Tech corner: understand GPS and how it works

What does GPS stand for?

Stumped?

Maybe we don’t all have such a great idea of what GPS (Global Positing System) is.

Yeah, it helps us avoid traffic, find restaurants and, in ExakTime’s case, track crews. GPS speaks to us – sometimes literally.

But odds are you don’t really, really know what it is.

Read on to impress your coworkers at your next coffee break.

GPS – Satellites

The simple explanation behind GPS is this: If you know how far away you are from three known points, you can use high school math to determine exactly where you are. GPS uses satellites to create those points.

A GPS receiver compares signals from at least three or four GPS satellites (minimum) to determine its location. There are at least 24 operational GPS satellites at all times. GPS receivers require an unobstructed view of the sky.

The GPS receiver estimates how far away a satellite is and compares that measurement to the distance of the other satellites.

The accuracy of a position determined with GPS depends on the type of receiver. Most handheld GPS units have about 10-20 meter (30-60 feet) accuracy.

Assisted GPS – Satellites and Cellular

Assisted GPS (also known as A-GPS or AGPS) is used extensively with cellular phones and is described as a system that uses a cellular network to improve the performance of GPS receivers. It also helps improve the location performance of cell phones.

WPS – Wi-Fi/ Cellular/Satellite

Wi-Fi Positioning System (WPS) is another type of positioning system that maintains a large global database of Wi-Fi IP addresses and their locations. This data may then be used by a mobile electronic device to triangulate a user’s position.

This system is used primarily by Apple products, but some Androids use it as well.

Limitations: WPS does not work when out of range of Wi-Fi signals, and the Wi-Fi hotspots database must be constantly updated to keep up with Wi-Fi hotspot changes. It also only works when you are connected to a WIFI hotspot. So if you are within range of a hotspot and you are NOT connected to it, it will NOT be possible to use the hotspot to triangulate your position.