Paul:
Yes, there is a schedule.
The National Authorization NOTAM for GPS Jamming is issued each fall
for the following
calendar year. In the US jamming can happen in California, New Mexico
and St. Louis.
This year the web page didn't go up in a timely manner,
and I mailed my contact at China Lake to inquire.

It turns out that this year's "authorization" is for dawn to dark,
Monday to Friday, for 52 weeks.
http://www.navcen.uscg.gov/gps/gpsno...terference.pdf

Airliners nav around this airspace, so it isn't a big deal for them,
which is why most pilots have never heard of this. Ask the 1-26ers
about their
contest two(?) years ago that had to negotiate with White Sands to
alter the
jamming/spoofing times to not blank out a sanctioned contest. White
Sands
was very cooperative.


Since Region 12 Soaring Council holds a Letter of Agreement for wave
window access
here, that requires a regular contact point for the DoDefense to pass
out information
on what occurs in the R-2508 Complex. That comes to me, and has been
for a couple of
decades.

I get weekly emails from them advising what will happen for jamming/
testing
for the following week. This was important to us, particularly when
Steve Fossett
was launching from Cal City in pursuit of altitude work/records/
systems checking
three years ago. IGC politely rebuffed me, when I inquired to ask if
we could validate
record flights here with our "old" Winter 30 km barographs, to back up
the new improved
flight recorders. I was told that jamming just didn't happen. So I
later supplied
a flight trace that was interrupted and a pilot in NM had a White
Sands "spoofed"
redirected flight posted on OLC in the same period.

It turns out that the IGC wasn't interested in "backtracking" in
technology, despite
hard proof that there may be problems in a locale that has produced
and can produce
World Records on a recurring basis.

As a result, I watch the jamming schedules very closely.
They will be jamming here all week, during business hours,
intermittently.
Your logger is fine, and you can check it yourself by seeing that the
pressure
aneroid keeps right on graphing, while the flight track is absent.

If pilots are trying for records in SoCal, and want to be on a pass-
along schedule
list from their SSA Director, they should mail me that request
privately.

Cindy B
SSA Region 12 Director
Caracole Soaring



On Sep 10, 7:29 pm, "P. Corbett " wrote:
Today (Sept 10 2007), I experienced an intermittent GPS outage, about 50
NM southwest of China lake, CA. The longest duration was about 15
minutes. There were several shorter ones as well. I know that the Navy
at China Lake has announced that this can occur from time to time.

Does anyone know if there is a schedule for these? Are they logged so
after the fact, the public can tell if they were jamming and therefore
the GPS receiver is not at fault?

Paul
ZZ