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Receiving Starlink satellite beacons on a budget

46 points by mickotron 5y ago

ckdarby 5y ago
Dumb question, why?
- eminence32 5y ago
  I guess the post kind of answered this: > Whatever you decide to do with the signal, whether it’s Doppler analysis using software like strf or simply just listening to it for a while and showing it off to people, I hope this post was helpful and cleared things up. This is a unique opportunity to experiment with a whole different frequency band and hardware for SDR owners without having to spend obscene amounts of money on precision, custom, or obscure RF hardware and expensive SDRs. So I'll ask a related followup: can one decode any information from these beacons?
  - jcims 5y ago
    > So I'll ask a related followup: can one decode any information from these beacons? Everything I’ve read about this so far leads me to believe these are just continuous tones that only carry information to the extent that they are operating at specific frequencies relative to other. I’m just casually interested in this stuff and my guess is these are probably used to help the receivers in the user terminals correct for doppler shift in the much quieter broadband transmission frequencies. I don’t know if ‘pilot tone’ would be correctly used here but that’s the term that comes to mind.
  - ackbar03 5y ago
    I'll do one better, has anyone tried decoding the actual signal from the satellites? I guess its probably encrypted but has anyone tried decoding it and sharing their experiences like this author? I'd be very interested
    - jcims 5y ago
      This person has captured the data stream with a fat SDR. https://old.reddit.com/r/StarlinkEngineering/comments/qwm1v5/observations_of_starlink_satellite_to_user/ https://old.reddit.com/r/StarlinkEngineering/comments/qwm1v5... I don’t believe they have attempted to decode it at all but i haven’t read all of the updates. They did confirm they do not see any modulation in these tones.
- jcims 5y ago
  Dumb answer, why not? It’s basically RF photography. No particular utility, just fun to do for yourself.
- Rebelgecko 5y ago
  In conjunction with ephemerides, you could put together a poor man's GPS
- CamperBob2 5y ago
  Dumb answer: Because it's there.
- sneak 5y ago
  Receiving magic signals from outer space is cool.
jcims 5y ago
Minor plug. Airspy had some very high quality SDR receivers and they do a Black Friday sale every year. https://airspy.com/ https://airspy.com/ Not sure when it ends but if you’ve been thinking of dipping your toes into SDR these are good products. I’ve got both the R2 and HF+ products and enjoy them both. RTL’s can’t be beat for price alone but if you’re early distracted by hardware limitations they can be a challenge lol

46 points by mickotron 5y ago

ckdarby 5y ago

Dumb question, why?

eminence32 5y ago
I guess the post kind of answered this: > Whatever you decide to do with the signal, whether it’s Doppler analysis using software like strf or simply just listening to it for a while and showing it off to people, I hope this post was helpful and cleared things up. This is a unique opportunity to experiment with a whole different frequency band and hardware for SDR owners without having to spend obscene amounts of money on precision, custom, or obscure RF hardware and expensive SDRs. So I'll ask a related followup: can one decode any information from these beacons?
- jcims 5y ago
  > So I'll ask a related followup: can one decode any information from these beacons? Everything I’ve read about this so far leads me to believe these are just continuous tones that only carry information to the extent that they are operating at specific frequencies relative to other. I’m just casually interested in this stuff and my guess is these are probably used to help the receivers in the user terminals correct for doppler shift in the much quieter broadband transmission frequencies. I don’t know if ‘pilot tone’ would be correctly used here but that’s the term that comes to mind.
- ackbar03 5y ago
  I'll do one better, has anyone tried decoding the actual signal from the satellites? I guess its probably encrypted but has anyone tried decoding it and sharing their experiences like this author? I'd be very interested
  - jcims 5y ago
    This person has captured the data stream with a fat SDR. https://old.reddit.com/r/StarlinkEngineering/comments/qwm1v5/observations_of_starlink_satellite_to_user/ https://old.reddit.com/r/StarlinkEngineering/comments/qwm1v5... I don’t believe they have attempted to decode it at all but i haven’t read all of the updates. They did confirm they do not see any modulation in these tones.
jcims 5y ago
Dumb answer, why not? It’s basically RF photography. No particular utility, just fun to do for yourself.
Rebelgecko 5y ago
In conjunction with ephemerides, you could put together a poor man's GPS
CamperBob2 5y ago
Dumb answer: Because it's there.
sneak 5y ago
Receiving magic signals from outer space is cool.

jcims 5y ago

Minor plug. Airspy had some very high quality SDR receivers and they do a Black Friday sale every year. https://airspy.com/ https://airspy.com/ Not sure when it ends but if you’ve been thinking of dipping your toes into SDR these are good products. I’ve got both the R2 and HF+ products and enjoy them both. RTL’s can’t be beat for price alone but if you’re early distracted by hardware limitations they can be a challenge lol