what are the inputs of GPS
 

Morning, I came across this question the other day and I haven't a clue.

What are the inputs of a GPS?

I know that range is found by the timed travell of radio energy.

Ta

If that was an exam question I think I would play safe and say, "Satellite Signals". Anything else is an optional 'add-on', depending on where and for what the GPS is being used. Just MHO.

If anyone's interested in the really technical details of how GPS works, have a look here .

A few years ago I used to browse the physics newsgroups occasionally. There was a long-running flame war based on whether or not the GPS satellites' timing signals were adjusted for the relativistic effects resulting from their high speeds... there was a conspiracy-theorist claiming that GPS was a fiction and that man never really went to the moon, etc and so forth...

Off topic but interesting... hmm...

Regular inputs to a GPS receiver are time signals from the satellites. There is also reference or "ephemeris" data regarding the satellites' orbits that is updated occasionally.

The time signals are converted to position data by the computer in the GPS receiver.

Trimble have produced a nice simple description of how GPS works. The "clockerrors" section in particular is very interesting!

http://www.trimble.com/gps/how.html