How does a typical GPS system work?

Question

How do you select a location to travel to on a GPS system? Do you simply key in the destination and where you currently are and the system will go from there, or what?

Answer 1

Right (when speaking of automotive navigation). Put in the destination address, and the GPS unit's computer will estimate the starting address from your current position, then it will use its map database to calculate the route. As you go along, the GPS will announce upcoming turns, and if you deviate from the route it will try to get you back on track.

Answer 2

you key in your destination. the GPS contacts the satellite. the satellite knows where you are and maps out the route to the destination keeping track of you all of the way

Answer 3

the GPS system is a series of orbiting satellites. The receiver uses the data from the satellites to decode and determine you longitude, latitude, height above sea level, ground speed, as well as time of day and some other data.

it is up to the receiving device to decode the data string.

the fancy receivers have a built in mapset, graphical interface, audio interface and allows the user to access the mapset and lets the receiver speak directions as well as display a moving map on the GUI.

Answer 4

Actually you don't have to put anything in to the GPS system if it is really GPS it automaticaly keep track of the gps transmitter

but if you want direction to a place thats a another story ;)

Answer 5

Murzy,

The GPS DOES NOT contact the satellites and the satellites have no idea where you are!  

Please, limit your responses to things you are knowledgable about.  Do not make stuff up.  As the old saying goes, It is better to remain quiet and be thought a fool, than to open your mouth and remove all doubt.

GPS is a passive technology that acts very much like a radio receiver.  The satellites broadcast radio signals that carry a code along them (the PRN).  The GPS receiver counts how many times that code was broadcast from when the signal left the sat until it reached the receiver.  By doing this it can determine how long it took the signal to reach the receiver and therefore how far the receiver is from the satellite.  The receiver determines its location by doing this for a number of satellites.  It is called trilateration.

John D,

Since the GPS constantly keeps track of your position as I described above, all you need to do is use its interface to enter your destination.  The software then determines a route for you to follow.  Many devices allow you to select whether you want the fastest route, fewest turns, or cheapest (avoiding tolls whenever possible).

I hope this answers your question.  If you have any further questions feel free to contact me.  I am a GPS professional with years of experience with professional grade equipment.

Answer 6

John

I can go into detail as to how a GPS system function but I can't do as nice a job as Garmin academy has.

It is a fun video that you can watch and learn the basics about GPS functionality.

http://www8.garmin.com/gpsacademy/

Hope this helped