According to WAAS Satellite status pictures, SVN63 (IIF-2/PRN1) is
very close to PRN11 (D2-F), and should arrive at D2-A slot in less
than 48 hrs. Since PRN24 is still working fine, I'm hoping they will
let SVN63 move further west, assuming a configuration similar to
PRN19/3/6 (with SVN63 having a good space west of PRN24).

SVN35 so far is showing clock/ephemeris performance worse than SVN27,
but SBAS and other augmentation systems can correct for that, while
SVN49 multipath error might not be so correctable by augmentations,
since the actual error is receiver dependent (a function of the
receiver's resistance to multipath). Lets just hope SVN35 can live at
least a couple of years.

Marcelo Pacheco

On Aug 13, 11:14*pm, macpacheco <marc...@macp.eti.br> wrote:
> According to WAAS Satellite status pictures, SVN63 (IIF-2/PRN1) is
> very close to PRN11 (D2-F), and should arrive at D2-A slot in less
> than 48 hrs. Since PRN24 is still working fine, I'm hoping they will
> let SVN63 move further west, assuming a configuration similar to
> PRN19/3/6 (with SVN63 having a good space west of PRN24).
>
> SVN35 so far is showing clock/ephemeris performance worse than SVN27,
> but SBAS and other augmentation systems can correct for that, while
> SVN49 multipath error might not be so correctable by augmentations,
> since the actual error is receiver dependent (a function of the
> receiver's resistance to multipath). Lets just hope SVN35 can live at
> least a couple of years.
>
> Marcelo Pacheco

My satellite tracking software also shows GPS IIF-2 to be behind PRN11
with PRN24 approaching . The latest orbital data (Day 225) shows GPS
IIF-2 Mean Motion remains at 1.97479 revolutions/day.

So, running the simulation for GPS IIF-2 until it drifts behind PRN24,
I'd suspect it will reach its place sometime during 18 Aug. If the
intent is to directly replace PRN24, then GPS IIF-2 will be in
position sometime between Aug 16 -17.

I would expect to see a notice that PRN24 is to be UNUSUFN or
decommissioned if the intent is to directly replace it.

Over in Plane B, SVN35 sending PRN30 (unusable) is currently orbiting
close to GPS IIF-1 (PRN25). It completes 2.003568 revolutions per day
so It will be on station to replace decommissioned SVN30 late this
year but it should be set usable well before then.

Just a few 'semi-educated' guesses for fun about what's happening.

--- CHAS

On Aug 13, 11:14*pm, macpacheco <marc...@macp.eti.br> wrote:
> According to WAAS Satellite status pictures, SVN63 (IIF-2/PRN1) is
> very close to PRN11 (D2-F), and should arrive at D2-A slot in less
> than 48 hrs. Since PRN24 is still working fine, I'm hoping they will
> let SVN63 move further west, assuming a configuration similar to
> PRN19/3/6 (with SVN63 having a good space west of PRN24).
>
> SVN35 so far is showing clock/ephemeris performance worse than SVN27,
> but SBAS and other augmentation systems can correct for that, while
> SVN49 multipath error might not be so correctable by augmentations,
> since the actual error is receiver dependent (a function of the
> receiver's resistance to multipath). Lets just hope SVN35 can live at
> least a couple of years.
>
> Marcelo Pacheco

Indications of final SVN63 positioning

SVN63 almanac values:

SQRT(A) (m 1/2) -- relates to height and period of orbit

Sat 13 Aug 5180.3
Sun 14 Aug 5180.3
Mon 15 Aug 5173.4
Tue 16 Aug 5166.4

Nominal value for GPS is 5153.7

--- CHAS

On Aug 16, 3:01*pm, HIPAR <captc...@verizon.net> wrote:
> On Aug 13, 11:14*pm, macpacheco <marc...@macp.eti.br> wrote:
>
> > According to WAAS Satellite status pictures, SVN63 (IIF-2/PRN1) is
> > very close to PRN11 (D2-F), and should arrive at D2-A slot in less
> > than 48 hrs. Since PRN24 is still working fine, I'm hoping they will
> > let SVN63 move further west, assuming a configuration similar to
> > PRN19/3/6 (with SVN63 having a good space west of PRN24).
>
> > SVN35 so far is showing clock/ephemeris performance worse than SVN27,
> > but SBAS and other augmentation systems can correct for that, while
> > SVN49 multipath error might not be so correctable by augmentations,
> > since the actual error is receiver dependent (a function of the
> > receiver's resistance to multipath). Lets just hope SVN35 can live at
> > least a couple of years.
>
> > Marcelo Pacheco
>
> Indications of *final SVN63 positioning
>
> SVN63 almanac values:
>
> SQRT(A) *(m 1/2) *-- relates to height and period of orbit
>
> Sat * *13 Aug * 5180.3
> Sun * 14 Aug * 5180.3
> Mon * 15 Aug * 5173.4
> Tue * *16 Aug * 5166.4
>
> Nominal value for GPS is 5153.7
>
> --- *CHAS

SVN63 is now clearly west of PRN24.
It looks like its going through a DeltaV event right now (2117Z
08/16/11) - WAAS showing its status DNU instead of the usual NM.
Please, let SVN63 continue its westward drift, for a wide pair like
PRN5/10. It does wonders for PDOP.
Anyhow, with SVN63 in position, and just over a month since it's
launch, it should be ripe for going healthy any day now.

Also SVN35 was just set healthy:
NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2011062 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
GPS SATELLITE SVN35 (PRN30) WAS USABLE AS OF JDAY 228 (16 AUG 2011)
BEGINNING AT 2045Z
*** GENERAL MESSAGE TO ALL GPS USERS ***

Marcelo

>
> Indications of *final SVN63 positioning
>
> SVN63 almanac values:
>
> SQRT(A) *(m 1/2) *-- relates to height and period of orbit
>
> Sat * *13 Aug * 5180.3
> Sun * 14 Aug * 5180.3
> Mon * 15 Aug * 5173.4
> Tue * *16 Aug * 5166.4
>
> Nominal value for GPS is 5153.7
>

Fri 19 Aug

SQRT(A) (m 1/2): 5153.615723

It's on station.

--- CHAS

On Aug 19, 12:43*pm, HIPAR <captc...@verizon.net> wrote:
> > Indications of *final SVN63 positioning
>
> > SVN63 almanac values:
>
> > SQRT(A) *(m 1/2) *-- relates to height and period of orbit
>
> > Sat * *13 Aug * 5180.3
> > Sun * 14 Aug * 5180.3
> > Mon * 15 Aug * 5173.4
> > Tue * *16 Aug * 5166.4
>
> > Nominal value for GPS is 5153.7
>
> Fri 19 Aug
>
> SQRT(A) *(m 1/2): * * * * * 5153.615723
>
> It's on station.
>
> --- *CHAS

On the positive side, great, 2nd SOPS should be able to set SVN63
healthy in the next few days. If all the tests are done, they could
set it healthy today.
On the flip side, SVN63 is within shouting distance to PRN24... Even
if PRN24 was already decommissioned, more spacing (SVN63 further west)
with PRN11 would have been positive for PDOPs, as much as 150% more
spacing to PRN11.
I'll keep up the constructive criticism... Nothing personal, the plans
for GPS are too conservative, inefficient. Spreading the pairs further
would make GPS as good as Galileo is planned to be. Leave it the way
it is, and Galileo will kick its ass. And spreading the pairs and
stopping with triplets completely (right now there are two triplets in
the constellation), would allow for two extra efficient wide pairs to
be formed.
C'mon guys, take advantage of those birds living longer and longer and
longer.

Marcelo

On Aug 19, 1:57*pm, macpacheco <marc...@macp.eti.br> wrote:
>
> On the positive side, great, 2nd SOPS should be able to set SVN63
> healthy in the next few days. If all the tests are done, they could
> set it healthy today.
> On the flip side, SVN63 is within shouting distance to PRN24... Even
> if PRN24 was already decommissioned, more spacing (SVN63 further west)
> with PRN11 would have been positive for PDOPs, as much as 150% more
> spacing to PRN11.
> I'll keep up the constructive criticism... Nothing personal, the plans
> for GPS are too conservative, inefficient. Spreading the pairs further
> would make GPS as good as Galileo is planned to be. Leave it the way
> it is, and Galileo will kick its ass. And spreading the pairs and
> stopping with triplets completely (right now there are two triplets in
> the constellation), would allow for two extra efficient wide pairs to
> be formed.
> C'mon guys, take advantage of those birds living longer and longer and
> longer.
>
> Marcelo

SVN24/PRN24 is a tired old satellite that consistently exhibits one of
the poorest signal in space (SIS) errors, often in excess of 2 meters.
What can it contribute?

We do not need it to backup GPS IIF-2. We should not need that brand
new satellite exhibiting a SIS error of 0.5 meters to backup SVN24.
As you contend, SVN24 cannot materially increase constellation
effectiveness by improving DOP.

So, I can envision a scenario when its SIS error actually increases
the position error when my GPS receiver uses it for computing the fix.

I don't think the USAF will be concerned about competing with
Galileo. Their first priority will remain service to the DoD but I'm
sure they are serious about providing quality signals to their civil
users. The world GNSS/GIS community will keep them honest about that.

Having learned from 30 years of GPS operations, Galileo will enter as
a modernized system with no concern about servicing legacy users.
When Galileo goes operational, if it really is a superior system, so
be it.

--- CHAS

On Aug 19, 6:19*pm, HIPAR <captc...@verizon.net> wrote:
> On Aug 19, 1:57*pm, macpacheco <marc...@macp.eti.br> wrote:
>
>
>
>
>
>
>
>
>
>
>
> > On the positive side, great, 2nd SOPS should be able to set SVN63
> > healthy in the next few days. If all the tests are done, they could
> > set it healthy today.
> > On the flip side, SVN63 is within shouting distance to PRN24... Even
> > if PRN24 was already decommissioned, more spacing (SVN63 further west)
> > with PRN11 would have been positive for PDOPs, as much as 150% more
> > spacing to PRN11.
> > I'll keep up the constructive criticism... Nothing personal, the plans
> > for GPS are too conservative, inefficient. Spreading the pairs further
> > would make GPS as good as Galileo is planned to be. Leave it the way
> > it is, and Galileo will kick its ass. And spreading the pairs and
> > stopping with triplets completely (right now there are two triplets in
> > the constellation), would allow for two extra efficient wide pairs to
> > be formed.
> > C'mon guys, take advantage of those birds living longer and longer and
> > longer.
>
> > Marcelo
>
> SVN24/PRN24 is a tired old satellite that consistently exhibits one of
> the poorest signal in space (SIS) errors, often in excess of 2 meters.
> What can it contribute?
>
> We do not need it to backup GPS IIF-2. *We should not need that brand
> new satellite exhibiting a SIS error of *0.5 meters to backup SVN24.
> As you contend, SVN24 cannot materially increase constellation
> effectiveness by improving DOP.
>
> So, I can envision a scenario when its SIS error actually increases
> the position error when my GPS receiver uses it for computing the fix.
>
> I don't think the USAF will be concerned about competing with
> Galileo. *Their first priority will remain service to the DoD but I'm
> sure they are serious about providing quality signals to their civil
> users. *The world GNSS/GIS community will keep them honest about that.
>
> Having learned from 30 years of GPS operations, Galileo will enter as
> a modernized system with no concern about servicing legacy users.
> When Galileo goes operational, if it really is a superior system, so
> be it.
>
> --- *CHAS

SVN63 control just turned over to 2nd SOPS, meaning its checkout
complete, and no more to do's before going healthy.
http://www.gpsworld.com/gnss-system/...atellite-12004

The point about the position of SVN63 is to let GPS be as good as it
can be. It can be better, providing military and high accuracy users
with even better performance. The comparison to Galileo is a teaser,
but shouldn't be the main reason to pursue improvements. I'll address
that in another thread soon.

Marcelo Pacheco

On 2011-08-19 17:19 , HIPAR wrote:
> On Aug 19, 1:57 pm, macpacheco<marc...@macp.eti.br> wrote:
>>
>> On the positive side, great, 2nd SOPS should be able to set SVN63
>> healthy in the next few days. If all the tests are done, they could
>> set it healthy today.
>> On the flip side, SVN63 is within shouting distance to PRN24... Even
>> if PRN24 was already decommissioned, more spacing (SVN63 further west)
>> with PRN11 would have been positive for PDOPs, as much as 150% more
>> spacing to PRN11.
>> I'll keep up the constructive criticism... Nothing personal, the plans
>> for GPS are too conservative, inefficient. Spreading the pairs further
>> would make GPS as good as Galileo is planned to be. Leave it the way
>> it is, and Galileo will kick its ass. And spreading the pairs and
>> stopping with triplets completely (right now there are two triplets in
>> the constellation), would allow for two extra efficient wide pairs to
>> be formed.
>> C'mon guys, take advantage of those birds living longer and longer and
>> longer.
>>
>> Marcelo
>
> SVN24/PRN24 is a tired old satellite that consistently exhibits one of
> the poorest signal in space (SIS) errors, often in excess of 2 meters.
> What can it contribute?
>
> We do not need it to backup GPS IIF-2. We should not need that brand
> new satellite exhibiting a SIS error of 0.5 meters to backup SVN24.
> As you contend, SVN24 cannot materially increase constellation
> effectiveness by improving DOP.
>
> So, I can envision a scenario when its SIS error actually increases
> the position error when my GPS receiver uses it for computing the fix.
>
> I don't think the USAF will be concerned about competing with
> Galileo. Their first priority will remain service to the DoD but I'm
> sure they are serious about providing quality signals to their civil
> users. The world GNSS/GIS community will keep them honest about that.
>
> Having learned from 30 years of GPS operations, Galileo will enter as
> a modernized system with no concern about servicing legacy users.
> When Galileo goes operational, if it really is a superior system, so
> be it.
>
> --- CHAS
>


--
gmail originated posts filtered due to spam.

On 2011-08-19 17:19 , HIPAR wrote:

> SVN24/PRN24 is a tired old satellite that consistently exhibits one of
> the poorest signal in space (SIS) errors, often in excess of 2 meters.
> What can it contribute?
>
> We do not need it to backup GPS IIF-2. We should not need that brand
> new satellite exhibiting a SIS error of 0.5 meters to backup SVN24.
> As you contend, SVN24 cannot materially increase constellation
> effectiveness by improving DOP.
>
> So, I can envision a scenario when its SIS error actually increases
> the position error when my GPS receiver uses it for computing the fix.
>
> I don't think the USAF will be concerned about competing with
> Galileo. Their first priority will remain service to the DoD but I'm
> sure they are serious about providing quality signals to their civil
> users. The world GNSS/GIS community will keep them honest about that.
>
> Having learned from 30 years of GPS operations, Galileo will enter as
> a modernized system with no concern about servicing legacy users.
> When Galileo goes operational, if it really is a superior system, so
> be it.

In the end, Galileo will be complementary, just as GLONASS will be
complementary.

I don't think obsessing over the 2m SIS of SVN24 is all that useful -
though it would be nice if we could tell our receivers to ignore it.

Perhaps, once 63 is declared in position and healthy, they'll set the
health bit for 24 to bad and keep it available as a backup until it
ultimately fails.

http://www.nstb.tc.faa.gov/RT_WaasSatelliteStatus.htm

Is SVN63 PRN 1 on there (right behind 24)?


--
gmail originated posts filtered due to spam.