Our smartphones are packed with sophisticated and high end technologies that help us to do different kinds of work and to enjoy these features we have to pay money. But there is actually a piece of technology that is free and also extremely important for other features to function properly. It is called GPS or Global Positioning System.
As we all know, the GPS belongs to the United States federal government, which was launched in the late 1970s to aid the USAF to provide air superiority. Initially named as the Navstar GPS, the entire network became fully operational only in 1995, after 20 years of its first launch.
Over the years, more than 4 dozen of GPS satellites were launched in different blocks, a new one goes in and the older one retires. The initial cost of the satellite launches was more than $2 billion, with few millions a year to keep them working. As we mentioned earlier, nothing is for free, but how come this is free? We use GPS everyday right, and still we don’t have to pay anyone. Well, it is technically free and not free at the same time. Let me explain.
How GPS is Free of Cost? Or is it really Free?
Today, GPS systems play an important role in our lives, with the help of this technology, we can go anywhere we want without getting lost, locate anyone and in the future we might be able to build fully drive-less cars. Currently, with an appropriate ‘hardware’ anyone-anywhere can use it for free, but this wasn’t the case three decades ago.
One particular event made it happen. In the midst of Cold war, in 1983, a Russian fighter Su-15 shot down a Korean passenger jet which deviated from its planned flight path and entered into the prohibited Soviet airspace. This acted as a fuel to already burning house, there were many assertions made and one of those was that availability of a modern navigation technology could have averted this event. In response the United States president Ronald Reagan declared GPS free for all but with a twist.
The signals used by other nations and non-military departments in the United States will have a decreased accuracy of 100 meters, which will give US forces an upper hand while still useful to common public but not by modern standards.
It was only in 2000, when the government made accurate GPS tracking available to all people in or out the United States, after president Bill Clinton signed a bill to stop the restriction. One of the main reasons behind this move was to benefit tech based firms in America. Back to the initial question – is GPS free? Well, it’s not. Each year, US citizens pay more than $2 million just to keep the project functioning.
How It Works?
Right now, the GPS has a network of 31 satellites orbiting the Earth at a height of 20,000 km. No matter where you are on the Earth, at a given time at least 4 GPS satellites can be detected. Each of them relay information about their current location at regular interval of time. These signals are intercepted by your GPS handset and calculate the distance of each satellite by calculating how long the signal took to reach it.
Although, the GPS system can work more precisely with more satellites, it can still work with a minimum 3. Once your receiver has information on at-least three satellites, it can pinpoint your location with the help of a process known as trilateration.
Trilateration is a geometrical term, by which one can determine the relative or absolute positions of any given point. Suppose you are standing somewhere on Earth with at least three GPS satellites above you in the sky. Now, if by any means you find out the distance between you and the satellite A, then you can be sure that you are located somewhere in the circle A. If you repeat the procedure with two other satellites, B and C, you can actually pinpoint your location where those three circles intersect. That’s exactly how the system works.
GPS is Not the Only One
GPS is not only used by individuals but also by big MNCs and governments throughout the world. But there are several instances when the US government intentionally or accidentally disrupted the services. One such example of service interruption is during the kargil war in 1999, when Indian troops suffered heavily at the hands of Pakistani soldiers due to lack of indigenous positioning systems and service denial by the US government.
Several other incidents prompted many nations to develop their own similar networks. Russia was the first nation to develop a localized tracking and positioning system after the United States and now has a constellation of 24 satellites. Other Asian countries who are developing their full fledged positioning system is China and Japan. EU nations will also complete their network latest by 2020.
After the Kargil War incident, India has also made strides in this field. Currently, they have 6 working Geosynchronous satellites covering a majority of the Indian subcontinent for mainly military purposes. According to an estimation, the entire system will be operational by 2018.
While it has a reliability problem for other countries, most of them are still using GPS and doesn’t have any future plans to develop one of their own. The reason behind this can vary from lack of infrastructure, funds to lack of technological advancements. On the other hand, only Russia’s GLONASS constellation of satellites can actually compete with American GPS in terms of accuracy, while other systems are currently in an intense development mode.