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bigfoot

Just got this in by email
The MoD has informed Ofcom of the following GPS jamming exercises:

Dates: 31 March to 4 April 2008
Times: between 08:00 and 18:00 hrs
Location: To sea from Bridlington - N54° 06.842’ W000° 05.045’
Contact: Trial Manager - 07766 134758

Dates: 20-21 April 2008 (26 April 2008 reserve day)
Times: between 09:00 and 17:00 hrs
Location: To sea from The Hebrides - N57° 14.4’ W007° 26.7’
Contact (during jamming exercise only) 07766 134520

gm6vxb

All part of a military excercise going on at the moment. Loads of jets playing out to sea near here. Causing chaos with offshore helicopter traffic and ATC in Aberdeen going grey !!.
Martin.

geraldandannie · Moderator

That's interesting. So do they jam the GPS signals so that they don't interfere with the comms equipment on board?

Gerald

DABurleigh

Gerald,

No. They are testing/training in navigation warfare. Google Navwar.

Dave

gm6vxb

Two ways that the GPS positioning can be screwed up.
1. Selective Dilution of Position (DOP) which moves your position relative to where you are. Only the controllers can do this. This used to be done but don't think it has been for a while. Easy to get round by using a Differential GPS (DGPS) which is a fixed accurate point that transmits a data offset to a receiver conected to your GPS. Several lighthouses round the country still transmit this data. Used to play with this years ago for high accuracy positioning.
2. Localized jamming. Much more fun. The frequencies used mean it can be quite localized so one minute you know where you are, then suddenly !!!!!.

Won't affect normal users unless you happen to be near the locations mentioned, but in a motorhome !!!!.