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Finnish Hacker Isolates Helicopter GPS Coordinates From YouTube Video Sounds

Posted by Soulskill on 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.

3 of 163 comments (clear)

  1. what an ep1c hack by Connie_Lingus · · Score: 5, Insightful

    i think i'm in love with this women.

    --
    never bring a twinkie to a food fight.
    1. Re:what an ep1c hack by russotto · · Score: 5, Insightful

      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.

  2. Good thing she's Finnish by Areyoukiddingme · · Score: 5, Insightful

    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.)