Question A free GPS which also works in deep space?

[Topper]

Hello,

i was wondering, how they navigate probes in deep space .
Searching for an answer, i've found this article here.

They said, they can use pulsars with known and exact period to calculate the position in deep space. If they have maybe 4 pulsars with exact periods, it's possible to calculate the position by the time difference of the signals to a theoretic calculated reference signal.

(I think you have to know your estimated position because if not, the signals can be lapped)...

For spaceprobes, this will work with a precission of "a few kilometers".

I know this is not the technology of today.
Does it will it be possible to get the position also on earth surface by this method, so GPS is not longer required?
I don't know how complicate it is to build a signal reciever for such signals, but i think this could be a problem...

And you also need a good database for the reciever with vectors of the pulsars, exact period etc...

 

[Piper]

Theoretically I think you can do it. You would of course need telescopes and some pretty good computers to do it. With that said, if you are going to be looking at the stars to determine your position on the Earth, there are far simpler ways to do it. Namely, you can just use an Astrolabe.

 

[Topper]

But it's not easy to automate the position computation using an astrolabe. You need always a clear sky for example... :lol:

You also need some good computers for GPS today, but maybe for this case, they have to be much more good and i think they need also to have their own exact chronometer, because in GPS technology, the time is send with the signal (the clock is in the GPS satellite). I think the "computer problem" can be solved in future (I don't know if it's already possible with the capability of a Smart Phone today).

The signal of a pulsar don't have a time in the signal, so the reciever has to have it's own "atomic clock"....

Maybe this is also a problem...

 

[Arrowstar]

Interplanetary orbit determination is typically done with with laser or EM radiation of some kind, though I suppose optical navigation is also coming along fairly well. I'm not much of an expert, though, so feel free to correct me.