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Finnish Hacker Isolates Helicopter GPS Coordinates From YouTube Video Sounds
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.
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.
A story worthy of slashdot. Please post more of these (not being sarcastic).
Only the State obtains its revenue by coercion. - Murray Rothbard
So what? It was still fun, as in "this Youtube video contains more data than meets the eyes. Let's find out what it is."
As a ham radio enthusiast, I get the same pleasure decoding the bits of morse code that can be heard in movies from time to time: usually it's pretend morse code, but once in a while you hear a bit of a real transmission that's been overlaid onto the soundtrack by the sound engineer who didn't have a clue that what he used actually meant something totally unrelated to the movie.
In fact, I heard a CQ call followed by a callsign in a scifi B-movie from the 90s once, and sent a QSL card to the owner of the callsign in question. He answered me saying I was one of only 5 people to have done so over the years. How fun is that?
So yes, the code is known, there's nothing special about it, but she had fun digging out unexpected information, and I had fun reading about it. Stop being so jaded.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
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.
Ezekiel 23:20
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 rather than using these hair trigger laws as a rejection tool. The only valid complaints here are when the propositioning party won't back off when asked, but right now, the whiteknight-defined law acts only on women's sayso, with little proof required. It's time to put this behavior in perspective instead of labeling men as pervs for asking women out, or admiring them. Both genders eyes wander. Leave it to the left to criminalize natural behavior.