For a world with 32 operational GPS satellites

So far USAF haven't said a word as far as what PRN will be used for
the next GPS satellite. We're about two months from the planned launch
date.
My opinion is re-use PRN1, and put SVN49 into residual mode for a
while.
Leave SVN49 residual until 2015, considering a single IIF launch per
year.
PRN1 isn't contributing at all to the GPS constellation with an
unhealthy signal, while all other satellites are.
At the same time I read somewhere on the internet that USAF's own GPS
augmentation network can't augment PRN32, this would be another reason
to put SVN49 aside for a while, when SVN49 is reactivated, it could
use PRN32. Wait until there sixth IIF satellite gets launched, by then
there will be 24 modernized (IIR/IIRM/IIF) healthy satellites plus
SVN49. That would mean that IIA satellites are completely not
essential anymore.
On all articles explaining the gained experience from GPS satellite
longevity, we get the sense that IIR satellites will last quite a bit
more than the IIA birds.
And if IIA satellites start failing on mass, SVN49 can be reactivated
into a degraded but healthy status if an actual pressing need arises.
Until then all GPS manufacturers wishing to test SVN49 signal can use
a GPS signal recorder available for a while now. SVN49 doesn't need to
broadcast a live signal for manufacturers and researchers to test with
their signal.

Regards,

Marcelo Pacheco

The last Delta IV left the Cape with NROL-27 on 11 March clearing the
pad for a GPS IIF launch during late June. Assembling a Delta IV
launcher a processing a satellite has historically required about
three months.

The problem is, that's only two months from now and I haven't seen any
news about the satellite being transported to the launch site. With a
GPS community closely following constellation modernization, any
positive scheduling activity is 'big news' worthy of a press release.

There has been no recent news concerning the readiness of the next
satellite; let alone its position in the constellation or PRN.
Perhaps they are fixing the L5 signal generator removing the phase and
signal distortions identified by the international GNSS community.
Perhaps they are working towards reducing thermal effects upon the
atomic frequency standard.

--- CHAS

So, there might be a delay in the launch of IIF-2.
My point was if it gets launched, please use PRN1 for that.
Thats regardless of the issues raised, which are important to know
anyways.
Thanks CHAS.

a

Guess what? I just came upon this announcement from the USAF:

4/20/2011 - LOS ANGELES AIR FORCE BASE, Calif. -- Officials from Air
Force Space Command's Space and Missile Systems Center announced the
delivery of the second in the series of twelve GPS IIF space vehicles
to Cape Canaveral Air Force Station, Fla., April 20. GPS IIF SV-2 is
expected to be launched aboard a United Launch Alliance Delta IV
rocket later this summer. ...

A June or early July blast off is possible if satellite and launcher
processing goes well.

I'm guessing the system operators will remove a Block IIA satellite
from service before this one goes up. For whatever reason, they don't
seem to be ready for 32 satellites.

--- CHAS

y
h a
d

Is there such a thing as too many satellites?

If there are a lot of other satellites, doesn't that reduce the
visibility of the sighal when the receiver achieves frequency and
phase lock with the satellite being looked for?

Assuming that half the satellites are above the horizon, the nominal
configuration would have a receiver picking out one SV againt 11
broadcasting "noise". With 32 active, this changes to one SV agains 15
noise sources.

Or have I totally misunderstood how this thing works...