Although the Global Positioning System (GPS) developed by the United States Department of Defense was initially restricted to military use such as army navigation, target location determination, minesweeping and aircraft operations-making it an indispensable aid for nearly all military operations and weapons systems-today it also used for civilian purposes in many aspects of day-to-day life, from medicine to environmental science.
The system provides highly accurate and free location and time information to anyone equipped with a GPS receiver. The system provides a precise, common location and time reference in all weather conditions, anywhere in the world. The system consists of satellites that are fitted with atomic clocks and continuously revolve around the earth. These satellites are placed into the orbit in such a way that at any time, any where, a GPS receptor on the earth receives signals from at least four satellites. In a nutshell, global positioning works with low frequency radio signals that transfer coded information from satellites to receivers. Received information is used to calculate the distance between the receiver and the satellite, which is used to define the location of the point on the earth within the defined coordinate system.
One of the most practical examples of the non-military use of GPS is the Paris city bus network. In Paris, all buses are observed from the control center and time of arrival of any bus to the stop can be monitored on panels at the stops. Other examples of where the technology is put to innovative and possibly life-saving use include the Vehicle Surveillance Systems, where GPS is used in quickly locating ambulances, police, fire fighters, and taxis to dispatch for emergencies with the help of digital maps which identify the most suitable vehicle within the closes range to the site. A relatively recent invention introduced by a British firm is a parent-friendly child wristwatch with an improved built-in global positioning system. The easy-access navigation systems in car and cell phones have certainly made life a little simpler for many consumers.
GPS has also be utilized to track environmental issues like the observation of earthquakes, volcanic eruptions, tidal waves and enabled ways to take some necessary precautions against natural disasters. In short, GPS has multiple uses on land, air and sea. Lately, scientists are increasingly pointing to the role of GPS in tracking climate change, watching indicators of environmental degradation such as greenhouse gases, melting of glaciers, and sea levels, providing reliable and fast data. Today, scientists can use GPS to gather data on tidal waves in order to investigate sea level changes that are connected to global warming at close proximities to coastlines; monitor holes in the ozone layer over the polar region thanks to GPS-equipped balloons; measure air quality; and guide cleanup operations after major oil spills. When GPS receivers are positioned at mountain tops and buildings, scientists can measure changes in sea level from a range of 20 km; allowing for the collection of possibly breakthrough data. Keeping in mind that scientists warn that 100 years from now, there won't be an Antarctica to speak of, these findings become all the more valuable.
Global monitoring conducted by the EU-funded European Space Agency (ESA), records and interprets environmental degradation from damages caused by forest fires and the loss of available agricultural land with the help of GPS. With information gathered from satellite computers with highly sensitive equipment, it is possible to draw-up alternative global warming scenarios.
According to British meteorologists, GPS can be used as a global thermometer for monitoring climate change. With the technique of "GPS radio occultation", first applied in 1995, atmospheric measurements like temperature, water vapor levels, and density of air can be taken with accuracy. The system involves low-orbit satellites receiving signals from GPS satellites. The signal has to pass through the atmosphere and gets refracted along the way. The magnitude of the refraction enables atmospheric measurements. According to the statements of scientists, level of global warming can be understood with the help of data gathered by this technique.
Competing Systems: Europe's Galileo and Russian GLONASS
Part of the reason behind global competition to break the U.S. monopoly on GPS technology is the many uses for GPS beyond its traditional functions, as well as economic profit in a growing market, that the technology promises. What did other global powers do while the U.S. was building and installing such an effective system? Concerned about the U.S. monopoly on GPS satellite navigation, Russia, the European Union and China initiated development projects for their own competing systems. During his presidency Vladimir Putin had pressed the country's scientists to make the Russian system better and cheaper. The case for strategic imperatives is also clear. In case of a dispute or armed conflict, the U.S. can easily cause a black-out or deny access of other powers to GPS, leaving soldiers at the target region possibly stranded. Although the system provides enough bandwidth, the risks involved in depending on a U.S.-infrastructure in the event of armed conflict triggered states to build their own system.
The cost of developing and installing such a system for use in various different applications was certainly not a cheap investment for the U.S. However, we should not forget that the U.S. retains full control over this precise system, built originally for its own military purposes, before opening it to civilian and commercial use. This essentially means that every satellite in the system has encryption equipment, which can only be decrypted by the U.S. As a result, civilian use of GPS was limited to how much the U.S. would allow. U.S. National Security officials opposed the end of encryption on the grounds that this would negatively affect national security and possibly benefit terrorist activity. In the end, encryption was ended after intense public pressure. The early American GPS system was programmed to generate what was essentially false data by the receiver. Called ‘Selective Availability' the error was programmed into satellites so that the GPS would bring up random errors of up to 100 meters, a function designed to keep GPS an exclusive and powerful tool for the military. Selective availability was turned off in 2000, but the feature still exists and the risk that it can be re-enabled remains.
The European Union and ESA's alternative to the U.S. military controlled GPS is Galileo, although it is not as far along as Russian GLONASS. Projected to consist of 30 satellites, Galileo promises to provide more precise coordinate information than GPS and the system would be up and running during wartime. Expected to be completed by 2010, the first satellite was sent into orbit in 2005. The primary reasons for developing Galileo are 1) The precision of existing GPS is unable to meet the standards required for civilian airlines; 2) Detecting possible malfunctions in the GPS satellites and transmitting this information to users; and 3) The potential risks inherent in a one one-state domination of GPS technology. GALILEO will at the same time be interoperable with GPS and GLONASS, the two other global satellite navigation systems.
The world media was surprised when Russia launched three new satellites into orbit in 2007. With this development, GLONASS (Global Navigatsionnaya Sputnikovaya Sistema) operated by the Russian Space Forces became GPS's main competition. In a bid to cut-back on the dependency on U.S.-based GPS devices, Russia is hoping to go global with GLONASS sometime in 2009. The motivation is mostly driven by the will to produce an effective alternative to American technology. The USSR had launched the first GLONASS satellite back in 1980. Despite Russian efforts to develop the program throughout the 1980s, the U.S. was also simultaneously working on its global positioning system and launched the first satellite as early as 1978. The development of GLONASS ground to a halt during the dissolution of the Soviet Union and the economic turmoil that would follow. Although the system had the necessary 24 satellites in orbit, it was undercut by financial setbacks and never became operational. Seen as part of Moscow's plans to boost hi-tech sectors of the Russian economy, the program received much-needed funding in Putin's Russia with the approval of a federal program in 2001. Although it became operational at nearly the same time as GPS, and has considerable capacity it has not yet caught up with GPS. But despite early setbacks, GLONASS's coverage has reached 90% over Russia and 80% over the globe with the recent developments.
Although, today Russia cannot compete with the U.S. in space exploration technologies; that it had surprised everyone when it launched its first satellite in 1957 is worth remembering. However, Russia is not looking to get caught up in another space race with the U.S. Russia's priority these days is to assume the status of sole power in a strategic region that is increasingly beyond the U.S. "coverage area." This is precisely what GLONASS hopes to accomplish. According to projections made by Russian officials in October 2008, GLONASS aims to be available worldwide by the end of 2009, for which it would need to have 24 satellites.
The United States and Russia initiated cooperation in 2004, with the primary goal of enabling civil interoperability at the user level between GPS and Russia's GLONASS system. Two working groups have been established to address some key issues since then, and a joint statement was made by Washington and Moscow back in 2006 stating progress had been made on understanding the benefit to the user community of changing GLONASS to a signal pattern that is in common with GPS and Galileo.
In short, historical breakthroughs in technology in civilian and military fields, as much as they advance the common aspirations of mankind, are also closely linked to geopolitical maneuvering and interests. Unless Galileo and GLONASS become fully operational, the only global positioning system will remain under the control of the U.S., which means that strides in strategic technology is also part and parcel of global political positioning.

Geodesy and Photogrammetry Engineer