Eeek! GPS jamming........

mjf

mjf

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Just read a very interesting piece about some test Trinity House performed where a small jammer was used off a headland that was able to 'jam' the GPS rx on one of their craft 20nm distant. Seemingly bridge chaos occurred with alarms being activated, autopilot altering course, AIS info showing vessels at 1000Knots etc etc.

It seems that these units are small (like a mobile phone) and are used by car thieves who need to jam trackers......


Imagine a bloke standing on the White Cliffs above Dover and switching one on.


Accident waiting to happen IMHO.
 
Whilst worrying about things 20nm out to sea: a friend of a friend, test-firing on Challengers at Lulworth, once dispatched a fin round on a hesh elevation, allegedly. They reckoned it landed about 20nm out. :eek:
 
Different types of artillery shell. HESH is High Explosive Squash Head - a big heavy old lump that needs to be aimed high to get any distance. A fin round is an Armour-piercing, fin-stabilized, discarding-sabot (APFSDS) which is much lighter and would normally be fired on a much flatter trajectory...
 
He tells me that, if the incident happened at all, it was a Challenger I and that the incident was not logged. As there were no contemporary reports of French fishing vessels being sunk, they concluded that they must just have scored a direct hit on the sea.
 
mjf said:
Just read a very interesting piece about some test Trinity House performed where a small jammer was used off a headland that was able to 'jam' the GPS rx on one of their craft 20nm distant. . . . .
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I have recently done a lot of work in connection with AIS for Trinity House and I am not aware of this 'test'. :confused:

Please can you point me towards the document you have read?

I am aware of some GPS jamming which will take place 30 November to the 4 December this year out at sea between 7 and 13 nautical miles off South Shields. If on passage through this area during these dates, note that your GPS navigation equipment might (will) malfunction.
 
lenseman said:
I have recently done a lot of work in connection with AIS for Trinity House and I am not aware of this 'test'. :confused:

Please can you point me towards the document you have read?

I am aware of some GPS jamming which will take place 30 November to the 4 December this year out at sea between 7 and 13 nautical miles off South Shields. If on passage through this area during these dates, note that your GPS navigation equipment might (will) malfunction.
Click to expand...

Sounds like the Spadeadam ECM Military exercise area - all sorts of exotic things go on there.

Tom
 
nonitoo said:
Sounds like the Spadeadam ECM Military exercise area - all sorts of exotic things go on there.

Tom
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Spadeadam, where they play with ECM, is located some miles in land at:

55° 1′ 30″N, 02° 36′ 8″W.

http://en.wikipedia.org/wiki/RAF_Spadeadam


This exercise will be held out at sea off the east coast right on the two main ferry routes out of the east coast. On those days, I just hope it isn't foggy or an east coast Haar rolling in :rolleyes:

The location will be between these five co-ordinates:

55.150°N 01.142°W
55.000°N 01.008°W
54.967°N 01.167°W
55.017°N 01.217°W
55.133°N 01.217°W

SPLASH!! :eek:
 
GPS goes u/s, what's the big deal? They won't have painted the windows of boats black, nor stopped compass working, nor put blind folds on our eyes.
 
FRA, a company privatised from the RAF I understand, operate 4 or 5 Dassault Falcons from Teesside Airport for ECM sorties over the North Sea. You can see the ECM equipment on pods under the wings. Regular sight in the North East. Often see them in formation before they break to come into land.

Eddie
 
oceanfroggie said:
GPS goes u/s, what's the big deal? They won't have painted the windows of boats black, nor stopped compass working, nor put blind folds on our eyes.
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Agree - however the vessel that was 'affected' says there was chaos on the bridge.

AIS would alarm and Tx / Rx bad data, AIS radar display will alarm too. Plotter would alarm too. That said the auto pilot would still follow the gyro heading unless programmed to a waypoint so in that case the auto pilot would alarm too as bearing to waypoint would be up the wall etc etc. During this period a large helm order may well cause a vessel (s) to make large course alterations before the bridge team got their act together and cancelled alarms and normalized the vessel course, assertained correct position etc
 
mjf said:
Agree - however the vessel that was 'affected' says there was chaos on the bridge.
Click to expand...
But that's what professional officers are trained to deal with. I thought merchant vessels when on AP are locked on to a gyro compass heading, so loss of GPS not an issue for current heading lock, hence no uncommanded change of heading when signal lost. Thought waypoint or route tracking mode was not permitted as a best practice on AP for exactly these reasons.

Would be interesting to hear the "horses mouth" views from a number of serving deck officers.
 
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