back to article Could pen-sized GPS jammers paralyse UK shipping?

Contractors and sector-straddling quangocrats sought yesterday to convince politicians of the need to spend defence or security funds on radio-based backups for GPS satnav, according to reports. The BBC, covering recent Commons defence committee testimony, gives serious play to the contention by VT Communications and Trinity …


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  1. Anonymous Coward
    Black Helicopters

    Bullshitting and Scaremongering to get a budget?

    Say it isn't so...

    However, I do think that all UK high-streets should have mandatory GPS disabling pens all-round - Would make drivers actually open their eyes and watch where the Fuck they're going instead of driving blind.

  2. Jerry

    Synthesis Technology?

    Given GPS uses atomic clocks from multiple satellite transmitters to fix location on a metre scale, couldn't the same technology be back-fitted into the marine navigation systems?

    In the end it's all about time / phase from a known source. With GPS that is satellites with atomic clocks and a published ephemeris. If you used existing terrestrial transmitters (LORAN etc) with atomic clocks you wouldn't need an ephemeris. The transmitters are pretty fixed after all and they have access an awful lot more power than any solar powered satellite.

    Asides from the odd propagation anomaly, the earth based transmitters could do positioning to GPS accuracy at a fraction of the cost of satellites.

  3. E_Nigma


    Sorry about going offtopic, I skimmed through the "Mindprobing" article you linked to which says: "New Scientist reports that this is already done by specially-trained human screeners, but that's too manpower-intensive and time consuming for widespread use."

    That's not new at all, and it's done outside of the US too. Years ago, an elderly lady (my English professor) told me how she was taken aside on an international airport and questioned because, as she found out, it was noticed by the specialized staff that she was "too excited". And no, she didn't have any explosive devices or drugs, she was just visiting her sister who lived abroad.

  4. dervheid
    Black Helicopters

    Bullshitting & Scaremongering...

    is how anything wants to get done that might be;

    Expensive. or

    Controversial. or

    Of questionable 'benefit' to the nation. (ie 42 days detention without charge)

    So no change there then.

  5. Vladimir Plouzhnikov

    False economy

    The use of LORAN-C in aviation is actually increasing. Also LORAN-C provides reference time signals for telephone and data networks including the Internet. It's cheap to run and reliable. To turn it off would be a false economy.

    But then again, false economy is this Govt's speciality, so no big surprises here.

  6. Roy Stilling

    @ "trusty sextant as of old"

    But do mariners still get taught hwo to use them? I recall reading that the US Navy had decided to stop teaching its officer cadets such techniques on the grounds that GPS is ubiquitous. I'd love to believe that our dear old Senior Service wouldn't be so stupid as to follow suit, but seeing as the RN thought that the USN's Windows for Warships was a jolly good wheeze I'm not so sure.

  7. Anonymous Coward
    Anonymous Coward

    Can no-one see the danger ? !!

    Even Loran could theoretically be spoofed.

    I've got this Idea......

    Build big coastal towers at harbours and areas of danger. Then put a big light in the top that cycles on/off at known periods. It's so simple and totally un-jammable by terrorists !

    Can I have some money please?

  8. Chris Green

    Radar Can Fail - Well, it used to be able to!

    Things may be better now (I hope), but 30 years ago I did a daily crossing of the Solent on the hovercraft service between Cowes & Soton.

    On an especially foggy morning (fog=still=calm=faster), the pilot did an emergency stop as a large tanker loomed out of the fog in front of us. We missed it, but got very close. I was behind the radar seat and the operator just looked blank and showed me and a mate, a view of the solent with no tanker ahead!

    BTW, a hovercraft emergency stop is huge fun...deflate front skirt, dip nose into briny and watch the water shoot up the front. You stop real fast, believe me.

  9. david wilson

    @Vladimir Plouzhnikov

    >>"The use of LORAN-C in aviation is actually increasing. Also LORAN-C provides reference time signals for telephone and data networks including the Internet. It's cheap to run and reliable."

    So if it's cheap to run and useful, the users should presumably be happy to pay for it?

  10. Anonymous Coward
    Anonymous Coward


    Slightly missing the point - yes 1940's LORAN was rubbish, but what the GLAs and the USCG are pushing is eLORAN - modernized LORAN that brings updated transmitter & timing technology together with modernised receiver design ("All-in-view", now masses of DSP power, clever antenna tricks) - numerous tests and trials have shown that eLORAN can give comparable accuracy to GPS. eLORAN even has a data-channel, meaning UTC and integrity/augmentation broadcasts too.

    As an augmentation/backup to GPS, eLORAN's about as good as it gets!

    The problem eLORAN has is an image problem - it needs a re-branding! Everyone remembers the performance and other issues that LORAN-C has/had. Adding the little "e" to the from of the word isn't enough; it gets lost - as the BBC so ably demonstrated.

    Check out reelektronika and Crossrate for modernised receivers and the ILA's website for eLORAN evangelism.

  11. Mark

    @ Roy

    Don't worry Roy, the Senior Service still teaches people to shoot the stars. The US do (or did up to a few years ago) still shot the stars once a day on carriers.

  12. Anonymous Coward
    Anonymous Coward


    There's a couple of flaws with your plan there...

    Firstly, the number of transmitters would need to be a lot higher to cover anywhere near a sensible amount of area. A satellite is visible to (theoretically) just under 50% of the surface of the earth at any time, as opposed to 100 miles or so.

    Secondly, the number of atomic clocks you required would go through the roof as well - and they aren't cheap.

    Now, I know that's really one flaw, but I thought it was important enough to mention twice.

    (Apologies to all Red Dward fans for misquoting Kryten).

    Another (almost real) problem would be that you're forcing the ships to carry additional hardware solely to use the UK shipping areas. If every country did that, then half a super tanker would be required for navigation equipment. There's existing systems that (seem to) do the job fine - lets use them instead shall we?

  13. Carl

    jamming GPS

    Jamming civilian GPS may be easy, but jamming military GPS (P-code) is bloody hard. The people who designed the system did actually consider that it might be jammed. One of the advantages of the signal being below the background noise (you can filter the noise because you know the pseudorandom code you're looking for) is that broadband noise jamming has no effect. And what with steerable null-point antennae, Kalman filtering, etc...

  14. Anonymous Coward
    Black Helicopters

    GLA = Global Liberation Army

    I'm sure the GLA was the Global Liberation Army from C&C Generals... ...

  15. Anonymous Coward

    @Mark-t . A wise man once said

    For every measure there is a counter-measure,

    For every counter-measure there is an evasion,

    and so on 'til penetration

    That'll be a well aimed RPG.

  16. Dave_H
    Thumb Down

    LORAN = real pain

    I’m a member of a UK Cave Rescue Organisation, and we have to use low frequency communications to penetrate through the rock to rescue teams underground. The “galloping horses” interference from LORAN seriously degrades clarity of message reception and is very tiring for an operator to have to listen to. The sooner LORAN goes the better!

  17. Anonymous Coward

    forget eLoran, you need...

    to rename it to iLoran, and then it'll sell like i-hotcakes.

    Anyway, who's going to be first to comment on the commercial connections between BAe Systems and VT Comms? Is it going to be me?

  18. John Sturdy


    Even a big light on a tower that cycles on/off at known periods could theoretically be spoofed, using another big light that cycles on/off at the same periods (perhaps mounted on a cherry-picker for quick set-up and getaway). In fact, in an earlier form, it was an old wreckers' technique. And it's probably easier to design than a GPS jammer!

  19. Adam Foxton
    Thumb Up

    Lighthouses and Ter'rists and Bombs, oh my!


    The problem with ground-based stations is one of line-of-sight. As well as the "probability it'll get hit by an RPG or car bomb" factor. Not to mention if there was a power-cut. You'd have half of the UK's GPS-navigated drivers ploughing headlong through pedestrianised areas and walls because their GPS hadn't told them to turn...

    Orbital global positioning is the way to go. It's resiliant to attack, reliable (as they don't want to have to send another satellite up there!), and relatively simple to decode. Plus it's free to use and has all sorts of extra uses (New Scientist not too long ago had a short article about someone using the transmissions from the GPS satellites to find water)

    Also, DGPS receivers (Which would be similar to what you're proposing) are a little too big compared to the tiny chewing-gum-packet sized GPS devices available today. Check out ARQuake from the Uni of South Australia Wearables Lab- that's DGPS based.

    Finally, signals coming down the way are far better in urban environments than signals going sideways through buildings or relying on signal diffraction around buildings to provide signals to areas behind large buildings. Either that or the power rating would be high enough to cook birds and the occasional light aircraft...


    Lighthouses would be great unless the terrorists were armed with easily concealable spray paint. You can just imagine the headlines- "spray paint banned!" "Giving your car a new paint job- OF DEATH" "Paintball guns: The silent killer. Also they give out CO2 with every shot hence are evil."

    eLORAN sounds like it's a good investment. Though it does need a better name- perhaps LORANe (as in Lorraine)? Nerds like techs with womens names so that should give it a better chance of succeeding!

  20. Liam Johnson


    >>Adding the little "e" to the from of the word isn't enough;

    How about iLoren???

  21. Dodgy Geezer Silver badge

    Sounds about right...

    "The US do (or did up to a few years ago) still shot the stars once a day on carriers..."

    Yup, makes sense. I've heard that the US Military shoot at anything they can see moving.....

    Mine's the one with the pearl-handled revolvers, shotgun and Anti-Tank rifle in the back pocket...

  22. Joe Harrison

    @Mark_T No money for you

    Sadly your idea of unjammable coastal light towers can be attacked through its "people with lanterns" vulnerability (see "Jamaica Inn" by security researcher Daphne DuMaurier.)

    Presumably the DGPS service is now defunct and its purveyors had a good rant at Clinton then forgot about it and moved on to something else. Why shouldn't these Loran people follow the same plan?

  23. Vladimir Plouzhnikov

    @david wilson

    I don't know the exact numbers but the US spends something like USD 20 - 30 million per annum to maintain their LORAN-C coverage. What can the cost be here in the UK? A third of that? A quarter? I mean the real cost, not counting any corruption or pork attached.

    About paying for it - it's difficult to workout a per-use fee for a system like that. You don't pay for every VOR DME you fly over and, anyway, how would you know which ones your pilot was using, if any?

  24. Glen Turner

    Network timebases don't need LORAN (but we'll use it if it's there)

    "Also LORAN-C provides reference time signals for telephone and data networks including the Internet."

    Um, not really anymore. There's kit which uses LORAN-C as a timebase for network synchronisation. But that can readily be upgraded to use GPS. Which it is anyway when the maintenance of the LORAN-C timebases becomes more costly than replacing them with GPS.

    The "pen sized jammer" argument doesn't fly for network synchronisation from GPS. Firstly, the GPS is used to discipline a oscillator that will accurately run undisciplined for a few weeks. Secondly, the GPS antenna is typically on a tall roof or on a tower, as GPS accuracy increases a lot when there is more vision of the sky. Getting the jammer into position within the exchange building implies either poor physical security (which is usually self-correcting, as that results in expensive equipment is being knocked off) or an inside job (in which case you've got a lot more to worry about). Thirdly, there's usually four GPS receivers in various locations forming the timebase.

    As long as LORAN signals are transmitted then telcos will use them for disciplining timebases -- you want as many reliable independent disciplining signals as you can readily get hold of. But that's no justification for retaining the LORAN system, especially as it lacks global coverage. If we feel the need for additional timebase integrity that can always be arranged some other way.

    In fact if LORAN is only retained for providing network timebases then it loses a lot of value to us. One of the good points of GPS is that it is both maintained by the USAF and used by them for navigation and weapons systems. Thus the USAF has a strong interest in the accuracy and integrity of the GPS signal at all times. An almost-retired LORAN system would not have the same assurance, would have diminishing coverage over the years, etc.

  25. Steve Mann

    @ Roy Stilling

    I'm with you Roy, but the sextant is of no real use without a really accurate chronometer and some good-quality charts.

    Luckily, mosty handheld GPS sets have a clock and a map display.


  26. Ian Michael Gumby
    Thumb Up

    LORAN-C makes perfect sense.

    Mind you that GPS is probably the best way to get an accurate fix. GPS in survey work can be as accurate as a couple of cm. (You need to set up a base station and let it set for a while... ~48 hours or so)

    But for the bigger picture. What happens if there's a huge solar flare and you knock out a chunk of your GPS sats?

    LORAN-C is a cost effective viable alternative for navigation services.

    Sure it won't help you navigate within a port, however it will *get* you to the port.

    No fear mongering or FUD here.

    e-LORAN as the next generation? Maybe. But lets face it. When you have a ship that's 100m long, knowing your position within 200m is accurate enough to get you where you are going.


  27. Anonymous Coward
    Anonymous Coward


    Always ludicrously technical isn't it?

    Surely they'd just drive up to the ship in a dinghy while it's in the tricky narrow bit of the harbour (always one, trust me) and blow it up?

  28. Lukin Brewer

    Decca trashing

    Back in the late 80s, my physics lecturer, a keen weekend mariner, explained the Decca navigation system to my physics class as part of the telecommunications module that he was teaching. While a nice chap, he wasn't the sort to let faults in a system go unremarked. As far as he was concerned, Decca allowed him to obtain accurate bearings (sufficient for his needs) at any time of day and under any conditions, using what was basically an FM radio with a directional antenna and a built-in compass. He knew all about the the satnav of the time, but couldn't afford it.

    I can appreciate that if you're piloting a warship, you wouldn't want to go looking on *that* frequency for the station producing *that* beep pattern and then get a bearing from it, especially when there's another device available that will give you map coordinates. And, thinking about it, why would the authorities even think about the existence, let alone the needs, of weekend mariners (unless we have to pull off another Dunkirk). And GPS *has* made Decca redundant. However, the fact remains that for one group of happy amateurs, doing non-productive things on the seas around Britain, Decca did represent a rather useful bit of kit.

  29. Dave Bell

    Does anybody still make Chronometers?

    Mind you, a good digital watch is probably good enough, though what really matters is a stable error rate. Lose ten seconds a day, every day, and you can allow for it.

    (Secondary note: a bog standard railroad watch would be accurate enough for a 1930s Pan-Am Clipper on the trans-Pacific run. The error over the flight time is still less than the error in sextant readings from an aircraft.)

  30. StopthePropaganda
    Thumb Up

    as a military man...

    wouldn't you agree that two different technologies, with two greatly different modes of operation (and thusly two completely different methodologies to influence them) is the better way to go, Mr. Page? The idea of having all one's eggs (literally and figuratively) in one basket, whether it be GPS or Galileo, scares the living bejeezus out of me. For civilian use having the two separate systems is a great idea and gives choices and backup capabilities. In wartime or under any external threat, having two separate, hard to defeat navigational systems makes sense.

    Better to spend a few million pounds on maintaining your LORAN for another decade, than doling that much out each and every year to chavs pumping out more uneducated children and to illegal "immigrants" who's only concern is the overthrow of that system which pays their bills.

  31. Vladimir Plouzhnikov

    @Glen Turner

    The point I am trying to make is that "it's there already, it's useful and it doesn't cost much to maintain".

    If you retire it now you will save the maintenance costs minus the cost of dismantling, scrapping and area regeneration but you will also trigger an equipment and procedure upgrade in more than one industry AND lose a workable fall-back system for more than just maritime navigation.

    That does not seem like a good trade off to me - hence the false economy.

    I was not trying to say that LORAN should be used exclusively and replace GPS or something like that...

  32. Toby Brown
    Thumb Up

    great article

    Brill to read a more in depth article, by someone who knows what they're talking about!


  33. D

    I want one of those pens

    so I can while away my lunch hours sat outside a cafe, drink in hand watching the chaos that ensues.

  34. Anonymous Coward

    Decca was EASY

    Hang on there! Using the Decca radio navigation system was easy ; any competent navigating officer found it simple to use. I also think that you have got your LORANs crossed ; the proposal is to use eLORAN which gives a much higher accuracy and reliability than the earlier LORAN A and LORAN C systems.

    Regretfully, a backup to GPS is much needed as the continuing drive to lower costs in the shipping industry and provide consumers with cheaper socks, cars, bananas etc ( you name it) means that many of the poorly trained and poorly paid navigators of today place full trust in what their GPS is telling them and do not look out of the window.

    Mike (British Merchant Navy Officer and expert sandwich eater).

  35. Anonymous Coward


    For us Yanks, "loran" is the singular form of "lorries," correct?

  36. ian

    NaN - Not a Navigator

    While I'm not a navigator, and only use GPS rarely and in a safe manner, I do wonder if LORAN and Decca couldn't be upgraded in a way that would make them compatible with existing kit.

    And yes, I agree that multiple redundancy for something as important as navigation is important, certainly now that the Chinese have shown themselves willing and able to bash satellites.

  37. heystoopid

    Very Interesting

    "Very Interesting" to paraphrase on old catch phrase from a very old US Comedy TV Show of a past century , for it has arrived just in time in order to justify an evil act if passed will recreate an evil that was supposedly buried with it's creator last century at a very great cost indeed !

    Too many coincidences indeed and yet so very convenient for those who seek to be the evil emperors of the future claiming that it is in the public good to make it safe from the fears generated by these wowsers own self created paranoia !

    But then again in the late sixties , we we were truly warned about the coming of the incompetent ones .

    However the time has come to use the flamethrowers to burn this evil infestation out from behind their smokescreens and show their true evil characters to the world for what they really are !

  38. Rich

    Decca sets

    I suspect Lewis would have been using the standard mil-spec Naval sets, which produced lane based positions that you translated into your actual location using special overlaid charts. Yachtie and commercial Decca sets of the 80's and 90's had a lat/long readout, just like a satnav. Accurate to a few hundred meters - but it is possible to use differential correction (just like GPS) to improve on this - no point nowadays, I'd agree.

  39. James

    Common sense Vs. Sat Nav

    A jammer would be handy to place near the end of small country lanes that GPS devices like to lead people (or people like to be led by GPS), (on the same note don't follow a GPS on the shortest route to Alton Towers) causing problems both for residents and drivers:'damaging-ancient-buildings'.html,satnav-turns-drivers-into-kid-killers.aspx

    The list goes on. And all the occasions this happens and doesn't make the news.

  40. James

    Image of what Sat Nav users see

    Sorry but I had to illustrate my interpretation of what sat nav users see when driving:

  41. Aitor

    Radar & Fog

    Well, as someone pointed out, radar and fog make a bad mix.. some older radars can't detect ships if you are surrounded by fog, the obstacle is very close or another ship is near the coast and comes from that direction...

  42. TMS9900

    Is it me?

    If it *is* possible to disable GPS comms with a pen sized device (as opposed to a pen) I would have thought it would be quite easy to find the location from which the jamming signal is emanating, and switch it off, with, say a Harrier Jump Jet and Stinger missile?

  43. Kevin Dwyer
    Gates Halo


    Rule of thumb,

    If you see a headline which asks a question, don't even bother reading the article, the answer to the question posited is almost certainly "No"

    Bill, as he has realised the futility of being the wealthiest man in the Cemetary.

  44. Anonymous Coward
    Anonymous Coward

    @Joe Harrison

    "Presumably the DGPS service is now defunct "

    Not at all. The company I work for has its own DGPS system it rents out rather profitably to other companies as well as for its own internal use.

    When you're trying to lay pipe on the seabed in kilometers of water-depth and currents- and with yourself bobbing up and down as well- accurate positioning is everything. Standard GPS isn't anywhere near accurate enough.

  45. Mike Hocker

    Stinger missile

    More likely a HARM if you really want to nail that GPS jammer...

  46. Davy


    Such a Joy to get the Register headlines once a week-excellent articles like this(well done Lewis) and informed, articulate, sceptical, humourous top-quality comment ! I have stopped taking the Telegraph and ceased believing anything from the BBC years ago.

    Decca was accurate to within 20 metres in terms of repeatability; you could go back to the same mark (I'm a fisherman) and it would be there, although would probably not correspond to your correct position on the chart. Decca would "go off" with rain and darkness. In any event, evrybody threw out their Navstar 2000's years ago although I recently had the delight of uncovering an old Mark 12 in a workshop in Trondheim !

    There are other alternatives such as inertial guidance as used on Submarines and modern radars are usually excellent for both longer distance navigation and close up boat handling.

    But we should definitely maintain the old skills of sextant, chart, ephemeris and chronometer, the oil won't last forever and while we're at it what about the complicated sail evolutions of the square-rigger?

    I hope I live long enough.

    A quick broadside and board 'em in the smoke !

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