We all know that our GPS devices work with the help of satellites that orbit the earth, but the technology is far more complex than that. Unless we know exactly where the satellites are, we can’t get an accurate location reading from them. A new effort from NASA aims to coordinate the four different geolocation systems in a single station to achieve more accurate, consistent readings than ever before.
Tracking GPS satellites is a fascinating, complex process that combines state-of-the-art technology with mathematical techniques that are centuries old. In fact, ancient Greeks were able to use these techniques to figure out almost exactly how far the distance is around the planet. At its core, judging the location of satellites in relation to the earth’s surface is geometry, using angles and side lengths of triangles to find out where a satellite is. Of course, there are complicating factors, like the fact that each satellite is constantly in motion.
The earth itself is not even consistent in its position and stability. Any number of influences change the way satellites and signal receivers relate. Earthquakes and continental drift, for example, are constantly shifting the objective location of earth-based sensors. With the huge distances that are involved, even a very slight dislocation can throw off the accuracy of GPS readings submitted by the equipment. NASA’s plan hopes to minimize these effects by creating a single central location for tracking GPS satellites of multiple types. Instead of coordinating readings across the globe, the four primary geolocation systems could work together closely to maximize accuracy.
For the average private user of GPS technology, absolutely perfect accuracy is not a priority. If you are using your smartphone, for example, to find out what restaurants are in your area, you don’t care whether your location is off by ten feet. But many of the original purposes of GPS are far more critical and depend on pinpoint precision. Artillery strikes and military rescues under fire are an obvious example. Tracking GPS satellites isn’t just an exercise to find out how accurate we can get; it is an effort to save lives and make the world a safer place.Google+