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Finnish Hacker Isolates Helicopter GPS Coordinates From YouTube Video Sounds 163

Posted by Soulskill
from the curiosity-leads-to-the-best-hacks dept.
An anonymous reader sends a post by Finnish electronics hacker Oona Räisänen, who heard a mysterious digital signal in the audio accompanying a YouTube video of a police chase. The chase was being filmed by a helicopter. Räisänen wrote: "The signal sits alone on the left audio channel, so I can completely isolate it. Judging from the spectrogram, the modulation scheme seems to be BFSK, switching the carrier between 1200 and 2200 Hz. I demodulated it by filtering it with a lowpass and highpass sinc in SoX and comparing outputs. Now I had a bitstream at 1200 bps. ... The bitstream consists of packets of 47 bytes each, synchronized by start and stop bits and separated by repetitions of the byte 0x80. Most bits stay constant during the video, but three distinct groups of bytes contain varying data." She guessed that the data was location telemetry from the helicopter, so she analyzed it to extract coordinates. When she plotted them and compared the resulting curve to the route taken by the fleeing car in the video, it was a match.
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Finnish Hacker Isolates Helicopter GPS Coordinates From YouTube Video Sounds

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  • what an ep1c hack (Score:5, Insightful)

    by Connie_Lingus (317691) on Saturday February 01, 2014 @01:55PM (#46129357) Homepage

    i think i'm in love with this women.

    • by rvw (755107) on Saturday February 01, 2014 @02:23PM (#46129533)

      i think i'm in love with this women.

      Steal a car and make sure it is at prime time!

    • Re: (Score:3, Insightful)

      by Anonymous Coward

      It's sad that this got an insightful mod. The fact that everyone jumps to potential mate every time a woman does something is one of the biggest barriers to women in technical fields.

      • Re: (Score:3, Interesting)

        by K. S. Kyosuke (729550)

        The fact that everyone jumps to potential mate every time a woman does something is one of the biggest barriers to women in technical fields.

        If your logic is correct, that might just clean up itself nicely when more women start "doing something". Either that, or your logic is wrong, seeing as humanity survived for many millennia without women doing nothing.

        • by mwehle (2491950) on Saturday February 01, 2014 @04:02PM (#46130067) Homepage

          If your logic is correct, that might just clean up itself nicely when more women start "doing something". Either that, or your logic is wrong, seeing as humanity survived for many millennia without women doing nothing.

          I'm going to have to go with possibility two here. I believe humanity survived for many millennia "without women doing nothing". I would in fact go so far as to moot the proposition that should women begin doing nothing humanity may indeed not survive.

      • by russotto (537200) on Saturday February 01, 2014 @03:51PM (#46130017) Journal

        Right, men should be attracted to women only because of their purely physical charms, not because of anything they actually do. And by "men" I mean "not neckbearded nerds", who should just stay in their fucking parents basements and forget about any sort of relationship.

        • by epyT-R (613989)

          Well, these days, lots of men are realizing that relationships aren't worth the time, resource, and legal risk, and many of them are not 'neckbeard nerds.'

        • by AmiMoJo (196126) *

          Whoosh. It's not got anything to do with why the guy was attracted to her, it's the fact that rather than focus on the technical achievement first. Consider what it is like for a women trying to present something like this at a conference and knowing that the first thing half the guys in the audience do is evaluate her as a potential target for their (unwanted) affection. How do you think it feels trying to engage in a debate about something you did when the first comment is like that?

          I wonder if this happe

          • by Anonymous Coward
            Yes, how horrifying it must be that people find your intelligence attractive.

            Sexuality is human nature. What she "knows" (which is bullshit, by the way; she doesn't "know" this, she might suspect it but it is an assumption at best) is largely irrelevant anyway. What matters is how people treat her and how she deals with that. If someone treats her differently and she doesn't appreciate the way that person is acting, she should (and likely will) tell them to knock it off. If it escalates past that, that's
      • by g0bshiTe (596213)
        That and their boobs get in the way of everyone elses work.

        Ever tried to work while staring at a womans boobs?
      • Re: (Score:2, Interesting)

        by Anonymous Coward

        Right, like women don't hit on the men in female dominated industries, subject them to advances, and then leaving him wondering if he'll lose his job for saying 'yes', or for saying 'no.' This happens in heterogenic offices, so I see no reason why it wouldn't be worse in this circumstance.

        It's not that propositioning someone is really a bad thing, but the government granted trump cards women have make their behavior a genuine threat to men. Really, it's women who should learn to take it as compliments rat

      • by SuperBanana (662181) on Saturday February 01, 2014 @10:32PM (#46131843)

        It's sad that this got an insightful mod. The fact that everyone jumps to potential mate every time a woman does something is one of the biggest barriers to women in technical fields.

        First off, if you think "mate" is what love is about, you're the one with the problem.

        Second, one person is not "everyone."

        Third: did you really think the poster was serious? It was a hyperbolic statement, meant as a strong statement of respect.

        Fourth: we can't desire a woman's lifelong companionship for her body (sexual objectification), but please do explain what is wrong with desiring a woman's companionship for her impressive work? Because you do realize that damn near every straight woman on this planet selects her mate by his accomplishments, wealth, and social standing, right?

        • by sumdumass (711423)

          Lets look at this from a woman's perspective. I'm not a woman but I have had many of them and ended up pissing them off quite effectively so I know a bit about it. When a woman does something, extraordinary or not, she shouldn't have to put up with comments or concepts that reduce her to a baby factory. If someone on the outside looks and see that every time some butt ugly girl does something, they will be subjected to this type of harrassment, how many of them will join that field when it is much easier ju

          • by Cederic (9623)

            Just like finding out your daughter's boyfriend only asked her on a date because he saw her doing the splits or eating a banana makes him a lot creepy.

            Having observed female teenagers simulate fellatio on a banana specifically to attract male attention, you tell me: Who's at fault here?

            By 'simulate' I include using their teeth to create the semblance of a glans before demonstrating deep-throating technique, inserting and withdrawing fully without biting. Or maybe I'm naive and everybody eats a banana that way.

            • by sumdumass (711423)

              Perhaps we should save the sexualization of women for when they not only deep throat a banana as a juvenile but parade it as their significant achievement when they are an adult.

              I'm not at all saying you can or should never treat a woman like a whore, I'm saying that we shouldn't be doing it when their actions are the furthest from it. There is a huge difference between discovering a signal buried into an audio channel of a recording and detailing/documenting the attempts to decode it and deep throating a b

          • by ultranova (717540)

            When a woman does something, extraordinary or not, she shouldn't have to put up with comments or concepts that reduce her to a baby factory.

            Fair enough. Going from "I'm in love with person X due to their impressive skills and achievements" to "person X is just a baby factory" isn't. It's insane troll logic.

            So if a woman has to fend off approaches or put up with sexualized comments every time they accomplish something, how long do you think they will continue to accomplish things? How is this any different

            • by AmiMoJo (196126) *

              Power. A random Slashdot commenter doesn't have the power to affect your future in any way, while your boss does. You can't abuse someone you have no power over. At most you could annoy them - and even that is unlikely here, since OPs comment was not actually directed to the woman in question but to OPs own social group.

              What a bizarre argument. Just because someone doesn't have power doesn't mean that being a dick is somehow acceptable. They might be someone's boss, or might become a manager one day, and their views are not suddenly doing to change.

              We have to deal with these attitudes where we find them, not find excuses for them.

              People ask other people on a date because they find them sexually attractive.

              Wow, what horribly shallow and unfulfilling relationships you must have. Personally I find that most women are sexually attractive if I have a connection with them, regardless of looks. About 98%*

              • by ultranova (717540)

                Just because someone doesn't have power doesn't mean that being a dick is somehow acceptable.

                I never said it was. And sexual extortion goes a bit beyond "being a dick".

                They might be someone's boss, or might become a manager one day, and their views are not suddenly doing to change.

                Do you think it would be appropriate for a boss to ask their underling out? Likely not. Is it appropriate to ask their peer out? Yes. The limits of appropriate behaviour do change all the time depending on the relative roles of

          • The OP's comment did not "reduce her to a baby factory."

      • by wasteoid (1897370)
        I think I'm in love with this AC woman; her post is insightful.
      • Right. So finding women attractive for their intelligence is a bad thing. Got it.
      • The fact that everyone jumps to potential mate every time a woman does something is one of the biggest barriers to women in technical fields.

        It's very good for the evolution of our species, though.

    • She doesn't care about you, she's in love with a journalist and currently wanted for triple murder. Too busy a schedule.
  • by Anonymous Coward on Saturday February 01, 2014 @01:58PM (#46129387)

    I'll be in the kitchen, making this woman a sandwich.

  • by 93 Escort Wagon (326346) on Saturday February 01, 2014 @02:05PM (#46129413)

    She washe one driving the car being chased by the police.

  • Brilliant hack! (Score:5, Interesting)

    by HellCatF6 (1824178) <HellCatF6@gmail.com> on Saturday February 01, 2014 @02:08PM (#46129443) Homepage

    There was a time, before we all lost our minds to Pong, Asteroids and Zelda (yes, I go way back) where we also spent time taking our world apart and figuring out how to make it better.

    Oona rocks! She should be rewarded somehow.

    BTW - the end of the article finally explains how a megahertz signal found its way onto the audio track.

    • by Anonymous Coward

      Oona rocks! She should be rewarded somehow.

      Yeah, rewarded with the slobbering accolades of a bunch of pathetic dimwitted neckbeards who want to confess their undying love for her.

      Her accomplishment is more on the lines of "hey, that's pretty damn clever" rather than "OMG stop the presses: this WOMAN did something NERDY and I WANT HER!!"

      • Her accomplishment is more on the lines of "hey, that's pretty damn clever"

        Someone doing something clever leads to wanting to have a conversation with them. Why, because you're interested in what they have to say. And that leads to coffee. Sadly, a guy having a private intellectual conversation with a woman is usually viewed as a date by the ignorant masses.

    • by tlhIngan (30335)

      There was a time, before we all lost our minds to Pong, Asteroids and Zelda (yes, I go way back) where we also spent time taking our world apart and figuring out how to make it better.

      Oona rocks! She should be rewarded somehow.

      BTW - the end of the article finally explains how a megahertz signal found its way onto the audio track.

      Too bad it's not completely original.

      Back in the 80s, Star Trek IV was released. In it, a 3 second burst is heard [wordpress.com] that sounded a lot like HF packet. After much effort (this was the

  • Now if she had got the location from the angle of reflected sunlight glinting off objects on the ground and the time of day, I would have been really impressed ;-)

  • by Areyoukiddingme (1289470) on Saturday February 01, 2014 @02:17PM (#46129493)

    Oona had better be glad she's Finnish. If she did that in the US, she could expect jack-booted thugs from Homeland Security bashing her door down. That data is SEKRET! The fact that it's only perceived as secret by said ignorant thugs because the marketing department of the vendor told them so is completely lost in the general panic. TUR'RISTS could FOLLOW the HELICOPTER! Beat to quarters and man guns!

    I'd like to think I was exaggerating for effect, but judging by the past decade, I'm really not. The current security apparatus really is self-parodying.

    (For those who want to bitch about how this perception runs contrary to Slashdot groupthink about the threat posed by that apparatus, I say only this: some of us are capable of projecting into the future. We want the spying and the blundering belligerence stopped because it might not always be blundering or incompetent. It still manages to be mortally dangerous even now. It could get much much worse.)

    • by Anonymous Coward

      It'd make a good article when se travels to US some day..... Arrested in airport.... and so on....

    • by Anonymous Coward

      Come on. I was doing this five years ago to feed GPS coordinates into a videocamera audio input with the purpose of geereferencing video frames (startup of basically three programmers) which were used for road maintenance. We were paid to film the roads, and then people in the office would inspect it, and input proper position (well, precise enough for road maintenance) into a GIS. The development of feeding the GPS into the audio was due to the previous process being clunky: gps coordinates were separate f

  • Finally! (Score:5, Interesting)

    by ArchieBunker (132337) on Saturday February 01, 2014 @02:40PM (#46129629) Homepage

    A story worthy of slashdot. Please post more of these (not being sarcastic).

    • Seconded! (Score:5, Insightful)

      by Okian Warrior (537106) on Saturday February 01, 2014 @02:55PM (#46129701) Homepage Journal

      A story worthy of slashdot. Please post more of these (not being sarcastic).

      I second this.

      I'm adequately supplied with political stories, you can get those anywhere. Stories that raise the indignation level are also common - "oh! how unjust that is!".

      When you have stuff that nerds find interesting that you don't see everywhere else, nerds will come here to see it.

    • by feufeu (1109929)
      This !

      News for nerds at least !

    • by Rakarra (112805)

      This was like a throwback story!

    • I was underwhelmed, but it was clear and concise, and it wasn't obviously mangled for page views the way I'm used to. I might read it again instead of the next politics article for that reason.

  • My new hero..... Good thing she's not in the US :)

    You're not supposed to be decrypting latent signals effectively hidden in the video, to uncover privileged data. The feds would have a field day with anyone in the US who did this....

  • For those born after the 1970s, 0x80 is the sync byte. It's what you would send on serial line protocols when you have nothing to send, in order to maintain synchrony.

     

    • by marcansoft (727665) <hector@nOsPam.marcansoft.com> on Saturday February 01, 2014 @03:10PM (#46129789) Homepage

      0x80 is just a null byte with odd parity. What she apparently missed is that this is bog-standard Bell 202 AFSK (1200 baud) with 7 data bits and odd parity, and the data is ASCII. By throwing away the top nybble, she was throwing away the parity bit and the top 3 bits of the ASCII encoding of decimal digits. The fact that it was a parity bit should've been pretty obvious, since the top nybble flips between 0x3x and 0xbx in the pattern that you'd expect for a parity bit.

      You can decode it with off the shelf software, throw away the top bit, and get back mostly ASCII:

      $ ./minimodem --rx 1200 -f ~/helicopter.wav | tr '\200-\377\r' '\000-\177\n'
      ### CARRIER 1200 @ 1200.0 Hz ###
        282 0002.3
      #L N390374 W09432938YJ
      #AL #NA 282 0002.3
      #L N390374 W09432938YJ
      #AL #NA 283 0002.3
      #L N390372 W09432928YJ
      #AL #NA 283 0002.3
      #L N390370 W09432918YJ
      #AL #NA 283 0002.3
      #L N390370 W09432918YJ
      #AL #NA 283 0002.3
      [...]

      I'm actually surprised that she missed / didn't mention this, considering her experience with signals analysis and demodulation. This is pretty much as basic as telemetry data modulation gets! Then again, as a reverse engineer myself, sometimes we get caught up doing deep analysis of something that later turns out to be totally trivial :)

      • by pe1chl (90186) on Saturday February 01, 2014 @03:25PM (#46129871)

        She mentioned that she used a spectral analysis to deduce that this was 1200/2200 Hz FSK, well I knew that by just listening to it!
        This is exactly the same sound as 1200 baud AFSK amateur packet radio made in the eighties/nineties, indeed using Bell 202 AFSK modems.
        I have heard so many of those packets while seeing them scrolling by on the screen that I can sometimes hear what kind of packet it is by just listening. (of course not the exact content)
        Only in this case it is async serial data, while with packet radio it was HDLC NRZI-encoded sync data. And because in packet radio there are alternating transmissions from different transmitters, you hear a characteristic "leader" pattern similar to the idle pattern in this broadcast followed by a data packet and a keydown of the transmitter.
        She probably was at an advantage not knowing about this, as she did not waste time to see if it was HDLC.

      • She still deserves the sandwich, though.

      • by russotto (537200)

        I'm actually surprised that she missed / didn't mention this, considering her experience with signals analysis and demodulation. This is pretty much as basic as telemetry data modulation gets! Then again, as a reverse engineer myself, sometimes we get caught up doing deep analysis of something that later turns out to be totally trivial :)

        Yeah, I was hoping the article would turn out to be about how the telemetry ended up cross-modulated into the audio feed or something, rather than being standard informatio

      • by Fnord666 (889225)
        Please see her update 2 on the post:

        Update 2: Yes, it's 7-bit Bell 202 ASCII. I tried decoding it as such earlier, but must have gotten the bit order wrong! So I just chose a roundabout way.

  • Someone on this article truly deserves the title of a "hacker"
  • by garry_g (106621) on Saturday February 01, 2014 @03:40PM (#46129953)

    ... and not as the negative it is most often used nowadays ...

  • by eyenot (102141) <eyenot@hotmail.com> on Saturday February 01, 2014 @05:39PM (#46130511) Homepage

    In chemistry and physics courses you'll find you often do lab work not in discovery of new things but to prove things that are already known. It turns out to be pretty simple to do an experiment to prove that two related theories can be measurably shown to be not false, through some apparatus under some paradigm.

    So this woman used existing knowledge of how GPS works, of audio modulated data, and a chase that she also apparently knew the location of, and showed that the location of the chase matches the location being communicated. Okay, so that's cool.

    But what did she accomplish? I am, of course, asking this from the "how is this news" rostrum. It's a great proof of theory but what the hell does it have to do with anything?

    Oh, wait. The elephant in the room. I see what's going on, here, you geeks got all fucked up in the head again because here comes another woman with skills.

    A man who turns into putty for women isn't trustworthy, you know that? Strong women prey on those guys and they become security concerns.

    If you can't treat women as equals, then all of your wowie-zowie about women "doing guy things" is empty. You're more self-impressed at other males than impressed at this woman's potential.

    • by EuclideanSilence (1968630) on Saturday February 01, 2014 @11:31PM (#46132033)

      What this person did doesn't require a lab, or anything that any of us don't have available. A strange sound was heard, and instead of going "hey I wonder what's on TV", the signal was sanitized, it's purpose guessed and then verified to be something understandable by anyone.

      This isn't awesome because it accomplishes something. It's great because it was done for no reason at all. More stories like this please, and anyone who doesn't like it should find one of the million other websites that don't appreciate aimless-but-interesting tinkering.

    • by rastos1 (601318)

      But what did she accomplish?

      She did something that requires skill, knowledge and she did it for fun and interest. How often do you see that? I don't. If you do, share the story. We are eager to know.

    • by AmiMoJo (196126) *

      I read about this when she posted it to G+ a few days ago and took for what it is, an interesting investigation and some nice deduction. It's not really news, except perhaps for the fact that this kind of information is probably leaked a lot more often than most of us realize.

      I don't think it being posted has anything to do with Oona's gender, it's just generally interesting to nerds. We need more stories like this, with plenty of technical detail. Mostly we just get dumbed down tabloid style click-bait.

    • Why does there have to be a reason? "But what"? But nothing. It was for kicks.

      Every once in awhile, can't we just see an article like this and say, "Cool!" without overthinking it?

  • Impossible, audio systems and flight systems never interfere with each other. Any argument the other way is just from a bunch of technophobes. --- summarized from the cell phones on air planes threads.

  • by Anonymous Coward

    Funny how what counts as "magical" nowadays is the human part:

    >What software did you use for the "magical image analysis"?
            Plotting the car's position was actually all manual work. I've done that before from videos.

    Not long ago words like "automagical" were used to describe what a computer does. Is this a shift in perception?

    • A lot of people would like us to think that computers are magic these days, yes. This is problematic for a number of reasons, but a large one seems to be "if it's magic, it will be reliable"...which is obviously false as the "magic" is only as good as the guy who "cast" it...and as soon as anybody actually looks at the program, they find security holes.

      Then we sue them when they point out the holes.

      The contexts I've heard "automagical" used in usually equate to "this should work fine but it's so complicated

  • I'm surprised they're doing in-band signalling with out a band-pass filter, tho I guess maybe they don't count the GPS telemetry as sensitive or they want it archived with the video stream.

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