The Relationship Between Satellites and GPS and
How they Work Together:
Abbey Park High School
RELATIONSHIP BETWEEN SATELLITES AND GPS
The GPS System
When it comes to traveling, a GPS (Global Positioning System) is a very useful tool to have for saving a good deal of time and gas. However to understand how they work, we have to look at the satellites that are constantly orbiting around our planet in order to let the GPS do its job. Those satellites play a very crucial part for GPS receivers and are responsible for finding your exact location on earth.
To send a satellite into space, they are placed into a “launch vehicle”, which are very powerful rockets that carry the satellite out of the earth’s atmosphere. Once it has escaped the atmosphere the satellite separates itself from the vehicle and is sent into a transfer orbit, which positions the satellite further away into its arranged orbit. They then open solar panels and communication antennas to contact with the people down below (FCC Satellite Learning Center, n.d.).
In total there are a constellation of over 24 GPS satellites orbiting around the earth at an altitude of 20,000 km from the ground with an orbital speed of about 14,000 km/h. The satellites are solar-powered and make two revolutions of earth per day (orbital period of 12 hours). Their orbital paths are arranged so that at least four satellites are visible to the GPS receiver at any given point and time on earth to transfer data. The satellites all carry an atomic clock (valued around $100,000), which ticks with an accuracy of one nanosecond and sends out periodic signals along with a time signal at the speed of light to the GPS receiver below. The receiver obtains the time signals and compares it with a number of satellites to determine your current position and distance on the planet. This process is called trilateration and this system basically
References: Fischetti, M. (2008). Where on Earth You Are. Scientific American, 299(6), 116. Griffin, D. (2011). How does the Global Positioning System work? PocketGPSWorld.com. Retrieved October 28, 2014, from http://www.pocketgpsworld.com/howgpsworks.php How Do Satellites Get Into Space? (n.d.). FCC Satellite Learning Center. Retrieved October 28, 2014, from http://transition.fcc.gov/cgb/kidszone/satellite/kidz/into_space.html How does GPS work? (n.d.). physics.org. Retrieved October 25, 2014, from http://www.physics.org/article-questions.asp?id=55 Leick, A. (2005). How do GPS devices work? Scientific American. Retrieved October 29, 2014, from http://www.scientificamerican.com/article/how-do-gps-devices-work/ Ridenour, B. (2009). How has GPS Changed our Lives. Inside Technology. Retrieved October 23, 2014, from http://www.insidetechnology360.com/index.php/how-has-gps-changed-our-lives-25758/ The Impact of GPS Systems On Daily Life. (n.d.). The Centre of Technology. Retrieved October 23, 2014, from http://www.centertech.org/the-impact-of-gps-systems-on-daily-life.php