Nervous System: Knowing Your Place in the World

The use of GPS systems to track location may seem ubiquitous today. But as David Kalat reveals in this month’s history of cybersecurity, it’s a relatively recent phenomenon, dating back to one fateful airline disaster at the height of the Cold War.

Use of Global Positioning System (GPS) satellites to pinpoint the location of just about anything on Earth is now so routine and ubiquitous it can be hard to remember it is both a recent development and a circumstantial oddity. That the average person can easily determine her exact location on the globe at any moment, casually and without fuss, is in many ways a consequence of the fact that a group of people once got badly lost and paid a terrible price.

On September 1, 1983, Korean Air Lines flight 007 was returning to Seoul from New York. The plane drifted from its intended course, however, ending up in restricted Russian airspace near highly secure military installations. The civilian flight went some 200 miles off course. Soviet fighter jets intercepted KAL007. After failing to receive a reply, one of the Soviet pilots launched two heat seeking missiles. The plane was destroyed, killing all 269 people on board.

In the aftermath of the tragedy, the Russians downplayed the incident, noting simply that an unidentified aircraft had been shot down in restricted airspace. The United States played up the incident, accusing the Soviets of a “massacre.” Agreements were canceled, military officers were fired, diplomats tried to calm shattered nerves. These were the usual sorts of institutional reactions to a public catastrophe.

At the same time, something unexpected also happened. The US announced that it would make its experimental new satellite-based navigation technology available for civilian uses around the world. No civilian flight should ever have to risk going so disastrously off-course again.

To put this announcement into context, the technology in question involved an ongoing and expensive endeavor of research and development by the US military to achieve a specific battlefield advantage, and here was the administration of fabled Cold Warrior Ronald Reagan reacting to an act of aggression by the Soviet military by declaring that this secret weapon would be made public.

In fact, the very concept of using satellites to locate objects on Earth had emerged from the American military reaction to the Soviet launch of the Sputnik satellite in 1957.

A team of scientists at the Applied Physics Laboratory had been tasked with monitoring Sputnik’s transmissions. They observed that the signal’s broadcast frequency fluctuated as the satellite moved through the sky—rising as the satellite got closer, lowering as it receded. This distortion is known as the Doppler effect. Since the scientists already knew where they were, measuring the extent of the Doppler effect’s frequency distortion could tell them where Sputnik was.

This opened up the intriguing notion of reversing that technique. If one knew the location of a satellite in the sky, the Doppler effect could be used to determine the corresponding location of a terrestrial receiver.

The military uses of such technology were immediately apparent. The ability to map with pinpoint accuracy the locations of objects on the ground would vastly improve missile targeting capabilities and troop movements. The emerging defense industry of the mid–twentieth century began pouring money and resources into developing a global satellite-based navigation system.

The first iteration of this technology emerged in the 1960s under the name “Transit.” With only five satellites in orbit from which to calculate positions, Transit allowed a user to get a fix on his location that updated roughly every hour. To make the system more robust would mean putting more satellites into orbit.

That next iteration would be known officially as Navigation System using Timing And Ranging (NAVSTAR); this is the system now widely known colloquially simply as “GPS.” In all, the Department of Defense would launch twenty-four NAVSTAR satellites into the skies between 1978 and 1993 to complete the network, providing uninterrupted worldwide navigational coverage. Between the first and last NAVSTAR launches came the fateful flight of KAL007.

The technology had been developed for military purposes. No civilian uses were imagined, nor was the military predisposed to share this secret weapon with potential enemies. If not for President Reagan’s reaction to the KAL007 disaster, the world of modern telecommunications and information technology could have looked very different.

The principal technology that underpinned the 3G era of cellular telephone service relied on the availability of GPS data. Known as “Code-Division Multiple Access,” or CDMA, this technology allowed cellular telephones to share a limited bandwidth by breaking up each handset’s transmissions to the cellular towers, shuffling the fragments in with other handsets’ broken-up transmissions, and then reconstituting the pieces at the tower. However, this technique required the individual cellphones to boost or reduce their power continually to maintain a constant signal strength over time, regardless of the device’s distance from the tower. This was possible only if the handset had a means of determining its physical location. Consequently, GPS chips became embedded in cellphones as a necessary element for the device’s basic functions, which in turn provided the opportunity for other software developers to find additional uses for that already-present feature. Meanwhile, the competing European satellite navigation system Galileo was launched so that European cellphone companies would not find their technology dependent on a largesse of the American military that could be revoked on a whim.

Interestingly, Reagan’s 1983 announcement had never specified that the technology would be free for civilian use, and for that matter the only civilian use his administration had explicitly mentioned was aviation. Nonetheless, the technology proved to be so expansively useful that there was no real opportunity to put the genie back into the bottle. GPS technology now is integrated into vast swaths of the economy, from farming to finance. The same technology that allows smartphone users to tag their photos with the location where they were taken also aids people in finding lost pets, forecasting the weather, surveying land, scheduling international money transfers, and of course facilitating computer-aided personal navigation.

 

The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions, position, or policy of Berkeley Research Group, LLC or its other employees and affiliates.