PRN30 has been removed from the broadcast almanac.
PRN01 has been included in the almanac:

******** Week 621 almanac for PRN-01 ********
ID: 01
Health: 063
Eccentricity: 0.2546310425E-003
Time of Applicability(s): 589824.0000
Orbital Inclination(rad): 0.9600353241
Rate of Right Ascen(r/s): -0.7490598364E-008
SQRT(A) (m 1/2): 5180.309570
Right Ascen at Week(rad): -0.1884143710E+001
Argument of Perigee(rad): 2.479846239
Mean Anom(rad): 0.1795769095E+001
Af0(s): -0.9536743164E-005
Af1(s/s): 0.0000000000E+000
week: 621


--- CHAS

On 2011-07-21 11:11 , HIPAR wrote:
> PRN30 has been removed from the broadcast almanac.
> PRN01 has been included in the almanac:
>
> ******** Week 621 almanac for PRN-01 ********
> ID: 01
> Health: 063
> Eccentricity: 0.2546310425E-003
> Time of Applicability(s): 589824.0000
> Orbital Inclination(rad): 0.9600353241
> Rate of Right Ascen(r/s): -0.7490598364E-008
> SQRT(A) (m 1/2): 5180.309570
> Right Ascen at Week(rad): -0.1884143710E+001
> Argument of Perigee(rad): 2.479846239
> Mean Anom(rad): 0.1795769095E+001
> Af0(s): -0.9536743164E-005
> Af1(s/s): 0.0000000000E+000
> week: 621
>
>
> --- CHAS

Do you know which vehicle (model, #) this is?

--
gmail originated posts filtered due to spam.

On Jul 21, 12:11*pm, HIPAR <captc...@verizon.net> wrote:
> PRN30 has been removed from the broadcast almanac.
> PRN01 has been included in the almanac:
>
> ******** Week 621 almanac for PRN-01 ********
> ID: * * * * * * * * * * * * 01
> Health: * * * * * * * * * * 063
> Eccentricity: * * * * * * * 0.2546310425E-003
> Time of Applicability(s): *589824.0000
> Orbital Inclination(rad): * 0.9600353241
> Rate of Right Ascen(r/s): *-0.7490598364E-008
> SQRT(A) *(m 1/2): * * * * * 5180.309570
> Right Ascen at Week(rad): *-0.1884143710E+001
> Argument of Perigee(rad): * 2.479846239
> Mean Anom(rad): * * * * * * 0.1795769095E+001
> Af0(s): * * * * * * * * * *-0.9536743164E-005
> Af1(s/s): * * * * * * * * * 0.0000000000E+000
> week: * * * * * * * * * * * *621
>
> --- *CHAS

Great !

Two questions:
1 - There's still a limitation of 31 Active PRNs (control segment
limited) ? If true, then PRN30 will be vacant until the next bird gets
decommissioned...
2 - Inclusion in the broadcast almanac doesn't imply activation of L-
band transmitters ?

Marcelo Pacheco

> > PRN30 has been removed from the broadcast almanac.
> > PRN01 has been included in the almanac:
>
> > ******** Week 621 almanac for PRN-01 ********
> > ID: * * * * * * * * * * * * 01
> > Health: * * * * * * * * * * 063
> > Eccentricity: * * * * * * * 0.2546310425E-003
> > Time of Applicability(s): *589824.0000
> > Orbital Inclination(rad): * 0.9600353241
> > Rate of Right Ascen(r/s): *-0.7490598364E-008
> > SQRT(A) *(m 1/2): * * * * * 5180.309570
> > Right Ascen at Week(rad): *-0.1884143710E+001
> > Argument of Perigee(rad): * 2.479846239
> > Mean Anom(rad): * * * * * * 0.1795769095E+001
> > Af0(s): * * * * * * * * * *-0.9536743164E-005
> > Af1(s/s): * * * * * * * * * 0.0000000000E+000
> > week: * * * * * * * * * * * *621
>
> > --- *CHAS
>
> Do you know which vehicle (model, #) this is?
>
>

Yes, sorry for the brevity of my report.

It's GPS IIF-2 (SVN63) launched into Plane D from the Cape 16 July.
It's transmitting but set unusable during an expected thirty day
commissioning.

NORAD:

Catalog 37753
NAVSTAR 66 (USA 232)

International designation:

2011-036A

Currently, SVN63 is moving through Plane D. Its currently completing
1.974 orbits per day. GPS satellites typically complete 2.006 orbits
per day. So, expect positioning maneuvers during commissioning.

--- CHAS

On 2011-07-21 12:35 , HIPAR wrote:
>>> PRN30 has been removed from the broadcast almanac.
>>> PRN01 has been included in the almanac:
>>
>>> ******** Week 621 almanac for PRN-01 ********
>>> ID: 01
>>> Health: 063
>>> Eccentricity: 0.2546310425E-003
>>> Time of Applicability(s): 589824.0000
>>> Orbital Inclination(rad): 0.9600353241
>>> Rate of Right Ascen(r/s): -0.7490598364E-008
>>> SQRT(A) (m 1/2): 5180.309570
>>> Right Ascen at Week(rad): -0.1884143710E+001
>>> Argument of Perigee(rad): 2.479846239
>>> Mean Anom(rad): 0.1795769095E+001
>>> Af0(s): -0.9536743164E-005
>>> Af1(s/s): 0.0000000000E+000
>>> week: 621
>>
>>> --- CHAS
>>
>> Do you know which vehicle (model, #) this is?
>>
>>
>
> Yes, sorry for the brevity of my report.
>
> It's GPS IIF-2 (SVN63) launched into Plane D from the Cape 16 July.
> It's transmitting but set unusable during an expected thirty day
> commissioning.
>
> NORAD:
>
> Catalog 37753
> NAVSTAR 66 (USA 232)
>
> International designation:
>
> 2011-036A
>
> Currently, SVN63 is moving through Plane D. Its currently completing
> 1.974 orbits per day. GPS satellites typically complete 2.006 orbits
> per day. So, expect positioning maneuvers during commissioning.

Sounds like they've inserted it slightly high until it 'backs' into
position, then they'll burn a bit and drop it to the correct orbit and
potentially mix that with an effort to make the orbit more circular ( I
didn't look at the almanac to see if it was more elliptical, just seems
to make sense to combine maneuvers to conserve reactive mass for the future)

--
gmail originated posts filtered due to spam.

On Jul 21, 12:07*pm, macpacheco <marc...@macp.eti.br> wrote:

> Great !
>
> Two questions:
> 1 - There's still a limitation of 31 Active PRNs (control segment
> limited) ? If true, then PRN30 will be vacant until the next bird gets
> decommissioned...
> 2 - Inclusion in the broadcast almanac doesn't imply activation of L-
> band transmitters ?
>
> Marcelo Pacheco

International monitors confirm SVN63 became active on L1 PRN01 some
time during 20 July. It's just an observation but I believe the
almanac lists all transmitting satellites. Evidently 31 usable
satellites will remain a limiting factor until OCX master control
comes on-line. But, I've seen 32 satellite almanacs with at least one
always set unusable.

The GPS IIF-3 launch satellite isn't scheduled but indications are it
will be happening about a year from now. It's most probably going to
Plane A to bolster the weak (SVN39, SVN27) pair currently guarding
prime slot A1.

So, if nothing breaks during the next year (unlikely), assignment of
recently PRN30 available seems likely.

--- CHAS

On Jul 21, 2:19*pm, HIPAR <captc...@verizon.net> wrote:
> On Jul 21, 12:07*pm, macpacheco <marc...@macp.eti.br> wrote:
>
> > Great !
>
> > Two questions:
> > 1 - There's still a limitation of 31 Active PRNs (control segment
> > limited) ? If true, then PRN30 will be vacant until the next bird gets
> > decommissioned...
> > 2 - Inclusion in the broadcast almanac doesn't imply activation of L-
> > band transmitters ?
>
> > Marcelo Pacheco
>
> International monitors confirm SVN63 became active on L1 PRN01 some
> time during 20 July. It's just an observation but I believe the
> almanac lists all transmitting satellites. *Evidently 31 usable
> satellites will remain a limiting factor until OCX master control
> comes on-line. *But, I've seen 32 satellite almanacs with at least one
> always set unusable.
>
> The GPS IIF-3 launch satellite isn't scheduled but indications are it
> will be happening about a year from now. *It's most probably going to
> Plane A to bolster the weak (SVN39, *SVN27) pair currently guarding
> prime slot A1.
>
> So, if nothing breaks during the next year (unlikely), *assignment of
> recently PRN30 available seems likely.
>
> --- *CHAS

Hi CHAS,

Don't we actually need another dead satellite before another launch ?

With PRN01 healthy in August, we'll be back to 31 healthy.

Perhaps PRN24 can be retired right before the next launch or PRN27
since it's the worst on orbit performance (at least for now).

Can the pre/post launch checks be performed with the 32nd PRN,
shutting down another healthy bird right before setting the new launch
healthy ?

One more thought, wouldn't it be more interesting to place PRN1 as a
wide trailing pair to PRN21 ? This would leave the D plane with 3
pairs instead of one triplet, one pair and a single bird. Leaving PRN1
as a wide trailing pair also puts it close to the PRN24/PRN11 pair, so
it could be moved quickly to a position closer to PRN11 than to PRN21
when PRN24 is retired. It also allows PRN1 to cover for PRN30
periodically as well as moving PRN6 forward would do the same for
different periods.

Marcelo Pacheco

On Jul 26, 11:44*pm, macpacheco <marc...@macp.eti.br> wrote:

> > --- *CHAS
>
> Hi CHAS,
>
> Don't we actually need another dead satellite before another launch ?
>
> With PRN01 healthy in August, we'll be back to 31 healthy.
>
> Perhaps PRN24 can be retired right before the next launch or PRN27
> since it's the worst on orbit performance (at least for now).
>
> Can the pre/post launch checks be performed with the 32nd PRN,
> shutting down another healthy bird right before setting the new launch
> healthy ?
>
> One more thought, wouldn't it be more interesting to place PRN1 as a
> wide trailing pair to PRN21 ? This would leave the D plane with 3
> pairs instead of one triplet, one pair and a single bird. Leaving PRN1
> as a wide trailing pair also puts it close to the PRN24/PRN11 pair, so
> it could be moved quickly to a position closer to PRN11 than to PRN21
> when PRN24 is retired. It also allows PRN1 to cover for PRN30
> periodically as well as moving PRN6 forward would do the same for
> different periods.
>
> Marcelo Pacheco


I don't think a 'dead' satellite is a prerequisite for launching a new
one. A launch as needed strategy certainly can be interpreted as
allowing replacement of a satellite that engineering telemetry
indicates might fail within the next year.

Block IIA satellites have been retiring at about one per year.

I'm still expecting GPS IIF-2 to replace SVN24 (PRN24). Don't forget
SVN24 was relocated for the 24+3 constellation. So the USAF will
place a reliable satellite close by supporting the expanded
configuration.

With the loss of SVN30 (PRN30) there is a 24+3 problem in Plane B.
Some potential solutions; one of them to be controversial:

1) Do nothing to restore Plane B; residual space vehicles not
suitable

2) Turn off PRN24, repair PRN30 and turn it back on; but it's
probably only marginally suitable

3) Turn off PRN24 and bring back and relocate residual SVN35 on
PRN30; it was tested prior to GPS IIF-2 launch?

4) Turn off PRN24 and set SVN49, the satellite with the anomalous
antenna radiation pattern, usable on PRN30

It's been said that, despite its anonymity, SVN49 performs equal to
many Block IIA satellites.

--- CHAS

On Jul 27, 9:19 pm, HIPAR <captc...@verizon.net> wrote:
> > Hi CHAS,
>
> > Don't we actually need another dead satellite before another launch ?
>
> > With PRN01 healthy in August, we'll be back to 31 healthy.
>
> > Perhaps PRN24 can be retired right before the next launch or PRN27
> > since it's the worst on orbit performance (at least for now).
>
> > Can the pre/post launch checks be performed with the 32nd PRN,
> > shutting down another healthy bird right before setting the new launch
> > healthy ?
>
> > One more thought, wouldn't it be more interesting to place PRN1 as a
> > wide trailing pair to PRN21 ? This would leave the D plane with 3
> > pairs instead of one triplet, one pair and a single bird. Leaving PRN1
> > as a wide trailing pair also puts it close to the PRN24/PRN11 pair, so
> > it could be moved quickly to a position closer to PRN11 than to PRN21
> > when PRN24 is retired. It also allows PRN1 to cover for PRN30
> > periodically as well as moving PRN6 forward would do the same for
> > different periods.
>
> > Marcelo Pacheco
>
> I don't think a 'dead' satellite is a prerequisite for launching a new
> one. A launch as needed strategy certainly can be interpreted as
> allowing replacement of a satellite that engineering telemetry
> indicates might fail within the next year.
>
> Block IIA satellites have been retiring at about one per year.
>
> I'm still expecting GPS IIF-2 to replace SVN24 (PRN24). Don't forget
> SVN24 was relocated for the 24+3 constellation. So the USAF will
> place a reliable satellite close by supporting the expanded
> configuration.
>
> With the loss of SVN30 (PRN30) there is a 24+3 problem in Plane B.
> Some potential solutions; one of them to be controversial:
>
> 1) Do nothing to restore Plane B; residual space vehicles not
> suitable
>
> 2) Turn off PRN24, repair PRN30 and turn it back on; but it's
> probably only marginally suitable
>
> 3) Turn off PRN24 and bring back and relocate residual SVN35 on
> PRN30; it was tested prior to GPS IIF-2 launch?
>
> 4) Turn off PRN24 and set SVN49, the satellite with the anomalous
> antenna radiation pattern, usable on PRN30
>
> It's been said that, despite its anonymity, SVN49 performs equal to
> many Block IIA satellites.
>
> --- CHAS

Hi Chas,

Some thoughts:

If the 32 PRN active (31 healthy and one unhealthy) is possible, I
would set PRN3 unhealthy and assign PRN30 healthy to either SVN35 or
SVN49.
On the SVN35 versus SVN49, WAAS was affected by SVN30 retirement, but
only very slightly so (only for LPV200, and about 0.1% impact), SBAS
operators stated they wouldn't use SVN49, although there's the
theoretical workaround of forcing SVN49 UDRE to 4.5meters minimum).
PRN3 could be set healthy again should PRN6 fail (considering that
PRN3/6 has PRN19 as a wide companion, so PRN19 can hold the slot for a
few hours until PRN3 is reactivated).

I'm assuming that setting one bird unhealthy doesn't prevent the
ground segment from tracking its clock and nav accuracy, allowing 2nd
SOPS to keep tabs on its performance, making it a hot spare.

SVN49 URE assessment showed 2.5 meter errors.
Currently PRN27 has UREs of 1.2m, around 1m for three other PRNs, and
all others below 90cm.
My source is http://adn.agi.com/GNSSWeb/PAFPSFViewer.aspx

But I'd rather use SVN49 than some really old residual that isn't
likely to live much longer anyways. Given that the B orbit gives birds
the lowest service life, wait as long as possible to replace PRN30
with a new bird.

If it were up to me, absent more failures, I would do two launches
next year. One to replace PRN27, another to replace both PRN3 and
PRN6, freeing up precious PRNs, allowing for more room in the
constellation's engineering, since PRN6 replacement would have PRN19
as a wide pair.

I see a scheduled DeltaV for PRN24. Hope that's a reposition. If so,
notice how PDOP will improve as PRN24 moves away from PRN11. It's one
of the constellation's current bottlenecks in geometry, specially when
the PRN11/24 pair flies close to the PRN 20/32 pair (about to happen
for the next two hours). Any increased distancing between PRN20 and
PRN32 that might be possible would also improve worst case PDOPs
substantially.

Marcelo