How does a Smartphone know your exact location?
Have you ever found yourself in a situation where you are stuck at a place, unsure of where to go next? This can be very frustrating, especially if you are new to that place. If you are like most people, you probably look for places on your smartphone, navigate towards it and end up getting there without any issues. This is exactly what Google Maps does. With this handy application, you can navigate towards any destination easily and fast with no fuss.
Let us understand how this technology works.
Your Smartphone uses Global Positioning Satellites (GPS) that allow it to gather accurate information about your exact location - so that there's never a wasted trip!
But, how does the Smartphone know your exact location?
The answer lies in outer space, some 12 000 miles above your head in an orbiting satellite powered by Quantum physics! Let's break down the concept into earthbound terms.
Your cell phone needs to know how far it is from the satellite. Each satellite in space broadcasts
radio signals that travel from space to your phone at nearly 299,792, 458
meters per second (speed of light).
Then your phone records the signal arrival time and uses it to calculate the distance to the satellite with the help of a simple formula:
Distance = Speed of light x Signal arrival time.
To accurately calculate the distance of your device from the satellite, atomic clocks are utilized in satellites. These clocks work on the principles of quantum mechanics and as a result, are a lot more precise than conventional clocks. They can give a time reading accurate to within 1 billionth of a second!
We now know that you are at a fixed distance from the satellite. In other words, you are somewhere on the surface of a sphere centered around this satellite. By measuring your distance from another satellite with the same procedure, we get two overlapping spheres. With at least three such overlapping spheres centered around three different satellites in space, your exact location on the sphere (earth) gets pinpointed.
And surprisingly, all this is accomplished within 2-4 seconds! Now, how cool is that?