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May 24th 05, 01:09 AM
I have been told that GPS Interference Testing is taking place. Several
folks are reporting a drop in signal which they then lose final glide
information. Several of our pilots had seriously intermittant GPS
signals on Monday, May 16. Here is an explanation:

http://www.navcen.uscg.gov/gps/gpsnotices and
http://www.navcen.uscg.gov/gps/gpsnotices/GPS_Interference.pdf

Usually the tests are from 8pm-4am on most days for us here in NM.
They might only affect us on final glide on a good, long day.

>From May 16-21, they are from 4pm-2am....this explains the trouble
pilots had yesterday.

>From 22 June to 02 July, they will take place from 3pm-1am.

So, goe to the above site and check for your area, its possible your
area will be affected even if its not listed. Thermal tight, Soar high,
fly safe. # 711 reporting

5Z
May 24th 05, 03:57 AM
Looks like weekday soaring along the southern Sierras in CA will be
affected in June, July and August.

01-03, 06-10 JUN05
13-17, 20-24 JUN05
27-30 JUN05
06-08, 11-15 JUL05
18-22, 25-29 JUL05
01-05, 08-12 AUG05
15-19, 22-26 AUG05
29-31 AUG05

Times below are local for the above dates
0330-0500
0730-1100
1300-1700
AND
2030-2200

P. Corbett
May 27th 05, 06:56 AM
This schedule will not only have a negative affect on weekday badge and
record flying in the affected areas but also on all GPS receivers. This will
likey include all handhelds used by hikers and emergency services etc. I
thought the GPS system in this country is for public use. Is this program
legal? Do we have any recourse? Any thoughts on this?

Paul Corbett
ZZ

May 27th 05, 02:24 PM
GPS is funded by and controlled by the U. S. Department of Defense
(DOD). While there are many thousands of civil users of GPS world-wide,
the system was designed for and is operated by the U. S. military.

IIRC, President Clinton decreed that the GPS system be made available
for public use. But that was not its original purpose, nor is it now
its first priority. If the DOD wants to take it off line for testing,
that's their prerogative.

Marc Ramsey
May 27th 05, 06:27 PM
wrote:
> IIRC, President Clinton decreed that the GPS system be made available
> for public use. But that was not its original purpose, nor is it now
> its first priority. If the DOD wants to take it off line for testing,
> that's their prerogative.

I have no time to track down appropriate references, but this is not
correct. Part of the negotiation that resulted in the executive order
involved the DOD giving up the right to do routine area denial
exercises, in exchange for a significant portion of the funding for GPS
upgrades being moved to the civilian budget. In particular,
"operational" use of GPS for safety critical civilian uses was delayed,
in order to provide the military adequate time to develop appropriate
jamming technology. That period has been over for a number of years.
GPS approaches are in routine use. ADS-B is being deployed nationwide.
Cellphone E911 systems are dependent on GPS. Railroad signaling
systems are now heavily GPS based. The DOD no longer has the
"prerogative" to deny GPS within the US whenever they feel like it. Of
course, the US military is no longer accountable to anyone except Donald
Rumsfeld, so I don't expect anyone to particularly care, until a
GPS-related accident results in a major loss of life.

And, people wondered why the Europeans felt the need to build their own
civilian positioning system...

Paul Lynch
May 27th 05, 06:33 PM
Ignoring your political rant...

The military does occassionally test GPS jammers to test their ability to
operate in a GPS jamming environment. Those events are relatively localized
and are NOTAM'd events. They are predominantly done at sea so as to disrupt
as few as possible, and to a smaller scale in restricted areas where the
impact is minimized.


"Marc Ramsey" > wrote in message
m...
> wrote:
>> IIRC, President Clinton decreed that the GPS system be made available
>> for public use. But that was not its original purpose, nor is it now
>> its first priority. If the DOD wants to take it off line for testing,
>> that's their prerogative.
>
> I have no time to track down appropriate references, but this is not
> correct. Part of the negotiation that resulted in the executive order
> involved the DOD giving up the right to do routine area denial exercises,
> in exchange for a significant portion of the funding for GPS upgrades
> being moved to the civilian budget. In particular, "operational" use of
> GPS for safety critical civilian uses was delayed, in order to provide the
> military adequate time to develop appropriate jamming technology. That
> period has been over for a number of years. GPS approaches are in routine
> use. ADS-B is being deployed nationwide. Cellphone E911 systems are
> dependent on GPS. Railroad signaling systems are now heavily GPS based.
> The DOD no longer has the "prerogative" to deny GPS within the US whenever
> they feel like it. Of course, the US military is no longer accountable to
> anyone except Donald Rumsfeld, so I don't expect anyone to particularly
> care, until a GPS-related accident results in a major loss of life.
>
> And, people wondered why the Europeans felt the need to build their own
> civilian positioning system...
>
>

Tim Harrison
May 28th 05, 09:12 AM
Thank you for this advisory.
Can you please tell me how far inside the proclaimed jamming area the
pilots, who lost GPS signals, were flying?
The published radius from China Lake is approx 180 NM at 15,000ft - a huge
area if thinking of the Whites etc.
Is it possible that the area is the maximum likely and the real jamming area
might be somewhat smaller (and affected by terrain)?

Tim

> wrote in message
ups.com...
>I have been told that GPS Interference Testing is taking place. Several
> folks are reporting a drop in signal which they then lose final glide
> information. Several of our pilots had seriously intermittant GPS
> signals on Monday, May 16. Here is an explanation:
>
> http://www.navcen.uscg.gov/gps/gpsnotices and
> http://www.navcen.uscg.gov/gps/gpsnotices/GPS_Interference.pdf
>
> Usually the tests are from 8pm-4am on most days for us here in NM.
> They might only affect us on final glide on a good, long day.
>
>>From May 16-21, they are from 4pm-2am....this explains the trouble
> pilots had yesterday.
>
>>From 22 June to 02 July, they will take place from 3pm-1am.
>
> So, goe to the above site and check for your area, its possible your
> area will be affected even if its not listed. Thermal tight, Soar high,
> fly safe. # 711 reporting
>

May 28th 05, 05:30 PM
Folks, read the Web pages I posted when I started this thread. It
should answer almost all your questions, and then before you fly, make
a call, and check notams, etc. Thermal tight, Soar high, Fly safe. #
711.

May 28th 05, 11:01 PM
Has anyone checked with AOPA on this? If the cones of jamming are as
large as they post and the test last more than a minute or two, that
could be a real safety issue. I suspect though that they post many more
hours and days than needed.

Google