The U.S. military's newest Global Positioning System navigation
satellite is suffering from unusual signal distortions that will keep
it out of service for at least six months, the Air Force announced
Tuesday.

"The signal distortion was initially observed as an elevation-
dependent bias in ranging measurements from GPS monitor stations," the
Air Force said in a written statement from the Space and Missile
Systems Center.

See the whole story at spaceflightnow.com at

http://www.spaceflightnow.com/news/n0906/17gps2r20/

JT

The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang
--
Wolfgang S. Rupprecht Android 1.5 (Cupcake) and Fedora-11

Wolfgang S. Rupprecht wrote:
The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang
Press releases are written by PR people without the technical expertise
to provide a proper explanation. I for one would prefer that the
engineers spend the time fixing the problem. Even educating a highly
skilled engineer on a part of a subsystem is time consuming, think about
what it would take educate a administrator or PR person. Why do we as
users need to know the details?

Clair

On Jun 18, 6:08*am, Clair Johnston wrote:
Wolfgang S. Rupprecht wrote:
The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. *If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. *I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. *If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang

Press releases are written by PR people without the technical expertise
* to provide a proper explanation. *I for one would prefer that the
engineers spend the time fixing the problem. *Even educating a highly
skilled engineer on a part of a subsystem is time consuming, think about
* what it would take educate a administrator or PR person. *Why do we as
users need to know the details?

Clair

Granted for 99.9% of the users GPS is an appliance. That other 0.1%
who are industry oriented analysts or, maybe, just enthusiasts care a
lot about the details.

Eventually, an open technical explanation will be provided. I'm
interested in its details.

--- CHAS

Clair Johnston writes:
Press releases are written by PR people without the technical
expertise to provide a proper explanation. I for one would prefer
that the engineers spend the time fixing the problem. Even educating
a highly skilled engineer on a part of a subsystem is time consuming,
think about what it would take educate a administrator or PR person.
Why do we as users need to know the details?

NASA does a much better job of projecting competence by coming out with
explanations (or just credible theories when facts are still scarce).
It gives the listener the feeling that they are on top of the situation
and are getting things under control.

I guess I'm getting very spoiled by working with scientists and skilled
engineers. I expect people when asked what the problem is to give a
proper explanation and not something made up by a PR person with a very
limited understanding of the subject.

I don't think it would be a bad idea for an engineer working on this
problem to write up a short explanation. Explaining something and
simplifying it *slightly* for the audience is a great way to go over the
facts in your head and usually causes one to notice holes and get new
insights. It is also a great way for the listener to learn a little
about a new field and understand some of the not so obvious pitfalls.

-wolfgang
--
Wolfgang S. Rupprecht Android 1.5 (Cupcake) and Fedora-11

Wolfgang S. Rupprecht wrote:
Clair Johnston writes:
Press releases are written by PR people without the technical
expertise to provide a proper explanation. I for one would prefer
that the engineers spend the time fixing the problem. Even educating
a highly skilled engineer on a part of a subsystem is time consuming,
think about what it would take educate a administrator or PR person.
Why do we as users need to know the details?

NASA does a much better job of projecting competence by coming out with
explanations (or just credible theories when facts are still scarce).
It gives the listener the feeling that they are on top of the situation
and are getting things under control.
Maybe, but NASA is used to PR and being in the public eye.

I guess I'm getting very spoiled by working with scientists and skilled
engineers. I expect people when asked what the problem is to give a
proper explanation and not something made up by a PR person with a very
limited understanding of the subject.
So you want tax payer money spent to appease the curious. It is also
possible that the description you desire may contain classified information.

I don't think it would be a bad idea for an engineer working on this
problem to write up a short explanation. Explaining something and
simplifying it *slightly* for the audience is a great way to go over the
facts in your head and usually causes one to notice holes and get new
insights. It is also a great way for the listener to learn a little
about a new field and understand some of the not so obvious pitfalls.
As a former engineer and engineering manager I was involved in a number
of "crisis" events. I always appreciated a supervisor who protected me
from the curious, and I did the same for those who worked for me. A
team of engineers working together will fix the problem faster that an
engineer putting together a "slightly" simplified description of the
problem for the curious. If you have a large team (NASA) then assigning
a junior engineer as a PR person might make sense.

-wolfgang

"Wolfgang S. Rupprecht" schrieb im
Newsbeitrag ...

The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang
--
Wolfgang S. Rupprecht Android 1.5 (Cupcake) and Fedora-11

To my understanding of the problem it is in fact easy to do a "work around"
and in fact that is what is being done right now. However, the work around
reduces the problem to a great extend for normal users but will not resolve
it for the "high end" users (those at the 1 to 100 mm level). Also it does
not explain where the problem is coming from in the first place and neither
resolves the problem, it is just a "work around". However, it seems that
they have found the "root" of the problem but it can not be fixed.
Tim
http://gnss.servolux.nl

On Jun 17, 11:47*pm, "Wolfgang S. Rupprecht" wolfgang.rupprecht
wrote:
The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. *If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. *I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. *If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang
--
Wolfgang S. Rupprecht * * * * * * *Android 1.5 (Cupcake) and Fedora-11

What you have is the data. Follow the link to be found here, see page
35.
http://groups.google.com/group/sci.g...6b6bbae20c05f2

Now think. They bolted on an L5 transmitter but it feeds a single
phased array antenna, the same phased array antenna feed by the L1
transmitter. The IIRM birds were not designed with an extra connector
ready made for a new transmitter. I am guessing that the interface to
the phased array antenna had to be changed and changed in a hurry.
Somebody at ITT (I am guessing) made a judgment about swapping in a
new interface that did have a new connector. Clearly that new
interface didn't work as expected.

The wing has limited funds. I am guessing that a decision was made to
not spend the money needed to do near and far field testing. What
kind of technical advice the wing got and what they did with it is
unknown.

You lay down your money and you take your chances.

--Mike Jr

On Jun 18, 6:08*am, Clair Johnston wrote:
Wolfgang S. Rupprecht wrote:
The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. *If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. *I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. *If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang

Press releases are written by PR people without the technical expertise
* to provide a proper explanation. *I for one would prefer that the
engineers spend the time fixing the problem. *Even educating a highly
skilled engineer on a part of a subsystem is time consuming, think about
* what it would take educate a administrator or PR person. *Why do we as
users need to know the details?

Clair

I disagree. Trained engineers are capable of explaining complicated
things to management.

I see the wing playing politics. October for an end date was very
telling; keep the lid on to buy time. While GPS is rocket science,
politics is not.

--Mike Jr

On Jun 18, 6:37*pm, "Tim Springer"
wrote:
"Wolfgang S. Rupprecht" schrieb im
...





The Air Force has identified the cause of signal anomalies for PRN01
and will attempt to work around the problem. *If they can do that
PRN01 might be set usable this fall.

http://www.insidegnss.com/node/1573

While I'm really happy that the military provides the GPS for our use,
the announcements they issue read like a bad joke about military
intelligence. *I've read about a dozen reports now that "a signal
anomaly has been detected and they think they can correct it", but the
reports all stop there. *If they really know what is going wrong why
isn't there a proper explanation in that press release?

-wolfgang
--
Wolfgang S. Rupprecht * * * * * * *Android 1.5 (Cupcake) and Fedora-11

To my understanding of the problem it is in fact easy to do a "work around"
and in fact that is what is being done right now. However, the work around
reduces the problem to a great extend for normal users but will not resolve
it for the "high end" users (those at the 1 to 100 mm level). Also it does
not explain where the problem is coming from in the first place and neither
resolves the problem, it is just a "work around". However, it seems that
they have found the "root" of the problem but it can not be fixed.
Timhttp://gnss.servolux.nl

Obviously nobody can go 'up there' and disconnect the L5 transmitter
from the antenna farm so yes, the root problem cannot be fixed.

My guess is the 'work around' will adjust the navigation message
parameters that estimate the ionospheric time delay. There's a user
equipment equation that accepts these parameters and the satellite
elevation and azimuth as variables.

--- CHAS