thoughts on A-GPS offline

[Helge Hafting]

Timo Juhani Lindfors wrote:
> mqy <meng.qingyou at gmail.com> writes:
>> It is not a problem that user account is required when download u-blox online
>> aiding data.
> 
> It is a problem since u-blox might go out of business and you might
> not want to tell them where you are all time. Their server also might
> be down. There are plenty of reasons to remove dependency to any
> single party.

It is possible to start an open service, with mirrors. Interested people 
can set their freerunners to send in good aiding data when they have it 
(i.e. when using the gps and a network is available.)

Such a update gives away where you are, because the satellite 
constellation is only seen from part of the world. But I believe this 
part is large enough for privacy.

People using the service don't need to give away much. In an extreme 
case they will download ephemeris data for _all_ satellites, and then do 
the processing based on approximate location in the phone itself.


Helge Hafting