People use GPS extensively every day, but few people know how it actually works. How can a smartphone know where you are, so that you can use it as precise directions while driving?
Let's open the hood on the GPS and see how it works.
Let's say you're hiking in the woods when you get lost. That's fine, though:you had the smarts to download the official app for those woods. The app claims to help you find your way, wherever you are.
The app does this via five beacons installed around the forest:one in each corner and one smack in the middle. You use the app to ping one of the beacons and tell you how far away you are. Easy!
You decide to ping tower 2 in the hopes that it will prove more fruitful. Not at all, because it just says you are 3.2 km away. No direction either. Awesome. This too is just a useless circle.
But wait a moment; What if we combine the data obtained from tag 3 with that of tag 2? If we are 5.5 miles from beacon 3 and 3.2 miles from beacon 2, that puts us here:
It's much more useful! While the information from a single tag isn't very useful, we get more and more of an idea of where we are when we ping multiple tags. We can then collect the data from each beacon and find where we are.
As you might have guessed, the example above shows how GPS finds you. When you turn on GPS, your phone starts communicating with GPS satellites orbiting the Earth. Satellites can't tell you exactly where you are, but they can look at how long it takes to receive the request and calculate your location based on that.
As in the example above, a single satellite will give you a rough idea of where you are. Have you ever turned on GPS on a map and all you see is a huge circle around where you currently are? That's because your phone only talks to one satellite, which lets you guess roughly where you are.
Things get more refined as more satellites give their answers. Your phone then takes all the information from those satellites and finds where the ringtones meet. This is called “triangulation” and this is how GPS works!
We often use GPS to find our way, but it's not immediately obvious how it works. Now you know how satellites locate you and why it sometimes puts a very useless "you are here" circle over an entire city!
Was the GPS an accurate guide for you? Let us know below.
