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Intentional GPS Jamming On the Increase 243

Posted by timothy
from the can-you-find-me-now-can-you-find-me-now dept.
benst writes "Here's yet another way to measure the success of GPS: by the efforts to negate it. While unintentional jamming continues to rise, intentional jamming by both foreign military forces and at-home miscreants of various stripes has shown increased vigor in the past six months. Related here are recent instances of intentional jamming on each side of the border, and (briefly outlined) one initiative mounted by the National Geospatial Intelligence Agency (NGA) to counteract it. Also, here are some ways to detect and prevent jamming."
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Intentional GPS Jamming On the Increase

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  • by Thanshin (1188877) on Friday June 27, 2008 @04:50AM (#23964543)

    The best way of jamming the signals will soon be to down the satellite.

    How hard is to hit a satellite right now?

    What's the best method? Microwaves? Laser? Missile? Or my preferred method, Killer satellite robot.

    • by oodaloop (1229816) on Friday June 27, 2008 @04:56AM (#23964583)
      Shooting down a U.S. military satellite doesn't sound like a particularly well-thought out plan to me.
      • by Anonymous Coward on Friday June 27, 2008 @06:26AM (#23965103)

        After all, they deny lots of junk up there.

        Just shoot one of them down and see who complains and THEN you'll know whose it was.

      • by v1 (525388)

        well if they don't want to claim ownership/possession of it in the first place, that makes it harder for it it complain when it goes missing.

        "I'm sorry, you should have told us that was your satellite, we DID ask. We just assumed since nobody claimed it, it was just some random space junk."

    • Re: (Score:2, Insightful)

      Don't try and down the satellite... too much effort

      Just put loads of debris in the same orbit at a greatly different speed ... that should disable any satellite .... ... China did that by blowing up one of their own satellites ....

      • by kocsonya (141716) on Friday June 27, 2008 @06:05AM (#23964977)

        > Just put loads of debris in the same orbit at a greatly different speed

        Unfortunately, the same orbit means the same speed - different speeds, different orbits.
        You need to create an orbit that crosses the satellite's orbit at some point and wait until your debris and the satellite meet at the crossing (since their orbiting times are different, they will, if you wait long enough).

        • > Just put loads of debris in the same orbit at a greatly different speed

          Unfortunately, the same orbit means the same speed - different speeds, different orbits.
          You need to create an orbit that crosses the satellite's orbit at some point and wait until your debris and the satellite meet at the crossing (since their orbiting times are different, they will, if you wait long enough).

          Not if their orbital speeds are linearly dependent, which I think they will be if they are at the same altitude.

          Think of how much area the earth has at it's surface. Now think of how much area a sphere with the sat's altitude+Re as it's radius. Not very good odds for the debris to hit, you see.

    • by mbone (558574) on Friday June 27, 2008 @05:15AM (#23964705)

      Anyone with the capacity to down multiple satellites (losing one wouldn't do much) 20,200 kilometers above the surface of the Earth is not going to be posting about it on slashdot.

    • It's one thing hitting a LEO sat. It's quite another trying to hit a GPS satellite which is 26000 km up.
    • secret signals (Score:5, Insightful)

      by Quadraginta (902985) on Friday June 27, 2008 @05:37AM (#23964825)

      I would say the obvious solution to jamming is to have secret signals from the satellites. If you use spread-spectrum techniques your signals become more resistant to jamming. It's possible you might even make your signal nearly undetectable, so that your enemies don't even know it exists.

      This being a well-known technique in military radio communications, I would be a little surprised if (1) there weren't already "black" SS signals available to the military, or (2) there will be soon enough.

      They may not be especially worried about this. It's not like it's hard to detect someone jamming you, and if you're in a war situation a HARM missile can take care of them for you. Generally a big radio signal is a bit of a liability in a war zone. Makes you stand out, more or less like an electromagnetic bull's-eye painted on your chest.

      • Re: (Score:3, Informative)

        by greyblack (1148533)
        Joke?

        Check Wikipedia on GPS.

        GPS signals are currently using direct sequence spread spectrum signals to enable every sattelite to transmit on the same frequency. There are two signals, the "free-to-everyone" C/A code, and the military-only P-code (transmitted on two frequencies). The C/A code has a relatively short ss-word and the P-code has a very long ss-word, making it hard to jam...

        I would guess most of the jamming mentioned in TFA is aimed at commercial GPS receivers. Now if the Chinese make someth
        • by clodney (778910)

          The article discusses the Chinese jammer efforts as being worrisome to US military, specifically the 7th fleet.

          I assume that military kit like the JDAM bomb packages all use military receivers, so I think TFA does at least strongly imply that military receivers are being jammed.

          • Re: (Score:3, Informative)

            by afidel (530433)
            Hmm, I thought the inertial guidance was better on JDAM, but wiki says it's only accurate to ~30m with inertial guidance vs ~10m with GPS. That's the difference between hitting the room you want vs not hitting the building at all.
      • Re:secret signals (Score:5, Insightful)

        by Detritus (11846) on Friday June 27, 2008 @07:26AM (#23965543) Homepage
        GPS already uses direct-sequence spread spectrum. The military-only signal uses a cryptographically secure spreading code. Even that will not protect you from a wideband jammer with enough power. Any signal can be jammed with a sufficiently large/near transmitter. The military usually solves that problem with high explosives.
        • Re: (Score:3, Insightful)

          by thegameiam (671961)

          High explosives can be pretty convincing.

          This basically shows that all security, at some point, boils down to heavily armed people.

      • Re: (Score:3, Informative)

        by Anonymous Coward

        The GPS satellites already use spread-spectrum signals. Each satellite is given a unique Pseudo-random Noise (PRN) code (along with a Space Vehicle number). The PRN code allows each satellite to generate a unique code for the spread-spectrum signals. This both puts the signal below the noise floor and increases jamming difficulty. The civil code generation procedure is well known, and will allow you to build a single-frequency receiver. The military P/Y code generation is classified or restricted informatio

      • Spread spectrum is actually a pretty rare modulation method in the satellite world, at least it is for anything other than telemetry and a few other odds and ends. You don't come across it very often though you can definitely see all of them with any half decent spec/an. Contrary to what a lot of people say, they are far from undetectable, they do stand out in their own way, usually a decent number of dB above the noise floor.

        Some of the RADAR specific stuff I used back in the day went from DC right up to a

    • by Lumpy (12016)

      Simple, Switch mega-maid from suck...... to BLOW!

    • by databyss (586137)

      Obviously, the best way would be space traveling sharks with laser beams mounted to their heads.

  • Good. (Score:3, Interesting)

    by EdIII (1114411) * on Friday June 27, 2008 @04:50AM (#23964545)

    Thank God. I think they should be jamming GPS in some places. Or more specifically, start jamming some people's GPS.

    It might start people actually thinking on their own. I know one bridge that has been hit 12 times in the last 3 years by trucks that were too tall. In the last 10 years before that, I was told only 2 people hit the bridge.

    Wanna take a guess how many of these new truckers are just listening to their GPS units blindly?

    • Re:Good. (Score:5, Interesting)

      by Anonymous Coward on Friday June 27, 2008 @04:58AM (#23964597)

      Some people still think that GPS can select devices and that it sends the coordinates to the devices. But it's more like observing stars (or quasars): You calculate the position out of a timestamp from the satellites. And the only thing encrypted is the more accurate timestamp, reserved for military/people paying. The satellite doesn't really care if there are devices at all, it just sends everywhere.

      • Re:Good. (Score:4, Interesting)

        by ChrisMP1 (1130781) on Friday June 27, 2008 @07:05AM (#23965395)
        Even better: My father thinks that the GPS receiver actually makes a transmission to the satellite, and that the 'guvmint' is monitoring these transmissions. (His paranoia would probably make him a good /.er, actually...)
        • Re: (Score:3, Insightful)

          by badfish99 (826052)
          Lots of things are advertised as "GPS tracking devices", so it's easy to see how the technically naive would come to the conclusion that the GPS system somehow keeps track of these "tracking devices".
    • Re: (Score:2, Funny)

      by Dan541 (1032000)

      I don't understand why people bother with GPS I had one but their is very little point in them for road use.

      • Re: (Score:3, Insightful)

        by Kentaree (1078787)
        Clearly you've never tried to navigate Irish roads using the road signs
        • Re: (Score:3, Interesting)

          by Cytotoxic (245301)

          Holy crap, I gotta agree with that. I had a great vacation in Ireland (doing a B&B tour) but I would have been dead in the water without GPS. Most places there have no signs, and the signs that do exist require you to stop and carefully read. But what a great place - I highly recommend a getaway to Ireland. Just make sure you rent a good handling compact with a GPS - the roads are tiny, bumpy, closely bordered by stone walls and driven at breakneck speeds. (Ok, breakneck on these roads is ~100km/hr,

          • Re: (Score:3, Interesting)

            by PachmanP (881352)

            Many of the best landmarks would be extremely difficult to find with a map. I visited some of the ancient dolmen in the Burren and the GPS took me right there. Even with GPS they were tough to spot - a pile of rocks in a field that is nothing but a bunch of rocks. With a map - wow, that would be tough.

            Well actually you seemed to have only found a pile of rocks in a field. The dolmen in Burren is really really impressive. There are some rock piles just down the road though. Seems like GPS kinda failed you.

    • Re:Good. (Score:5, Insightful)

      by Anonymous Coward on Friday June 27, 2008 @05:22AM (#23964745)

      I think they should be jamming GPS in some places. Or more specifically, start jamming some people's GPS. [...] I know one bridge that has been hit 12 times in the last 3 years by trucks that were too tall.

      You don't need a GPS jammer.

      If your bridge is 8 feet high, you simply need a metal arch 9 feet high, and a 'low bridge' sign suspended from it by two one-foot pieces of chain.

      Hence, any driver approaching the bridge who should fail to notice the 'low bridge' sign will have their attention drawn to it when it collides with their vehicle, causing a loud noise but less danger than a vehicle-bridge collision.

      • Re: (Score:3, Funny)

        by EdIII (1114411) *

        LOL!

        That is such a great, simple, and elegant solution. You fail to mention that the sign would be placed a couple hundred feet away from the entrance to the bridge/tunnel, but I assume you meant to say that.

        However, this is probably too intelligent to be implemented anywhere. You're too smart to work for government buddy. Sorry :)

        • Re:Good. (Score:4, Insightful)

          by irtza (893217) on Friday June 27, 2008 @05:41AM (#23964841) Homepage
          These already exist in shopping malls - like to the entrance of a top deck parking lot secondary to weight constraints. Implementing them on the roads would likely be as easy.
        • There is a sign like this, IIRC, protecting the railway bridge at Creswell in Derbyshire.

          Actually, it's more a series of gantries with hanging chains than a full width arch, but it does the trick.

          I seem to remember seeing one somewhere in Wiltshire as well, but can't remember the exact location.

          So yes - they do exist :o)

        • Re:Good. (Score:5, Informative)

          by Hoi Polloi (522990) on Friday June 27, 2008 @08:34AM (#23966315) Journal

          They already do this for the bridges on Storrow Drive that runs along the Charles River in Boston (they would get jammed under the bridge). Problem was that truckers hit it so much they were regularly destroying the sign. You also need to place it in a spot where the truckers can take an exit instead of trying to reverse up a busy road.

          • by orielbean (936271)
            And the college kids driving the Uhaul to move in for a semester have no idea what's happening as they drive a tall truck for the first time ever... They manage to mangle few underpasses every new semester.
      • Re:Good. (Score:5, Funny)

        by Anonymous Coward on Friday June 27, 2008 @06:13AM (#23965025)

        True Story - Some years back at the Telco Supplier that I worked for we had one of those Corporate awayday things at a Hotel in Bristol - We were all instructed to use the Multi-storey car park nearby. When I drove the 4x4 I had at the time into the car park I noticed one of those hanging signs notifying low headroom and drove slowly under it, relieved not to hear any scrapes..

        Later, during the presentations from the PHB's, one of them confessed that he and another PHB had arrived in his new BMW X5 and when they saw the same sign he asked his passenger to get out and make sure they could pass beneath it safely.. He started edging forward as the passenger called out 'Ok, Ok, keep it coming etc.' And then they were through but he was quite disconcerted at how close the ceiling seemed to be as they drove up through the car park and he commented on this to the passenger and asked how much clearance there had been between the car roof and the hanging sign. The reply was something like "Oh none, so I just held the sign up a couple of inches.."

        I think he was the Technical Services Manager...

      • It's sad that a McDonalds' drive thru is more advanced than a highway. Every drive thru has a height bar to stop the roof being ripped off by a too-tall of a truck.
        • Re:Good. (Score:4, Insightful)

          by databyss (586137) on Friday June 27, 2008 @07:09AM (#23965429) Homepage Journal

          It kinda makes sense.

          McD's is a mega-corp who makes more money by being convenient. It's convenient for a trucker to know whether or not they're going to damage their ride, and it's convenient for McD to not have to kill their profits by constantly repairing smashed buildings.

          Bridges OTOH are lowest-bidder type contracting (I'm assuming). The contractor gets no benefit if they're never called back for repairs and overhauls.

          • Re:Good. (Score:4, Interesting)

            by Vellmont (569020) on Friday June 27, 2008 @10:43AM (#23968245) Homepage


            Bridges OTOH are lowest-bidder type contracting (I'm assuming).

            Not in Minnesota at least.

            After the bridge collapse there were several bids to replace the 35W bridge by different contractors. The DOT eventually picked one of the more expensive, and slightly slower proposals because they preferred the construction techniques. The low price bidder even threatened to sue because they thought it was all based on price. So no, price isn't always the only factor in bridge construction.

      • I used to work in a an office in the English-Philosophy Building at the University of Iowa. The street in front of our window, Iowa Avenue, had a low bridge accompanied by a warning side about a 100 feet away with chains that dangled down to hit the roof or window of vehicles too tall to make it under the bridge. I'd say about twice a summer, when all the students were moving, moving trucks would ignore the horrible crash of the chains to next produce the extremely loud boom of a truck smashing off the firs
        • by Pig Hogger (10379)
          Railroad rules call for a bridge to be inspected whenever it is hit by a vehicle.

          While a friend of mine was the stationmaster at $MAJOR_COMMUTER_RAIL_TERMINAL, I was near one such (amply signalled) bridge when I heard a loud noise. When I arrived at the bridge, there was this big van with the roof dangling in the back, neatly folded like an accordion.

          Of course, as always, 911 was totally useless (they don't know the railroad emergency numbers), so I went to $MAJOR_COMMUTER_RAIL_TERMINAL to warn my friend,

      • The Bankhead tunnel in Mobile, AL has a concrete facade, a flashing light, and multiple signs saying no trucks... Yet occasionally a truck still makes an attempt to enter it and fail miserably.
      • I think they should be jamming GPS in some places. Or more specifically, start jamming some people's GPS. [...] I know one bridge that has been hit 12 times in the last 3 years by trucks that were too tall.

        You don't need a GPS jammer.

        If your bridge is 8 feet high, you simply need a metal arch 9 feet high, and a 'low bridge' sign suspended from it by two one-foot pieces of chain.

        Hence, any driver approaching the bridge who should fail to notice the 'low bridge' sign will have their attention drawn to it when it collides with their vehicle, causing a loud noise but less danger than a vehicle-bridge collision.

        We have this near my house by an underpass. Unfortunately there's no sign of former collision on the signs (one at each end). That'd be really cool to see.

      • Re:Good. (Score:4, Funny)

        by Pig Hogger (10379) <pig.hogger@g[ ]l.com ['mai' in gap]> on Friday June 27, 2008 @09:11AM (#23966793) Journal

        If your bridge is 8 feet high, you simply need a metal arch 9 feet high, and a 'low bridge' sign suspended from it by two one-foot pieces of chain.

        (It's called a "tell-tale").

        I've seen better. In Toronto, underpasses have a photocell (and light source) setup 200 feet from it, and a flashing light "too high truck" is fitted on the underpass. The flasher kicks-in whenever the light beam is interrupted.

        And, yes, kids *DO* take a plank and cut the light beam whenever a truck goes by...

    • Re:Good. (Score:4, Insightful)

      by ledow (319597) on Friday June 27, 2008 @05:22AM (#23964751) Homepage

      The GPS is not the problem here, it merely exposes an already-present problem. Stupid drivers who don't know the height/width of their vehicle (despite having driving qualifications that require them to do so). Stupid drivers who can't read signs. Stupid drivers who LOOK AT THEIR GPS while they are driving - every single GPS has a warning on it about this, some of them even announce it every time you turn them on. EYES ON THE ROAD. Then, using a GPS is no more dangerous than taking a driving test - you are following oral instructions from something within the car but your FULL attention is on the road. If your driving examiner tells you to mow the old lady down or speed up to 80 in a 30 area, you wouldn't do it, so don't follow what the GPS tells you blindly.

      It's like saying that speed cameras are at fault because people brake heavily before them. They are not, they are exposing the problem that stupid drivers have always existed and yet nothing is done about them. You should ALREADY be at the speed limit (in fact, significantly less than, in almost all circumstances). If you have to brake heavily, the problem is YOU. YOU have created the hazard yourself. In the same way, you can't "blame" a plastic bag flying in front of your car for the accident that meant you hit someone in front, who was not a safe distance away. YOU were too close. YOU shouldn't be. YOU did not have a safe braking distance between you and the car in front. The plastic bag didn't press the throttle for you or cut your brake lines.

      The solution to these problems is not to jam GPS or get rid of speed cameras, but to START TAKING PEOPLE'S LICENSES AWAY. If you do either of the above, you are NOT fit to drive. You would not pass the legally-required driving standard that you HAD to pass to get a license in the first place. We know you're CAPABLE of doing it because you have done it at some point in the past. So you have NO excuse. If a pilot crashed his plane because he was going too low, he'd not only have his license revoked, he'd be before a serious court very, very quickly. What makes you think a ton of solid metal on four wheels should be any different? Or worse, in the case of lorries, up to 18 tons in the hands of someone who can't tell they won't fit under a bridge! Do you want drivers like that on the road, who can't judge to within a foot or so whether they'll make contact?

      Don't blame the GPS, blame the idiot who didn't read the signs.

      • Re:Good. (Score:5, Insightful)

        by Kreigaffe (765218) on Friday June 27, 2008 @05:41AM (#23964845)

        I was with you until the significantly-less-than-the=speedlimit part.

        That's just ridiculous. Speed limits are almost as a rule too *low*, not too *high* -- and on a highway, traffic moving significantly slower than the majority of other vehicles presents a hazard. A car going 5mph under the speed limit is more of a hazard than a car going 5mph over -- why? Because the slow car causes ALL the traffic moving at the speed limit to pass it, while the fast car causes ONLY ITSELF to pass traffic moving at the speed limit.

        • Re:Good. (Score:5, Insightful)

          by EdIII (1114411) * on Friday June 27, 2008 @06:03AM (#23964965)

          Good point. A state trooper once told me that the absolute safest speed to travel was the AVERAGE speed of the cars around you. Don't go slower than the rest of the cars, and don't go any faster either.

          I won't call the parent of your post arrogant exactly, but his type reminds of the people who think it's okay to drive 61 mph in a 65 mph zone in the FAST LANE.

          Yeah, sure they are technically correct but intentionally and more than a bit arrogantly lack any pragmatic approach to driving on the road.

          It does not matter if the law says 65. If everybody is doing 74, and some people in the fast lane insist on doing 85, then getting in the fast lane and stubbornly insisting on doing 61 creates an unsafe environment for the rest of the drivers.

          I have relatives that drive on the Autobahns tell me that if somebody got into the fast lane on the Autobahn and did not get up to speed that the police would pull them over immediately and cite them. If somebody stayed too long in the fast lane, they would be cited too. The leftmost lane is ONLY used for passing. Can you even imagine if that was enforced in the US?

          • I appreciate the Germans' acceptance of order in the autobahn, for that reason: You are in the right lane or passing those who are. Not complicated.

            I used to live in an outlying town, commuting an hour on an interstate highway each way. In general, the other drivers were competent and just wanted to get to their destinations with minimal fuss.

            Between Thanksgiving and Christmas we had Grandmas and Grandpas on the freeway for the first time in a year, on shopping for Christmas. Between mid-June and late Augus

          • Re:Good. (Score:4, Informative)

            by jdschulteis (689834) on Friday June 27, 2008 @09:11AM (#23966797)

            his type reminds of the people who think it's okay to drive 61 mph in a 65 mph zone in the FAST LANE.

            Yeah, sure they are technically correct but intentionally and more than a bit arrogantly lack any pragmatic approach to driving on the road.

            In Wisconsin at least, left lane squatters are not "technically correct". The statute requires vehicles traveling "at less than the normal speed of traffic at the time and place and under the conditions" to be driven in the right-hand lane. It doesn't matter what the speed limit is. Since this behavior tends to provoke unsafe driving by others if not outright road rage, I think citing more people for it would definitely make the roads safer.

          • Re: (Score:3, Informative)

            by dunkelfalke (91624)

            there is a so called "rechtsfahrgebot" in germany. it is a rule of the german road traffic regulations that (more or less) states that on the roads out of a town you always have to drive at the rightmost lane possible.

          • by D Ninja (825055)

            Can you even imagine if that was enforced in the US?

            I wish! Biggest pet peeve - people who insist on enforcing speed by sitting in the left hand lane. And, then, of course, when you have the nerve (and oh, what nerve I have) to pass them in the right hand lane, they flick you off or make some other rude gesture.

            Happened to me the other day. I didn't tailgate or cut him off or anything. (I did flick my lights after about 6 miles of him sitting in the left lane right next to the car in the right.)

      • Re:Good. (Score:4, Insightful)

        by Savage-Rabbit (308260) on Friday June 27, 2008 @05:48AM (#23964883)

        It's like saying that speed cameras are at fault because people brake heavily before them. They are not, they are exposing the problem that stupid drivers have always existed and yet nothing is done about them. You should ALREADY be at the speed limit (in fact, significantly less than, in almost all circumstances). If you have to brake heavily, the problem is YOU. YOU have created the hazard yourself. In the same way, you can't "blame" a plastic bag flying in front of your car for the accident that meant you hit someone in front, who was not a safe distance away. YOU were too close. YOU shouldn't be. YOU did not have a safe braking distance between you and the car in front. The plastic bag didn't press the throttle for you or cut your brake lines.

        It is amazing how many people fail to understand that. However, maintaining a safe braking distance between yourself and the car in front can be almost as dangerous as going to close. People will abruptly change lanes, usually without using the indicator light to warn other drivers of their intention or only switching on the light after they have begun changing lanes, and then proceed to cut you off. The result is all to often that you have to slam down on the brakes to avoid slamming into the car that cut you off. And that is exactly what you were trying to avoid in the first place by maintaining a safe braking distance.

        • Re:Good. (Score:5, Interesting)

          by FelixGordon (1132635) on Friday June 27, 2008 @07:06AM (#23965407)
          Yeah, but honestly, a driver paying attention and maintaining a preference for a truly safe braking distance isn't jumping on the brakes the moment a car slips into the lane in front of them.

          Slamming down on the brakes like you describe obviously increases your odds of getting rear ended in certain situations, especially if you're driving below the speed limit. But the reality is, you're a cautious driver, you see the person indicate to pull in front of you, often taking advantage of the fact that you're going under the limit - themselves wanting to drive on the limit or above it. You aren't going to hit them, so just maintain your speed. If you know you've got someone up _your_ arse, tap the brakes so the person behind you wakes up and realises you're behaving less predictably than earlier.

          Most likely, the person in front is going to get further away as they ride the limit and stick right on the tail of the person in front, while you stay safe. Less likely, you have to ease your speed down to a distance you're comfortable with. Even _less_ likely is the car infront of you has to suddenly slam their brakes on - in the moments after switching lanes - to avoid killing someone, and you smash into them. But since you're so careful, I assume you had your eye on the road ahead anyway.

          tl;dr, grandpa? drive defensively, drive smart, don't act unpredictably unless it serves your interests to draw attention to yourself on the road.
      • Re:Good. (Score:5, Funny)

        by Thanshin (1188877) on Friday June 27, 2008 @06:08AM (#23964997)

        If your driving examiner tells you to mow the old lady down or speed up to 80 in a 30 area, you wouldn't do it

        Clearly you didn't get your license in Spain, where some people spend up to 3500e ($5514.95). Where each fail after the first four can cost you 1500e. Where some people offer money, sexual favors, etc to the examiners.

        If the examiner tells you to mow down a lady, you ask "HOW HIGH!".

        • Re: (Score:3, Funny)

          by databyss (586137)

          Interesting..... sexual favors you say?

          Is it a requirement to speak Spanish to be an examiner in Spain? Would pig-latin pass?

          I think this is a job I could do.

      • by Fred_A (10934)

        Stupid drivers who LOOK AT THEIR GPS while they are driving - every single GPS has a warning on it about this, some of them even announce it every time you turn them on.

        The problem is that people remove the sticker covering the screen that says so. I'm pretty sure you're supposed to leave it on.

      • Can I add people texting on thier phones to that list? Like the woman I passed on the way home who was drifting out of her lane and jerking it back in suddenly? I didn't see her look up once.

    • Re: (Score:3, Insightful)

      by dreamchaser (49529)

      Ah yes, let's continue to cater our lives to the lowest common denominator. After all, taking GPS away from people who use it responsibly is far better than other solutions that might be evident...like say increasing fines for asshats who are not paying attention and hit bridges.

      • Why not? We already alter every other law to cater to the "But what about the children!?" crowd at the expense of the freedom of adults or other kids. One kid gets hurt hurt in a playground and before you know it they are only allowed to play with bubble wrap.

    • Don't know where you live, but in the UK you can get complete sets of locations of bridges, nicely sorted into collections like "9 ft 6 inch", "9 ft 7 inch" etc. etc. Just take the right collection for your truck, copy it on your Tom Tom, and it will warn you ahead of every low bridge.
    • I honestly don't think that it has anything to do with GPS. I mean, have you seen the size of trucks these days? Its probably a side effect of the hormone filled meats they ate when they were just little personal transports. Also, is it just me or are the new rigs getting crazier and crazier with their axles. Back in my day, 4 was enough for anything...now you're seeing all of these high fangled 6'ers and 8'ers.

      Get off my roadway!
  • by Kamineko (851857) on Friday June 27, 2008 @05:07AM (#23964651)
    "Were jamming, jamming, and I hope you like jamming too"
  • From TFA:

    Hacker sites also publish instructions for a "do-it-yourself GPS jammer that can have a range of up to several hundred feet. Keep in mind this is not an easy hack; a bachelor's in electrical engineering seems like a prerequisite." The parts can be obtained at shopping-mall electronics retailers.

    Why would anyone want to do that on such a large scale? That's just being nasty. I seriously hope that anyone who gets caught using such a device gets a mandatory prison sentence. After all, if you're b

    • Re: (Score:3, Informative)

      by jrmcferren (935335)
      Fines from the FCC range from $7,000 to $10,000 dollars per offense for such illegal operations. There may be other laws on this due to the fact that people rely on these things heavily.
    • Re: (Score:2, Informative)

      by johanw (1001493)
      Just to be sure it works on the receiver your boss or the police put on your car? In some European countries the government wants to use GPS modules to tax car traffic: an excellent reason to jam them.
      • by Detritus (11846)
        It's much simpler and cheaper to cover the antenna with a piece of aluminum foil.
    • Re: (Score:3, Interesting)

      You can blame AF Space Command. This was accomplished years ago as a challenge project by a team of young AF officers under a "fresh ideas" program. Teams are formed from selected applicants and given a small budget and few weeks to develop and execute a proposed space related project using off-the-shelf, commercially available items. One of these teams was concerned about GPS jamming and built a jammer. Range was limited, of course, but the threat was proven to be real.

      As others have pointed out, brute

  • GPS is only necessary to obtain current location of the JDAM once along the flight path. Once the position is known to a reasonable degree of accuracy, the on-board AHRS can take over and still deliver the payload to within about 1mm/km of distance traveled.

    • I have heard from friends who should know this sort of thing that it's closer to 1 nautical mile/hour of flight time divergence for USN/USAF munitions INS.

      (Although it may be different for JDAMs, which are necessarily much shorter ranged than cruise missiles).

  • by plasmacutter (901737) on Friday June 27, 2008 @06:16AM (#23965043)

    Given the continued insistence my government has on collaborating with my mobile carrier, I want to buy a jammer I can hook into the power source on my phone to jam it off their radar. 40-50cm range should do it.

  • Galileo (Score:3, Informative)

    by chrb (1083577) on Friday June 27, 2008 @06:39AM (#23965201)

    Don't forget the huge disagreement [newscientist.com] between the US and Europe over the Galileo satellite system. The EU intended to use the GPS military band carrier frequencies for Galileo, so that the US couldn't jam it without also jamming the signal used by their own armed forces. Eventually the EU backed down and agreed to use separate frequencies.

  • by v1 (525388) on Friday June 27, 2008 @06:41AM (#23965213) Homepage Journal

    That second link is seven pages. Normally anything posted to /. that's more than say, three pages, consists of 400k size pages of advertisements, banners, and otherwise obnoxious noise with maybe three paragraphs (4k or so) of actual content in the middle of the page, that you have to continuously click (NEXT PAGE) to read the next few sentences on.

    Not that one. Actual, real content. Multiple pages of real information. What has the world come to? Someone's posting content for the purpose of actually informing us, rather than burying us in cheap banner hits.

    The first link is possibly even better than that though. The same information density, in only ONE page. Normally they'd have spread that among at least five banner-whoring pages? Kudos to gpsworld.com for serving their readers. It's pages like that which make me wish I could leave my banner-blockers turned off all the time.

    • by RobBebop (947356)

      Even crazier is that fact that your post was modded "Insightful", and is the reason that I am going to actual RTFA.

      Thank you, kind article reading, sir. Hopefully your good will and optimism rubs off on the /. editors and they will start to actively filter AD PAGE LINKS from being published to the main page.

      One can only hope...

  • by s31523 (926314) on Friday June 27, 2008 @07:57AM (#23965871)
    It is worth noting that the Tomahawk missile is equipped with a precision INS and Terrain Contour Matching systems. By the time a Tomahawk nears its target GPS is not really being used. The GPS is used heavily right after launch to correct errors in the INS, once within 30 minutes TOT the weapon doesn't need GPS to hit its target with precision. Jamming of GPS usually is going to occur within a limited range of targets, so jamming is basically useless at that point

    Also, don't forget that SEALs usually are the first on the scene to paint targets with a laser so LGBs can be deployed from high altitude aircraft to take things like jamming equipment out.

    There is a definite threat, but rest assured, our ability to blow stuff up is not greatly hindered by GPS jamming.
  • Jammers don't usually cause a problem for the more sophisticated military. In essence, jamming is just broadcasting a very loud signal on the same frequency as the one you want to jam, so that you drown out the real signal.

    The problem with broadcasting loud signals is that they are very good for locking bombs/missiles onto. The Americans have anti radar missiles that home in on radar signals. The Russians (used to?) have an air squadron that just flew around the battlefields dropping bombs on the largest tr

  • We already depend on GPS for ship navigation, especially for close-in navigation around harbors. We would like to use GPS as a substitute for radar in airplane airport approaches. Eventually, we need to make cars with autonomous navigation, which would likely use GPS at least partially.

    The prospect of GPS jamming is a major impediment to all these dependencies. Many civilian applications really can't go forward without sufficient security.

    Do slashdotters know of non-GPS jamming-immune, ways to do marine, a

  • If I remember correctly, GPS simply measures an extremely accurate and precise time signal from several satellites and measures the discrepancy between them. So, could one rebroadcast the time signal advanced or retarded a few nanoseconds to confuse the GPS. Is this how the jammers work, or do they just jam the signal with garbage?

    The Langley article was too technical for me.
    • by russotto (537200)

      So, could one rebroadcast the time signal advanced or retarded a few nanoseconds to confuse the GPS. Is this how the jammers work, or do they just jam the signal with garbage?

      Sending a stronger, fake GPS signal is called spoofing, and is one of the reasons the precise GPS signal is encrypted (it's even called A/S for anti-spoof). Jamming just means making the real signal unreceivable.

      • by Thelasko (1196535)
        precise GPS signal is encrypted (it's even called A/S for anti-spoof).

        Why couldn't one record a GPS signal in a buffer and rebroadcast it nanoseconds latter?

    • This is how many modern target specific jammers work in the military, particularly in relation to RADAR. To answer your question, yes, you could do this to create a bigger error in nearby receivers, though it makes more sense to spoof all the visible satellites rather than just one at any given point in space and time.

      How current GPS jamming works is as you describe. Noise.

      Ultimately swamping the GPS transmissions with noise is far more effective than spoofing. For military situations you could almost be ce

  • by KeithH (15061) on Friday June 27, 2008 @09:08AM (#23966767)

    CDMA relies on GPS for its timing. Every cell tower has a GPS receiver so that it can synchronize its time with other cells (and the RNC at the centre of the cell network). Timing accuracy is a fundamental part of CDMA's hand-off design.

    This problem was encountered in China caused by their military. They literally had a truck driving around jamming the GPS signal making for intermittent problems - always the most difficult to investigate.

  • by howardd21 (1001567) on Friday June 27, 2008 @12:05PM (#23969655) Homepage
    Considering that GPS is often used to monitor fleets or even driving patterns by insurance companies, it may be helpful to jam my own GPS. It would allow me to go to the corner bar and hang out for awhile, and then resume my route. I do not need to jam the whole system, just my little corner of the world, corner bar that is...

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