In this month’s Unveiling the Everyday, we are going to look at how our phone’s GPS works to get us from point A to point B virtually anywhere in the world. Before smartphones and GPS and internet driving directions, people relied on foldable paper maps to navigate unfamiliar territory. As a child growing up in the 1960’s and 1970’s, I remember my parents driving down the highway with a giant paper map covering most of the front seat. My mom would trace our path with her finger and give my dad directions on where to turn and what exit to take. She basically played the role of Siri, except she could not warn us about accidents or speed traps that awaited us down the road. We relied on the CB radio for that. 

Maps of course are now obsolete. They were initially replaced by internet driving directions and now most everyone relies on the GPS on their phone to get directions. But how does this miraculous technology work?

At the core of GPS are over 25 satellites orbiting the Earth, continuously sending signals to the ground. When your phone receives these signals, it calculates how far away each satellite is based on the time it took for the signal to travel. This is known as trilateration.

Your smartphone needs signals from at least four satellites to determine your exact location. With three satellites, your phone can pinpoint your position in two dimensions – latitude and longitude. But to pinpoint your altitude (how high you are above sea level), your phone needs a fourth satellite’s signal.

Once your phone calculates your location, it cross-references it with detailed maps stored in the phone’s software, allowing it to figure out the best route to your destination. It’s not just about knowing where you are. Your phone also uses sensors like the compass, accelerometer, and gyroscope to fine-tune its directions. The compass of course determines the direction the phone is facing. The accelerometer measures acceleration and changes in speed to help track movement. The gyroscope detects the phone’s rotational movement to provide precise orientation information.

Your phone’s GPS system uses a combination of user reports, traffic sensors, and GPS data from millions of other devices to warn you about traffic jams, road closures, accidents and slowdowns. For example, if many users are moving slowly on a particular route, the app can detect traffic jams and adjust your route accordingly.

GPS technology has undeniably transformed the way we navigate the world, offering unparalleled convenience, efficiency, and accuracy. With the ability to avoid traffic jams, road closures, and accidents, it has made travel easier and safer. However, this convenience has come at a cost. Many of us, including myself, have become so reliant on GPS that we’ve lost the ability to navigate even familiar routes without its assistance. While GPS has revolutionized our daily lives, it has also reshaped our relationship with direction and memory, making us less confident in our own spatial awareness. Nevertheless, I’ll take a little loss of spatial awareness and a shrinking hippocampus to have the benefits that GPS technology offers.