thoughts on A-GPS offline

Raphaël Jacquot sxpert at
Sun Mar 1 22:00:22 CET 2009

On Sun, Mar 01, 2009 at 12:57:30PM -0800, mqy wrote:
> U-blox receiver allows polling AID-EPH, AID-ALM data.
> For each type, we can poll 32 messages for 32 satellites. 
> The precondition is: current fix is valid -- at least 3 SVs has valid EPH(or
> ALM?) data.
> These data get invalid 2~4 hours later, 
> can be stored into files, and load into GPS receiver when needed and they
> are valid.

they can probably still be used to get a rough estimate

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