r/spaceporn Dec 11 '24

Voyager 1 phones home from ~1 light-day away! Related Content

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u/Jisifus Dec 11 '24 edited Dec 11 '24

No. The baseband data is tens of gigabytes, the signal is very narrow and almost indistinguishable from background noise.

If you want to know what a strong terrestrial signal using the same protocol with a low noise floor would sound like, listen to the BPSK31 sample here: https://www.sigidwiki.com/wiki/Phase_Shift_Keying_(PSK))

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u/fuzzbeebs Dec 11 '24

Would we hear a constant tone or is the frequency of the signal outside of the range of human hearing?

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u/Jisifus Dec 11 '24

I don't do physics well enough to explain the difference between an RF transmission as it takes place (at whatever frequency) and how that gets "translated" into something we can listen to. But there's no reason why this specific transmission would be outside of the human range of hearing if sampled correctly. The audio frequency at which a radio transmission gets played back can be easily manipulated by changing the center frequency.

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u/fuzzbeebs Dec 11 '24

Seems like we should still be able to hear it then, unless they are somehow unable to filter background noise. For example a 500Hz sine wave has a bandwidth of effectively 0 but you can hear it perfectly fine. But I guess if we alter the frequency and reduce the sampling rate to fit it on the internet it wouldn't really be the signal anymore.

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u/Comprehensive-Dig165 Dec 11 '24

The link just has jpegs of different signals. I have a radio background from the Army and HAM radio. Figured someone would have a slice of the signal, but I'll have to Google it.

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u/Jisifus Dec 11 '24

There are audio samples next to every waterfall image https://i.imgur.com/EKvJoAI.png

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u/Comprehensive-Dig165 Dec 11 '24

Thanks. Didn't notice. Much appreciated.

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u/Jisifus Dec 11 '24

FYI the data is available at https://breakthroughinitiatives.org/opendatasearch, just enter "VOYAGER1" at the target name field.

Here's a blog entry of someone decoding one of the baseband recordings. https://destevez.net/2021/09/decoding-voyager-1/

As to "playing" it and getting something audible from it... Not sure how to do that. Maybe apps like SDR# can play baseband recordings.

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u/Comprehensive-Dig165 Dec 11 '24

https://youtu.be/LIAZWb9_si4?si=xTM9u-45GKmd-KcD is basically the type of stuff I'm looking for. Playable Audio (open source) that I can then use as sound effects on HFY stories.

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u/Jisifus Dec 11 '24

Yeah a terrestrial PSK transmission is the closest thing you’ll get to that. Anything from the voyager baseband won’t result in anything other than „slightly louder noise“