Congratulations to the 2nd SOPS in reaching the current maximum number
of healthy GPS birds, 31.
If they only could have kept PRN30 a bit more half way (farther away
from its pair), maximum PDOPs would be at least 1 meter lower.

Marcelo

On Dec 19, 8:00*am, macpacheco <marc...@macp.eti.br> wrote:
> Congratulations to the 2nd SOPS in reaching the current maximum number
> of healthy GPS birds, 31.
> If they only could have kept PRN30 a bit more half way (farther away
> from its pair), maximum PDOPs would be at least 1 meter lower.
>
> Marcelo

They do fantastic work maintaining high level service with aging
equipment but they really do need to strengthen the A Plane with a new
satellite. That will probably happen sometime around 26 September
2012 when GPS IIF-3 is tentatively scheduled to leave atop a Delta IV
rocket.

Let's hope they get the atomic clocks working better. The signal in
space performance of GPS IIF-2 is still inferior to GPS IIF-1. I'm
generally not all that thrilled about the IIF satellites but they will
probably do OK bridging the gap until Block III satellites are
ready. The Air Force says they meet specifications.

But Galileo, with its hydrogen maser clocks, will raise the bar for
clock performance. That might not be significant for general
navigation but GNSS civil applications have be trending more towards
ultra precision applications. It's been said the redesigned Perkin
Elmer rubidium clock can perform nearly as well but flaws in its
performance have been documented. Some analysts believe there are
thermal effects in play.

Hopefully the Block III spacecraft buss can maintain a more constant
temperature profile if that is the case.

--- CHAS

On Dec 19, 4:35*pm, HIPAR <captc...@verizon.net> wrote:
> On Dec 19, 8:00*am, macpacheco <marc...@macp.eti.br> wrote:
>
> > Congratulations to the 2nd SOPS in reaching the current maximum number
> > of healthy GPS birds, 31.
> > If they only could have kept PRN30 a bit more half way (farther away
> > from its pair), maximum PDOPs would be at least 1 meter lower.
>
> > Marcelo
>
> They do fantastic work maintaining high level service with aging
> equipment but they really do need to strengthen the A Plane with a new
> satellite. *That will probably happen sometime around 26 September
> 2012 when GPS IIF-3 is tentatively scheduled to leave atop a Delta IV
> rocket.
>
> Let's hope they get the atomic clocks working better. *The signal in
> space performance of GPS IIF-2 is still inferior to GPS IIF-1. *I'm
> generally not all that thrilled about the IIF satellites but they will
> probably do OK bridging the gap until Block III satellites are
> ready. * The Air Force says they meet specifications.
>
> But Galileo, with its hydrogen maser clocks, will raise the bar for
> clock performance. *That might not be significant for general
> navigation but GNSS civil applications have be trending more towards
> ultra precision applications. *It's been said the redesigned Perkin
> Elmer rubidium clock can perform nearly as well but flaws in its
> performance have been documented. *Some analysts believe there are
> thermal effects in play.
>
> Hopefully the Block III spacecraft buss can maintain a more constant
> temperature profile if that is the case.
>
> --- *CHAS

I just hope one IIF satellite actually makes it to the best
performance of all GPS birds. I understand there's this huge
performance difference between orbits, some are much more active in
solar winds / thermal cycles / solar eclipses, other are quieter,
IIF-1 was launched right into the most rigorous orbit (the orbit where
GPS birds last the least), and it isn't performing so bad considering
that. Hopefully the A plane is a quieter one that will allow for the
IIF to show what performance it can deliver. High hopes for IIF-3.

Marcelo Pacheco

On Dec 20, 1:28*am, macpacheco <marc...@macp.eti.br> wrote:

> I just hope one IIF satellite actually makes it to the best
> performance of all GPS birds. I understand there's this huge
> performance difference between orbits, some are much more active in
> solar winds / thermal cycles / solar eclipses, other are quieter,
> IIF-1 was launched right into the most rigorous orbit (the orbit where
> GPS birds last the least), and it isn't performing so bad considering
> that. Hopefully the A plane is a quieter one that will allow for the
> IIF to show what performance it can deliver. High hopes for IIF-3.
>
> Marcelo Pacheco

That's an interesting statement. I never thought about it but, if one
examines the variables, there is a case for the six orbital planes not
being exactly identical in the space environment.

--- CHAS