We rely on GPS, or Global Positioning Systems, almost every day. We use it to navigate to a location we’ve never been before, find a highly-rated brunch spot near us, call an Uber or Lyft, track our kids and pets, and even continuously update the time on our cell phones. Eventually, it may even power driverless cars. For millennials and Gen Z, GPS technology has been available for most of, if not all of, their lives. I’m a 22-year-old college student, and I never had to learn how to use a physical map to drive anywhere unfamiliar like my parents did when they were my age; I always had a GPS available right in the palm of my hand.
Believe it or not, early forms of GPS technology were born in 1978, and have been developed since to provide us with resources like the on-demand directions on our phones and the magic behind our Scout Smart Trackers. This system cost around $12 billion to launch, and yet, it is free to users all over the world (Real Engineering, 2017). Have you ever stopped to wonder how all of this is possible? The Global Positioning System is made up of 31 satellites in space orbiting around Earth at an altitude of 20,000 km. At any given location on the planet, at least four GPS satellites are available for transmitting information about its current position and local time. When you use your GPS tracker, it intercepts these signals, which are traveling at the speed of light, and your device can determine how far the distance is to each satellite based on how long it took to receive the information. Once your GPS tracker is aware of where at least three satellites are, it can provide you with your exact location by relying on a system called trilateration (Physics.org).
Trilateration (Figure 1) is a mathematical technique used by GPS units to calculate your position, speed, and elevation. The information received from the first satellite only pinpoints a very broad location. A second satellite provides data that will narrow the location to reveal the region where the two spheres of satellite data intersect. Adding the third satellite’s data will provide a more specific location. Having four or more satellites will enhance the accuracy and help determine precise elevation (Zahradnik).
So how do our devices pick up the GPS signals? Our smartphones, Scout Smart Trackers, and other devices have GPS chips in them. This allows them to pinpoint their locations through GPS from anywhere in the world by using both the U.S. and Russian GPS systems.
The main functions that most people use GPS for are navigation, location, mapping, timing, and tracking. Because this technology has been readily available to us for at least a decade now, we don’t think twice about how convenient it is to know exactly where we are, where we need to go to get to our next location, and how long it’s going to take to get there. Thank goodness the days of poor passenger-seat navigators and ripped maps are over.