GPS Outage?

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

Los Angeles Center (Palmdale CA) [ZLA]: September NOTAM #12 issued by
Gps Notam OA [GPS]
GPS is unreliable and May be unavailable within a 317 nautical
miles radius of 360056.3N/1173627.8W at FL400, decreasing in area with
decrease in altitude to a 267 nautical miles radius at FL250, 195
nautical miles radius at 10000 ft. mean sea level, and 186 nautical
miles radius at 4000 ft. above ground level. the impact area also
extends into the Mexican FIR 2000 - 0100 daily effective from
September 10th, 2007 at 01:00 PM PDT (0709102000) - September 15th,
2007 at 06:00 PM PDT (0709160100)

They're are up to it again, with our tax money.
My planned flight tomorrow may have the same problem, and it's
possible through Saturday. Last time they announced this, the GPS
blocking was hardly used, probably didn't work. Seems the jamming
system works now.
Jim

JS wrote:
Los Angeles Center (Palmdale CA) [ZLA]: September NOTAM #12 issued by
Gps Notam OA [GPS]
GPS is unreliable and May be unavailable within a 317 nautical
miles radius of 360056.3N/1173627.8W at FL400, decreasing in area with
decrease in altitude to a 267 nautical miles radius at FL250, 195
nautical miles radius at 10000 ft. mean sea level, and 186 nautical
miles radius at 4000 ft. above ground level. the impact area also
extends into the Mexican FIR 2000 - 0100 daily effective from
September 10th, 2007 at 01:00 PM PDT (0709102000) - September 15th,
2007 at 06:00 PM PDT (0709160100)

They're are up to it again, with our tax money.
My planned flight tomorrow may have the same problem, and it's
possible through Saturday. Last time they announced this, the GPS
blocking was hardly used, probably didn't work. Seems the jamming
system works now.
Jim

Jim

As I said on the phone, I'm going to re-register with DUATS. Thanks.

Paul

On Sep 11, 12:05 am, "P. Corbett " wrote:
JS wrote:
Los Angeles Center (Palmdale CA) [ZLA]: September NOTAM #12 issued by
Gps Notam OA [GPS]
GPS is unreliable and May be unavailable within a 317 nautical
miles radius of 360056.3N/1173627.8W at FL400, decreasing in area with
decrease in altitude to a 267 nautical miles radius at FL250, 195
nautical miles radius at 10000 ft. mean sea level, and 186 nautical
miles radius at 4000 ft. above ground level. the impact area also
extends into the Mexican FIR 2000 - 0100 daily effective from
September 10th, 2007 at 01:00 PM PDT (0709102000) - September 15th,
2007 at 06:00 PM PDT (0709160100)

They're are up to it again, with our tax money.
My planned flight tomorrow may have the same problem, and it's
possible through Saturday. Last time they announced this, the GPS
blocking was hardly used, probably didn't work. Seems the jamming
system works now.
Jim

Jim

As I said on the phone, I'm going to re-register with DUATS. Thanks.

Paul

there are often NOTAMs issued for areas of known GPS outagaes

P. Corbett wrote:

As I said on the phone, I'm going to re-register with DUATS. Thanks.

If you are doing that to get NOTAMS, take a look at this FAA NOTAM site:

https://pilotweb.nas.faa.gov/distrib...TOKEN=89793005

It's the most useful I've found for NOTAMS, and I like it far more than
DUATS. I mostly use the Radius Search, since I usually don't know which
direction I'm going. A 100 nm radius produces a lengthy list, but I can
page through it quickly, because airport listing with NOTAMS are a
different color. Other NOTAMS are listed, in addition to the airport NOTAMS.

I haven't used DUATS for a several years, as I found I could get better
information, presented more usefully, from other places on the Internet.
I could never stop DUATS from giving me pages and pages of worthless
information. Now, give me Dr Jack, NWS weather for the local area,
satellite photos, FAA's NOTAM site, and the NIFC graphical TFR site, and
I'm good to go.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

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

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

Hi Paul,

I recall hearing about some higher power GPS testing that went on at
China Lake around that time period. It was for about 3-4 weeks, I
believe. The info came from the Military Operations Specialist (MOS)
at ZLA (Los Angeles) ARTCC where I listen in on the morning 8am stand
up briefings. GPS testing is frequently NOTAMed for China Lake and
other areas like White Sands. But, during this period, the testing was
for stronger jamming. The MOS mentioned that they should be contacted
by controllers receiving loss of GPS reports from pilots. She/he would
then have contacted the testers to turn it off.

Yes, there are schedules for the GPS testing in the NOTAMS. Don't know
if this higher power testing was mentioned, though, in the NOTAMS.

Walt Rogers
MIC Los Angeles Center Weather Service Unit... Palmdale, CA

On Oct 22, 9:21 pm, WaltWX wrote:
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.

Yes, there are schedules for the GPS testing in the NOTAMS. Don't know
if this higher power testing was mentioned, though, in the NOTAMS.


More reason to keep barographs and turnpoint cameras!!!

-Pete
#309

I use this schedule put out by the Coast Guard. The
China Lake times are from April thru Sept, mornings
and afternoons PDT.

http://www.navcen.uscg.gov/gps/gpsno...terference.pdf

Rick 'CL'

At 04:24 23 October 2007, Waltwx wrote:
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

Hi Paul,

I recall hearing about some higher power GPS testing
that went on at
China Lake around that time period. It was for about
3-4 weeks, I
believe. The info came from the Military Operations
Specialist (MOS)
at ZLA (Los Angeles) ARTCC where I listen in on the
morning 8am stand
up briefings. GPS testing is frequently NOTAMed for
China Lake and
other areas like White Sands. But, during this period,
the testing was
for stronger jamming. The MOS mentioned that they should
be contacted
by controllers receiving loss of GPS reports from pilots.
She/he would
then have contacted the testers to turn it off.

Yes, there are schedules for the GPS testing in the
NOTAMS. Don't know
if this higher power testing was mentioned, though,
in the NOTAMS.

Walt Rogers
MIC Los Angeles Center Weather Service Unit... Palmdale,
CA

I use this schedule put out by the Coast Guard. The
China Lake times are from April thru Sept, mornings
and afternoons PDT.

http://www.navcen.uscg.gov/gps/gpsno...terference.pdf

Rick 'CL'

At 04:24 23 October 2007, Waltwx wrote:
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

Hi Paul,

I recall hearing about some higher power GPS testing
that went on at
China Lake around that time period. It was for about
3-4 weeks, I
believe. The info came from the Military Operations
Specialist (MOS)
at ZLA (Los Angeles) ARTCC where I listen in on the
morning 8am stand
up briefings. GPS testing is frequently NOTAMed for
China Lake and
other areas like White Sands. But, during this period,
the testing was
for stronger jamming. The MOS mentioned that they should
be contacted
by controllers receiving loss of GPS reports from pilots.
She/he would
then have contacted the testers to turn it off.

Yes, there are schedules for the GPS testing in the
NOTAMS. Don't know
if this higher power testing was mentioned, though,
in the NOTAMS.

Walt Rogers
MIC Los Angeles Center Weather Service Unit... Palmdale,
CA