[time-nuts] Satellite Glitch Rekindles GPS Concerns
xde-l2g3 at myamail.com
Thu Jun 18 13:40:43 EDT 2009
> Hi Mike:
> The current issue of Inside GNSS has two articles about this and
> their web page has a new article dated 17 June 2009.
> Hi again Mike:
> The IIR-2 satellite was launched in order to meet a deadline
> rather than when it was truly fully operational. The L5 module is
> an add on and can not run at full power. So this is not a
> representative of the future sats.
> Have Fun,
> Brooke Clarke
Running at full power would make the problem worse, don't you think?
This slipped past all the modeling and simulations prior to launch,
so as well as fixing the problem, they also have to improve the
simulations. Somehow that doesn't seem like such a difficult
Overall, I think they did a pretty good job for such a complex
system with such incredibly tight performance parameters.
At least it still works, with degraded accuracy. And it looks like
they can fix it. So it's not like sending a billion-dollar satellite
to Mars and having it crash because someone forgot to convert
between US and metric values:)
Hopefully the L5 addition will help reduce the diurnal variation in
ionosphere delays that affect the accuracy of the timing signals. So
progess in this area is of interest to us.
And thanks for the link to insidegnss. That looks like an excellent
resource for updates on the technology.
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