Mystery signal from a helicopter
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Mystery signal from a helicopter
1–10 of 83 posts
Re: Mystery signal from a helicopter
#2github?
Re: Mystery signal from a helicopter
#3Nice bit of reverse-engineering, and an impressive hack from whoever built the system.
Re: Mystery signal from a helicopter
#4It'd be interesting to scrape videos for this kind of information in order to map them en-masse. Great post!
Re: Mystery signal from a helicopter
#5Nice bit of reverse-engineering, and an impressive hack from whoever built the system.
Not really a hack. Subcarriers are how they added color to TV, stereo to FM radio, and so on. WWV/WWVH also sends machine-readable time codes at 100Hz like this.
Re: Mystery signal from a helicopter
#6Oona's work is always amazing. Loads of interesting hardware stuff in her blog. I wish I would be better at some mechanical engineering/electrical engineering stuff, my work is mostly web-related or big data stuff, never really get my hands dirty :(
Re: Mystery signal from a helicopter
#7Nice bit of reverse-engineering, and an impressive hack from whoever built the system.
Quite funny - I know someone who uses a similar setup to send GPS Coordinates for a Quadcopter and a Plane via the audio channel of the video link (he flies the Quadcopter/Plane with video goggles) to the ground station.
There, an Arduino controls some stepper motors to point directional antennas at the copter/plane.
Project is at https://github.com/KipK/Ghettostation - video at https://www.youtube.com/watch?v=tiO4YCX7hJo - you can hear the modulation in https://www.youtube.com/watch?v=nm0okv8mTsg
Re: Mystery signal from a helicopter
#8I wonder how much audio compression the signal can go through before getting lost, and if joint-stereo affected it. Might have to check out the data myself :) Props to Oona.
Re: Mystery signal from a helicopter
#9can this become/or is/ part of forensic science? if its possible to do the same on a mobile phone, and merely speaking into the phone, you give away your travel trajectory?
Re: Mystery signal from a helicopter
#10can this become/or is/ part of forensic science? if its possible to do the same on a mobile phone, and merely speaking into the phone, you give away your travel trajectory?
No, in this case it was intentionally encoded in the audio.