First hand experience with GPS Jamming

Got my first experience with GPS Jamming. Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today.
I would go from 8 satellites showing on my GPS Nav Display (Cambridge
Model 20 GPS) to none, lost distance to turnpoint, lost ground track,
lost bearing to turnpoint in the blink of an eye. Typically, after a
minute or two, the GPS Nav would resume navigation with three
satellites showing. It would in rather short order (10-15 seconds)
get back up to tracking 8 satellites. Repeat process in 2-5 minutes.

I am assuming this was GPS jamming, as nobody else flying from
Sunflower reported any sort of issues, and it only happened in this
one stretch along I-35. Interestingly enough, it happend only once (I
think ) after I crossed to the east side or I-35. Maybe I was just
far enough from the jammers.

My flight is uploaded to OLC. If you download it and watch it in any
playback, you will see me stop, then jump forward. This particular
GPS has worked perfectly before and since. It was only this one brief
section of one leg of the flight. Of course, it really gets your
attention when your display goes all dashes, and the computer says
"GPS Wait".

Anyone else had an "encounter" like this?

Just curious

Steve Leonard
Nimbus 3 VJS

On Jul 23, 10:37*pm, Steve Leonard wrote:
Got my first experience with GPS Jamming. *Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today.
I would go from 8 satellites showing on my GPS Nav Display (Cambridge
Model 20 GPS) to none, lost distance to turnpoint, lost ground track,
lost bearing to turnpoint in the blink of an eye. *Typically, after a
minute or two, the GPS Nav would resume navigation with three
satellites showing. *It would in rather short order (10-15 seconds)
get back up to tracking 8 satellites. *Repeat process in 2-5 minutes.

I am assuming this was GPS jamming, as nobody else flying from
Sunflower reported any sort of issues, and it only happened in this
one stretch along I-35. *Interestingly enough, it happend only once (I
think ) after I crossed to the east side or I-35. *Maybe I was just
far enough from the jammers.

My flight is uploaded to OLC. *If you download it and watch it in any
playback, you will see me stop, then jump forward. *This particular
GPS has worked perfectly before and since. *It was only this one brief
section of one leg of the flight. *Of course, it really gets your
attention when your display goes all dashes, and the computer says
"GPS Wait".

Anyone else had an "encounter" like this?

Just curious

Steve Leonard
Nimbus 3 VJS

Yes, about two weeks ago, flying from Moriarty. Some of the same
thing you described, plus vertical climbs that would delay and show
vertical movement without circling. I was thinking it was military
jamming or problems under thick water laden clouds.
http://www.onlinecontest.org/olc-2.0...htId=211956832

Mike Carris

"Got my first experience with GPS Jamming. Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today".

What kind of equipment do you think these truckers were using to jam
with?

On Jul 24, 11:57*am, glidergeek wrote:
"Got my first experience with GPS Jamming. *Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today".

What kind of equipment do you think these truckers were using to jam
with?

Cheap. Google....

I've seen intermittent loss of GPS signal at low altitude twice this
Summer... now I know why. In both cases I was very close to a
highway.

Things that make you go "grrrrrrrrrrr."

-Evan Ludeman / T8

On Jul 24, 12:44*pm, Greg Arnold wrote:
On 7/24/2011 11:29 AM, T wrote:









On Jul 24, 9:12 am, *wrote:
On Jul 24, 11:57 am, *wrote:

"Got my first experience with GPS Jamming. *Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today".

What kind of equipment do you think these truckers were using to jam
with?

Cheap. *Google....

I've seen intermittent loss of GPS signal at low altitude twice this
Summer... now I know why. *In both cases I was very close to a
highway.

Things that make you go "grrrrrrrrrrr."

-Evan Ludeman / T8

I know of no equipment carried by truckers that jam GPS. The FCC and
others would be very interested.
T

Why would truckers want to jam GPS? *Also, I did a Google search, and I
only see jammers that work within 30 feet.

From "The Economist":

"Such devices are illegal to sell or use, but they have become popular
with commercial drivers who object to their employers tracking their
every move. A jammer prevents a tracking device in the vehicle from
determining (and then reporting) its location and speed—but it also
disrupts GPS signals for others nearby."

On 7/24/2011 1:12 PM, Bill D wrote:
On Jul 24, 12:44 pm, Greg wrote:
On 7/24/2011 11:29 AM, T wrote:









On Jul 24, 9:12 am, wrote:
On Jul 24, 11:57 am, wrote:

"Got my first experience with GPS Jamming. Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today".

What kind of equipment do you think these truckers were using to jam
with?

Cheap. Google....

I've seen intermittent loss of GPS signal at low altitude twice this
Summer... now I know why. In both cases I was very close to a
highway.

Things that make you go "grrrrrrrrrrr."

-Evan Ludeman / T8

I know of no equipment carried by truckers that jam GPS. The FCC and
others would be very interested.
T

Why would truckers want to jam GPS? Also, I did a Google search, and I
only see jammers that work within 30 feet.

From "The Economist":

"Such devices are illegal to sell or use, but they have become popular
with commercial drivers who object to their employers tracking their
every move. A jammer prevents a tracking device in the vehicle from
determining (and then reporting) its location and speed—but it also
disrupts GPS signals for others nearby."


The employers go to the expense of installing GPS devices, but they
don't mind that their drivers are disrupting the GPS signals? Doesn't
make much sense.

On 7/24/2011 2:20 PM, Greg Arnold wrote:
On 7/24/2011 1:12 PM, Bill D wrote:
On Jul 24, 12:44 pm, Greg wrote:
On 7/24/2011 11:29 AM, T wrote:









On Jul 24, 9:12 am, wrote:
On Jul 24, 11:57 am, wrote:

"Got my first experience with GPS Jamming. Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today".

What kind of equipment do you think these truckers were using to jam
with?

Cheap. Google....

I've seen intermittent loss of GPS signal at low altitude twice this
Summer... now I know why. In both cases I was very close to a
highway.

Things that make you go "grrrrrrrrrrr."

-Evan Ludeman / T8

I know of no equipment carried by truckers that jam GPS. The FCC and
others would be very interested.
T

Why would truckers want to jam GPS? Also, I did a Google search, and I
only see jammers that work within 30 feet.

From "The Economist":

"Such devices are illegal to sell or use, but they have become popular
with commercial drivers who object to their employers tracking their
every move. A jammer prevents a tracking device in the vehicle from
determining (and then reporting) its location and speed—but it also
disrupts GPS signals for others nearby."


The employers go to the expense of installing GPS devices, but they don't mind
that their drivers are disrupting the GPS signals? Doesn't make much sense.

Hmmm...re-ask your question again after you've queried a few employers to get
their takes on things (helpful hint: Werner Trucking), then report back to the
group.

Thanks!

Bob W.

P.S. Just to stay on topic, I predict all will be 'soar.'

On Jul 24, 1:12*pm, Bill D wrote:
On Jul 24, 12:44*pm, Greg Arnold wrote:





On 7/24/2011 11:29 AM, T wrote:

On Jul 24, 9:12 am, *wrote:
On Jul 24, 11:57 am, *wrote:

"Got my first experience with GPS Jamming. *Apparently, lots of
truckers on I-35 near the Kansas-Oklahoma border were jamming today".

What kind of equipment do you think these truckers were using to jam
with?

Cheap. *Google....

I've seen intermittent loss of GPS signal at low altitude twice this
Summer... now I know why. *In both cases I was very close to a
highway.

Things that make you go "grrrrrrrrrrr."

-Evan Ludeman / T8

I know of no equipment carried by truckers that jam GPS. The FCC and
others would be very interested.
T

Why would truckers want to jam GPS? *Also, I did a Google search, and I
only see jammers that work within 30 feet.

From "The Economist":

"Such devices are illegal to sell or use, but they have become popular
with commercial drivers who object to their employers tracking their
every move. A jammer prevents a tracking device in the vehicle from
determining (and then reporting) its location and speed—but it also
disrupts GPS signals for others nearby."- Hide quoted text -

- Show quoted text -

I understand why the truckers would want to do this, more $$ in pocket
ultimately, but I don't understand why the FCC and Trucking Companies
would not do anything to stop it's use.
GPS receivers operate very, very close to the natural noise threshold
of their radio spectrum and are therefore very, very sensitive to
interference, could easily be 1/4th mile for an airborne receiver.
Enforcement is always a big problem so all we can do is stay away from
major hiways while flying.

I once lost a $500 model airplane to a trucker's 1KW CB rig when I
flew over him. In general they are unaware of the problems they create
with their Creative Fixes!

On 7-24-2011 20:33, Free Flight 107 wrote:


I once lost a $500 model airplane to a trucker's 1KW CB rig when I
flew over him. In general they are unaware of the problems they create
with their Creative Fixes!

Are you sure he was an illegal CBer running a KW or could he have been a
ham, legally running a KW? There are many truck drivers who are ham
radio operators. I drive a lot in my job, but generally run no more
that 150W while mobile...on frequencies from 1.8 MHz to 432 MHz. I have
gear for higher bands, but don't run them while mobile.

On 7/24/2011 8:05 PM, ray conlon wrote:
On Jul 24, 10:45 pm, wrote:
And the new 4G cellphone- GPS
interference battle is just beginning. The cell phone industry is
promising to deliver billions to the federal coffers, and the FAA cost
the feds $$$, who do you think will win that one?

I'm betting the cell phone people lose this one - it's not just the FAA
that uses GPS and intends to depend heavily upon for ADB-S, but the
airliners filled with nervous passengers (aka "taxpayers"), but many
businesses and about a jillion consumers (aka "taxpayers").

At least the problem is not wide spread at the moment. I've never
experienced a GPS problem while flying or driving (except for tunnels
and tall buildings!).

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)