InnovationM2MNetworksResearch

Tales In Tech History: GPS

Tom Jowitt is a leading British tech freelance and long standing contributor to TechWeek Europe

A product resulting from the Cold War, the GPS system has transformed people’s lives and indeed journeys

Before the Global Positioning System (GPS) became available to the average man in the street, people had to rely on paper-based maps and street signs, to help them plot their location.

But when GPS was opened to the general public in 2000, suddenly the era of satnav was upon us and getting lost became just a little bit harder.

Cold War

The driving force behind GPS was the US military and the Cold War. The design of GPS was partly based on similar ground-based radio-navigation systems, such as LORAN and the Decca Navigator, used by the British Royal Navy during World War II.

Then in 1959/1960 the US Navy carried out a successful navigation test using satellites (a system called TRANSIT), but the arrival of Russia’s Sputnik sent shivers down American spines and it became the catalyst the drove the creation of the GPS system as we know it today.

Various elements of the US military tested their own GPS systems until the GPS project was officially launched in 1973 by the US Department of Defence. It used 24 satellites and was designed to provide the US military with precise location capabilities. Indeed, GPS was first widely used in the Gulf War from 1990 to 1991.

But GPS potentially had practical uses outside the military, and this became apparent in 1983 when the Russians shot down Korean Air flight 007.

The Korean airline had wandered off course into Soviet airspace and all 269 passengers and crew aboard were killed after the plane was shot down by a Soviet Su-15 interceptor.

Civilian Use

That incident created a tense time during the Cold War, as the Soviet Union initially denied knowledge of the incident, until it later admitted shooting down the aircraft.

However it claimed the Korean plane was on a spy mission and was “testing” Soviet air defences.

© Anterovium - FotoliaFollowing that incident, then US President Ronald Reagan decided to allow civilian commercial aircraft to use the GPS system (once it had been completed) to improve navigation and air safety. Remember, the GPS system was only declared fully operational in 1995.

To receive an accurate location, GPS requires access to four or more medium earth orbit satellites. In 2000, when public access to the GPS had been granted by President Bill Clinton, the US congress also authorised a modernisation effort called GPS III, but this has been badly delayed.

And it is worth remembering that GPS has not been without its problems.

In 2015 the US Air Force uncovered a technical error affecting some GPS satellites that had lain unnoticed since 2013. The problem was apparently caused by the ground-based software used to index messages transmitted by Boeing-built GPS IIF satellites.

And earlier this year disruption to digital radio broadcasts in the UK were blamed on a GPS satellite that caused a software error after the US Air Force removed it from service.

Rival Systems

Another point to note is that United States government still has control of the GPS system. It maintains it, and makes it freely accessible to anyone with a GPS receiver. However, the US government can selectively deny access to the system, as happened to India in the late 1990s.

And GPS is not the only positioning system for this planet.

Russia has its own version called the Global Navigation Satellite System (GLONASS), which had incomplete coverage of the globe until the mid-2000s.

272px-Galileo_logo.svgChina has its BeiDou Navigation Satellite System, while Japan has the Quasi-Zenith Satellite System, and India has the Regional Navigation Satellite System (NAVIC).

The European Union meanwhile has its Galileo positioning system, and its first test satellite was launched in December 2005. Its first operational satellite however was launched in 2011, and as of May this year it has 14 of 30 satellites in orbit (it intends to have 24 operational satellites, six spares).

Galileo is expected to be declared fully operational in 2019.

But GPS came first and is still the satnav system that most of us in our daily lives. It could be argued that mankind’s ability to accurately plot their precise location is one of the most important tech advances in recent times. Strange to think it was a result of the Cold War.

Think you know all about GPS? Try our quiz!