After looking into the details of the SVN49 anomaly we have now discovered
that more GPS Block IIR and IIR-M satellites may be suffering from the same
root cause. Have a look at the latest information on my blog or on
InsideGNSS

My blog:http://gnss.servolux.nl/gnss_blog.html

InsideGNSS:http://www.insidegnss.com/node/1599

After looking into the details of the SVN49 anomaly we have now discovered
that more GPS Block IIR and IIR-M satellites may be suffering from the same
root cause. Have a look at the latest information on my blog or on
InsideGNSS

My blog:http://gnss.servolux.nl/gnss_blog.html

InsideGNSS:http://www.insidegnss.com/node/1599

Could be and probably worthy of some investigation, but no one will
argue about the performance of the current constellation. But they
will debate whether SVN49 should be included in the current
constellation.

Could be and probably worthy of some investigation, but no one will
argue about the performance of the current constellation. But they
will debate whether SVN49 should be included in the current
constellation.

Certainly Tim's investigation should put the Air Force on notice that
someone is independently checking their work.  Hopefully, the GPS IIF
and GPS III satellites will be scrutinized for these kinds of issues.

---  CHAS

"HIPAR" <captc...@verizon.net> wrote in message

news:d922fa82-cf37-4b84-a6ac-06246690c9a3@h18g2000yqj.googlegroups.com...

Certainly Tim's investigation should put the Air Force on notice that
someone is independently checking their work.  Hopefully, the GPS IIF
and GPS III satellites will be scrutinized for these kinds of issues.

[snip]
On the other hand, since he sees the effect only on certain PRNs, I'm fairly
sure he's drawing the correct conclusions.

Marty,

On Jul 19, 2:54 pm, "Tim Springer" <Tim-Springer-nos...@t-online.de
wrote:

After looking into the details of the SVN49 anomaly we have now discovered
that more GPS Block IIR and IIR-M satellites may be suffering from the same
root cause. Have a look at the latest information on my blog or on
InsideGNSS

My blog:http://gnss.servolux.nl/gnss_blog.html

InsideGNSS:http://www.insidegnss.com/node/1599

Now that we have discovered NAVSTAR is orbiting space junk, can
someone direct me to an xTex class hand held GLONASS receiver ?

---  CHAS

Certainly Tim's investigation should put the Air Force on notice that
someone is independently checking their work. Hopefully, the GPS IIF
and GPS III satellites will be scrutinized for these kinds of issues.

On Jul 19, 2:54 pm, "Tim Springer" <Tim-Springer-nos...@t-online.de
wrote:

After looking into the details of the SVN49 anomaly we have now discovered
that more GPS Block IIR and IIR-M satellites may be suffering from the same
root cause. Have a look at the latest information on my blog or on
InsideGNSS

My blog:http://gnss.servolux.nl/gnss_blog.html

InsideGNSS:http://www.insidegnss.com/node/1599

SVN49 problem was caused by impedance miss match with the L5
demonstration payload.  It is a unique configuration.  The elevation
dependent pseudorange error is not seen on other satellites.

                 Tom

Between this and the GAO report, the heat in the kitchen has certainly
risen at the GPS Wing.
[snip]

On Jul 21, 9:18 pm, GPSGUY <sat_ali...@yahoo.com> wrote:
Between this and the GAO report, the heat in the kitchen has certainly
risen at the GPS Wing.
[snip]

History has taught us that the best way to handle a mistake is:
1. Admit it
2. Fix it
3. Don't repeat it

You can't fix a problem that you don't admit exists.

The wing seems to treat engineering as a commodity, like electricity.
"GPS is settled science/engineering; I can plug any component, any
product, and any company's engineering talent in and it will work."
Nothing could be a bigger mistake. Until the wing admits and fixes
this mistake they will continue to be plagued by these kinds of
problems.

"Mike Jr" <n00s...@comcast.net> schrieb im Newsbeitragnews:31434325-6c65-4014-89da-785ec56d8079@q35g2000vbi.googlegroups.com...



On Jul 21, 9:18 pm, GPSGUY <sat_ali...@yahoo.com> wrote:
Between this and the GAO report, the heat in the kitchen has certainly
risen at the GPS Wing.
[snip]

Personally I find the behavior of the GPS wing with respect to the SVN49
issue quite professional. They have admitted to the problem very quickly and
even managed to find the cause and explain it to the public. This is much
better and much more "open" communications then I experience with the
European counterpart of GPS named Galileo. Despite the fact that Galileo is
NOT a military system everything is treated as "top secret" and no one is
allowed to publish anything without prior approval of the EU and/or ESA.
Really a very surprising and very disappointing and frustrating situation
for a "public" system build with "public" money.

So from me a big compliment to the GPS wing! I really love the GPS system
and the performance of it is truly great. Of course the SVN49 is a bit of a
"hick-up" but at least it has secured the L5 frequency. Europe had to launch
two test satellites (Giove-A and Giove-B) to secure its frequencies and the
usefulness of those two is really limited.

For the users of the GPS system SVN49 really does not pose much of a
problem. A simple polynomial model can remove the issue and make the
satellite fully usable. Whether all cheap GPS chips as used in mobile phones
and such will implement such a correction is an open question. But at least
all "post processing" software can easily correct the issue.