GPS - Part IV.
 

"Tom Francis" wrote in message
...
Well, after investigating a little, visiting the newsgroup that RG
suggested and talking to a CG MSO this morning when I went down to New
London for a sea trial, it appears there are several factors
contributing to this.

1 - There are apparently three birds in the Northern satellite
constellation that are experiencing service outages - the problems are
intermittent and while these birds are due for replacement in upcoming
months, keeping them running is a hit or miss proposition.

2 - Add to this the CG, NASA, NOAA and Air Force are performing GPS
Satellite interference tests all this month and this year in selected
areas of the country. In theory, this is supposed to end in the NE
part of the country by October 13th.

3 - There is some low level solar flare activity that is causing
signal fade and minor corrections in satellite orbits which brings
them down temporarily.

4 - The Air Force has been screwing around with some air defense
radars along the East Coast that are close in wave length to that used
by the GPS constellation although this has been limited if only
because of the effect it has on local communications.

5 - Air Force has been testing the intentional error software in the
Northern Constellation.

6 - RFI/EMI from appliances that theoretically have FCC approval, but
have manufacturing tolerance problems.

So to put paid to all this, it's a combination of technical issues, it
is real, but very intermittent and certain receivers are more
susceptible to the problem than others - depends on how the software
is written, how sensitive the receiver is and receiver antenna
location. Also the further North you are, the worse it becomes when
it does happen.

Pretty cool huh?

You missed the obvious.
It's all Bush's fault.

Eisboch

GPS - Part IV.
 

Eisboch wrote:
"Tom Francis" wrote in message
...
Well, after investigating a little, visiting the newsgroup that RG
suggested and talking to a CG MSO this morning when I went down to New
London for a sea trial, it appears there are several factors
contributing to this.

1 - There are apparently three birds in the Northern satellite
constellation that are experiencing service outages - the problems are
intermittent and while these birds are due for replacement in upcoming
months, keeping them running is a hit or miss proposition.

2 - Add to this the CG, NASA, NOAA and Air Force are performing GPS
Satellite interference tests all this month and this year in selected
areas of the country. In theory, this is supposed to end in the NE
part of the country by October 13th.

3 - There is some low level solar flare activity that is causing
signal fade and minor corrections in satellite orbits which brings
them down temporarily.

4 - The Air Force has been screwing around with some air defense
radars along the East Coast that are close in wave length to that used
by the GPS constellation although this has been limited if only
because of the effect it has on local communications.

5 - Air Force has been testing the intentional error software in the
Northern Constellation.

6 - RFI/EMI from appliances that theoretically have FCC approval, but
have manufacturing tolerance problems.

So to put paid to all this, it's a combination of technical issues, it
is real, but very intermittent and certain receivers are more
susceptible to the problem than others - depends on how the software
is written, how sensitive the receiver is and receiver antenna
location. Also the further North you are, the worse it becomes when
it does happen.

Pretty cool huh?

You missed the obvious.
It's all Bush's fault.

Eisboch

Yuh, them golldurned pinko bedwetting, traitor, treasonous, sumbitch,
homo tolerating liburuls think everything is his fault. They're all
going to go to hell because Bush talks to God every day, and God talks
back, telling him who to go to war with.

GPS - Part IV.
 

"Tom Francis" wrote in message
...

Goes without saying that Cheney/Rumsfield are doing this to screw up
the economy and providing a reason to invade Canada because they found
the RFI problem with the Radio Shack, a US Company, marine TV
receiver.


The issue with the marine TV antenna has been around for a long time and I
am surprised it is still considered a problem. I believe the antenna in
question was made by Shakespeare and the interference originated from the
preamp that is mounted in the unit. It was discovered to be emitting RFI
and if it was mounted within something like 8 feet from the GPS antenna it
was enough to disrupt the very weak GPS signal. I had that problem on the
Navigator when it was first commissioned. The GPS head was within 3 feet of
the TV antenna.

We exchanged the TV antenna with a new, "improved" version that Shakespeare
offered as a swap and the problem went away.

Eisboch

GPS - Part IV.
 

Tom Francis wrote:


Goes without saying that Cheney/Rumsfield are doing this to screw up
the economy and providing a reason to invade Canada because they found
the RFI problem with the Radio Shack, a US Company, marine TV
receiver.

snip...


Cheney??? We ran his people out of this area well over a hundred years
ago. If he comes this way...we'll do it again!
His ancestor homestead..
http://www.angelfire.com/nb/deb/cheneyisland.html