[FOSS-GPS] GPS in space?

[Abdelrazak Younes]

On 05/11/2008 17:56, Risto H. Kurppa wrote:
> Hi!
>
> Does anyone know how well GPS works in the space?

Better than down there :-)

>   How high is it still
> reliable, what causes the possible errors and so on?

The higher you go the less atmospheric (tropo and then iono) error. Of 
course the navigation software has to be modified to take this into 
account. In space GPS navigation is already used for going to the ISS 
for example.

>   If you take a GPS
> device beyond the geostationary level (where the satellites are?),
>    

Not really, GPS have a 20000 km orbits whiles Geos are at 36000 km.

> what happens?
GPS diffusion is only downward the earth so it you are above the GPS 
orbit, the only solution would be to use GPS satellites that are on the 
other side of the earth but still visible. Of course sometimes this 
would mean a higher atmospheric error because the signal would go 
through it twice.

>   I suppose some customization is required but a normal
> handheld GPS wouldn't handle it properly.
>    

Yep.

Abdel.