many modern cars. 

But where did this technology come from, and how, exactly, did it work?

Cold War Origins

In 1957, the Soviet Union launched its Sputnik 1 satellite. It lasted for just a few months before falling back to the earth, but its impact on the subsequent space race was lasting and profound. Among the many ripple effects was the creation in the 1970s of a network of several dozen satellites by the US armed forces, collectively known as the Global Positioning System. 

The key to the technology’s success was the ability of the satellites to transmit radio signals, including time-code information. Once the receiver got hold of a signal from a satellite, along with the time, it could use that information to determine how far the signals had travelled, and thus how far away the satellite was.

This system relied on high-precision radio waves in an age where modern RF connectors and shielding had yet to come to be. Moreover, for this system to work, an entirely new kind of clock had to be invented – as the existing quartz clocks were not accurate enough, and were vulnerable to quantum effects. We’re talking here, after all, about very fast signals. Fortunately, the answer came along in the form of the atomic clock, which was much more accurate. 

Relative Time Differences

Einstein’s theories of relativity predicted that the clocks running on the satellites would run faster than clocks on earth, by a few microseconds each day. Over time, these differences would cause the GPS to create significant errors. Once this discrepancy was compensated for, however, the technology began to work flawlessly.

Consumer GPS

In the 1980s, GPS began to become affordable enough for private companies to take advantage of it. The very first civilian-targeted system was the NAV 1000, which launched at the end of the decade, and cost several thousand dollars. It was pitched at hikers and adventurers who might want to know where they were – but there was no colour display, only an alphanumeric display- which meant that you’d need a pen-and-paper map to get the best from the device.

GPS Today

Today, GPS technology forms the backbone of commercial fleets. With its help, fleet managers can track every vehicle in a given fleet. Not only that, but they can monitor driver behaviour through telematics, and alert drivers to changes in route if there are problems on a given road. These efficiency savings, while often marginal in isolation, accumulate to create the modern, next-day-delivery logistics industry that we recognise today.