GPS Jamming Exercise at Portreath
Thread Starter
Ecce Homo! Loquitur...
Joined: Jul 2000
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From: Peripatetic
GPS Jamming Exercise at Portreath
Just hope the Navy don't get lost....... 
BBC: MoD set to block sat nav systems
People in Cornwall have been warned satellite navigation systems will not work later this week as the Ministry of Defence carry out a jamming exercise.
The aim of the GPS blocking exercise is to find out how interference could affect military personnel. It will take place on Thursday and Friday. The MoD said its Portreath base would be the base. The effect will extend for a radius of 11 km (7 miles) which would cover Camborne and Redruth.
"Although GPS provides highly accurate information, the radio signals from the satellite are extremely weak and are susceptible to both jamming and unintentional radio interference," said the MOD in a statement. "The trials are taking place to better understand these effects on military equipment and therefore will help to protect our forces."
An MOD spokesman said all the emergency services which might use the systems have been informed and if an emergency is under way, the MOD can suspend the trial.
All ambulances are fitted with satellite navigation and in a statement, South Western ambulance service said it was aware of the jamming exercise and that key staff had been informed. Falmouth Coastguard said it had also been told.
BBC: MoD set to block sat nav systems
People in Cornwall have been warned satellite navigation systems will not work later this week as the Ministry of Defence carry out a jamming exercise.
The aim of the GPS blocking exercise is to find out how interference could affect military personnel. It will take place on Thursday and Friday. The MoD said its Portreath base would be the base. The effect will extend for a radius of 11 km (7 miles) which would cover Camborne and Redruth.
"Although GPS provides highly accurate information, the radio signals from the satellite are extremely weak and are susceptible to both jamming and unintentional radio interference," said the MOD in a statement. "The trials are taking place to better understand these effects on military equipment and therefore will help to protect our forces."
An MOD spokesman said all the emergency services which might use the systems have been informed and if an emergency is under way, the MOD can suspend the trial.
All ambulances are fitted with satellite navigation and in a statement, South Western ambulance service said it was aware of the jamming exercise and that key staff had been informed. Falmouth Coastguard said it had also been told.
Joined: Apr 2007
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From: South of the ex-North Devon flying club. North of Isca.
Yimp,
How can it be a beadwindow occurance when he is quoting from open source and public information given out by MoD to the locals round said airfield as to why their GPS won't work for a few days next week?
http://news.bbc.co.uk/1/hi/england/cornwall/6719639.stm
Foot, Mouth, .......
How can it be a beadwindow occurance when he is quoting from open source and public information given out by MoD to the locals round said airfield as to why their GPS won't work for a few days next week?
http://news.bbc.co.uk/1/hi/england/cornwall/6719639.stm
Foot, Mouth, .......
Joined: Sep 2002
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From: Pfffft
As per the NOTAM;
AUS 07-06-0207/1706/AS2 GPS SIGNAL JAMMING TRIALS. GND JAMMER LOCATED WI 0.5 NM OF 5016N 00516W (PORTREATH, CORNWALL). ACTIVITY MAY AFFECT ACFT WI 6NM RADIUS FLYING BELOW FL300...
They ran a similar trial out of Sennybridge very recently, also well NOTAM'ed. Nothing untoward was noticed at all during the notified period even when flying well within the reported radiating area.
AUS 07-06-0207/1706/AS2 GPS SIGNAL JAMMING TRIALS. GND JAMMER LOCATED WI 0.5 NM OF 5016N 00516W (PORTREATH, CORNWALL). ACTIVITY MAY AFFECT ACFT WI 6NM RADIUS FLYING BELOW FL300...
They ran a similar trial out of Sennybridge very recently, also well NOTAM'ed. Nothing untoward was noticed at all during the notified period even when flying well within the reported radiating area.
Joined: Mar 2005
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From: Falmouth
How does the MOD stand on a legal point if for instance someone who has paid a lot of money for his Tom Tom gets lost due to the GPS signal being jammed? Could argue the same point for a sailor in his Yacht getting lost.
Joined: Mar 2005
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From: Kammbronn
I might be tempted to get the sextant out of it's box.
Or stay close to the pub.
TBH, I don't think my Cornish rellies will be much affected - they're still struggling with the concept of a dual-carriageway A30.
Or stay close to the pub.
TBH, I don't think my Cornish rellies will be much affected - they're still struggling with the concept of a dual-carriageway A30.
Last edited by diginagain; 5th June 2007 at 13:28.
Red On, Green On
Joined: May 2004
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From: Between the woods and the water
How does the MOD stand on a legal point if for instance someone who has paid a lot of money for his Tom Tom gets lost due to the GPS signal being jammed?
Joined: Jul 2006
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From: .....................................
From the user manual. GPS is operated and controlled under the sole responsibility of the Government of the United States of America, who are responsible for its availability and accuracy. So if they don't stop the UK from jamming it then it's all their fault.
Red On, Green On
Joined: May 2004
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From: Between the woods and the water
how exactly do you effectively stop someone jamming a GPS signal?
.
Joined: Aug 2006
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From: firmly on dry land
As the GPS receiver is very sensitive and uses only very weak signals a jamming signal does not have to be very powerful. Low powered transmitters could be very small and easy to hide, even from a 2000lb bomb.
Indeed several in an area could cause a GPS jammer-homing bomb to land in a 'safe' area.
Joined: Aug 2005
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From: Tennessee - Smoky Mountains
Call me old fashioned, if you will, but the first defence to jamming is to change frequency. It would not surprise me if the GPS network had a frequency agility mode.
Second defence is to not use fixed frequencies at all, and to frequency hop. GSM phones have the capability to do this at 217Hz. Thus the effect of a jammed/interfered-with channel is averaged over the other time slices, and is negligible. Forward error correction is also applied, in order to be able to reconstruct the lost data.
Better still is to use a CDMA system, where the transmit bandwidth is so wide, and the amplitude so low, that the signal appears as noise to the adjacent channels.
Failing that, MLRS does a good job of anti-jamming.
Second defence is to not use fixed frequencies at all, and to frequency hop. GSM phones have the capability to do this at 217Hz. Thus the effect of a jammed/interfered-with channel is averaged over the other time slices, and is negligible. Forward error correction is also applied, in order to be able to reconstruct the lost data.
Better still is to use a CDMA system, where the transmit bandwidth is so wide, and the amplitude so low, that the signal appears as noise to the adjacent channels.
Failing that, MLRS does a good job of anti-jamming.
