GPS - An Important Technology to U.S. Troops

The GPS Provides Critical Information In Combat Zones

GPS Satellites
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To say the satellites that make up the Global Positioning System's constellation is a revolutionary invention is the understatement of the 21st century.  With its navigation and image capabilities, Global Positioning Systems (GPS) have become one of the most important technologies to the U.S. military since its development in the mid-1900’s.  It has become such an integral part of our lives and the military that it now has its own government website for personal and commercial users. The GPS is a prime example of technology that has gone from tactical to practical.

History of the GPS: Helping Soldiers Navigate

Known by its initials "GPS," the Global Positioning System has only been commercially available since 1994. And the U.S. space-based global navigation satellite system is best known for helping civilian drivers navigate their way through suburban streets on our smartphones and car-based systems.

But the technology – which provides reliable navigation services and detailed images anywhere on earth – has proved to be an invaluable tool to the U.S. military and other defense forces around the world since the 1980's.

With the ability to provide accurate positioning continuously, day or night, in any conditions, GPS has helped ground troops in Iraq and Afghanistan navigate across expansive, barren deserts that have few markers or distinguishable features. They have also proved reliable in sandstorms when visibility is reduced. The GPS device also enables the U.S. military and its allies to distinguish friendly soldiers from enemy troops – reducing incidents of friendly fire in combat zones.

How the Satellite Constellation Works

The Global Positioning System – also known as NavStar circle the earth twice a day. If you have a GPS receiver on the ground, the GPS receiver takes this information and uses 3-4 satellites to triangulate the user's exact location. It is basic time, distance, speed, direction math of the satellites to the receivers used to locate how far the receiver is from the positioning satellites.  The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's map.

A GPS receiver must be locked on to the signal of at least 3 satellites to calculate a latitude and longitude and track movement. With four or more satellites in view, the receiver can determine the user's 3-D position (latitude, longitude, and altitude). The GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.

Wide Application

The devices are in place on planes, helicopters, jets, naval warships, ground vehicles as well as the individual troops.  The North Atlantic Treaty Organization (NATO) has made GPS devices standard for use by its member nations.

The detailed satellite images provided by GPS are also critically important to military intelligence. Soldiers working in intelligence rely on GPS for information that allows them to make operational and tactical decisions in real time.

Future Uses for the Device

As of September 1, 2016, there were 31 operational satellites in the GPS constellation. It does not include the decommissioned GPS satellites kept in orbit in case there is a need to reactivate them. The operational satellite count is broken down by 12 satellites launched in 1997-2004, 7 launched in 2004 -2009, and 12 launched in 2010-2016 for a total of 31 operational satellites making up the current constellation of satellites that make all GPS systems operate.  There were plans for another dozen satellites to arrive in orbit in 2016 -2017 to replace aging satellites which have been operating beyond their projected lifespan.

For more up-to-date constellation status information, visit the NAVCEN website operated by the Coast Guard.

Military units around the world are looking at new uses for GPS. The devices are being added to weapons and firearms, and some countries – such as the Israeli Army – are exploring the possibility of embedding GPS devices into soldiers vests and uniforms so that field commanders can track their soldiers’ movements in real time. The Israeli government has stated that embedding GPS devices in soldiers uniforms would also help reduce incidents of friendly fire.