GPS

GPS (Global Positioning System) is a complicated web of technology that has commonly and easily been taken for granted. Most of us even reference the system incorrectly. When we say "GPS," we're actually referring to the GPS receiver which, as the name suggests, receives input from a system of satellites in space (the actual GPS) to compute your location.

The GPS receiver primarily works by using 3-D trilateration.  In simplified terms, the receiver on Earth receives transmission from the different satellites in space and  relates them to its/your location. The transmission that the satellites give off is a "long, digital pattern called pseudo-random code." The receiver can determine location because the transmission is interrupted when it comes into contact with the receiver. The amount of time that the transmission is interrupted corresponds to the amount of distance between the satellite and the receiver which gives the receiver a reference point to work with. Once the receiver has received enough information from multiple satellites, it can calculate and output your location and provide a path to your desired location by continuously collecting information from satellites as it moves. In order to improve accuracy, the receiver stores the memory of each satellites' location as well as map detailed files in its software. Based on this explanation, you can easily see that GPS is a great example of a common, household tool that works because of algorithms and computer science.

References:

http://www.academia.edu/7304657/A_Review_on_GPS_and_its_Applications_in_Computer_Science_

http://electronics.howstuffworks.com/gadgets/travel/gps5.htm

http://www.figonet.com/en/building-blocks/sensors/gps/

http://sonc.dvrlists.com/gps/