[HN Gopher] Ham radio operators receive signals from Voyager 1 o...
___________________________________________________________________
Ham radio operators receive signals from Voyager 1 on Dwingeloo
telescope
Author : ForHackernews
Score : 281 points
Date : 2024-12-17 09:56 UTC (3 days ago)
(HTM) web link (www.camras.nl)
(TXT) w3m dump (www.camras.nl)
| LeoPanthera wrote:
| A photo of the dish:
| https://en.wikipedia.org/wiki/Dwingeloo_Radio_Observatory#/m...
| kstrauser wrote:
| Lovely! Those big dishes boggle my mind. For example, about
| Arecibo (https://en.wikipedia.org/wiki/Arecibo_Telescope):
|
| > The telescope had three radar transmitters, with effective
| isotropic radiated powers (EIRPs) of 22 TW (continuous) at 2380
| MHz
|
| Twenty. Two. Terawatts. Now, what that means in context is that
| if you were looking down the business end of that dish, it
| would be hitting you with as much RF as though you were
| standing the same distance away from a 22 TW regular dipole
| antenna. Put another way, it shines with the same brightness at
| dead ahead as a 22 TW antenna would show from any direction
| perpendicular to its length. Because the dish is highly
| directional, it's only that bright in a tiny angle covering a
| tiny fraction of the sky.
|
| If you're standing _behind_ it, nothing. In front of it? You
| turn into Dr. Manhattan.
|
| It's amazing.
| bobmcnamara wrote:
| Near field effects have got to be huge on those things.
| slow_typist wrote:
| A dipole does not radiate isotropically. It has a gain of
| 2.15 dB over the theoretical isotropic antenna. Gains with
| respect to the dipole are ERP, not EIRP. But still a lot of
| power :-)
| kstrauser wrote:
| Oops, you're right. That's still _really freaking bright!_
| 15155 wrote:
| I recommend watching the video series on YouTube re: the
| ISEE-3 Reboot Project before it's lost to history:
|
| https://www.youtube.com/@balint256/search?query=arecibo
| 1oooqooq wrote:
| https://www.youtube.com/playlist?list=PLPmwwVknVIiUlPbkfBUY
| 1...
|
| link that works on generic ytube clients like newpipe
| viraptor wrote:
| > If you're standing behind it, nothing
|
| Is there actually no back lobe on dishes that size? Or is it
| just extremely small?
| HPsquared wrote:
| I wonder what the EIRP is of a typical laser pointer (or a
| high-powered one)
| pavel_lishin wrote:
| > _While we have shown that we can use the Dwingeloo telescope to
| receive the carrier signal from Voyager-1, we cannot use the
| telescope to communicate with it. NASA uses dishes in the Deep-
| Space Network (DSN) to communicate with Voyager 1. These dishes,
| located around the globe in Goldstone, Canberra and Madrid, are
| optimized for these higher frequencies and have a diameter of
| 70m, much larger than the 25m Dwingeloo Telescope._
|
| I wonder if this was included as a "please don't ask us if we're
| capable of hacking it, we are _not_ " CYA.
| giantg2 wrote:
| Yeah, it seemed a bit odd. Like I would wonder if I could
| xommjnicste with it. But I would also know that could
| jeopardize the craft and is probably illegal in some way.
| dylan604 wrote:
| It's only a natural thought for people, if you can hear it, can
| you talk to it. So I don't see it as a CYA as much as just
| cutting off questions from people that know the intricacies of
| that kind of radio communication
| charles_f wrote:
| Pretty crazy to think that it's sitting like this in the open,
| with its old APIs all ready to be pentested. Secured by literal
| obscurity, introduced by a distance of a light day from the
| closest hacker.
| ragebol wrote:
| I think the obscurity is more due to the fact that reaching
| it with sufficient signal strength requires a big, big dish
| with a big, big amplifier.
| drmpeg wrote:
| Also, the exact uplink and downlink frequencies are not
| published.
| viraptor wrote:
| https://voyager.gsfc.nasa.gov/Library/DeepCommo_Chapter3
| --14... seems to include pretty specific up/down carrier
| frequencies and channels used.
| drmpeg wrote:
| I wonder why the frequency was redacted in this tweet.
|
| https://x.com/nascom1/status/1851789221885022416
| viraptor wrote:
| Maybe they're hiding the current Doppler shift? Or just
| trying to prevent noise from randos experimenting in that
| range?
| ElectRabbit wrote:
| They removed the frequencies from some of the more
| popular sites. That started during early stages of the
| Ukraine invasion.
|
| But it's still super easy to find them.
|
| Usually it takes a few hours until the sat ham guys find
| them and post spectrums.
| ElectRabbit wrote:
| The frequencies of most research satellites are all well
| known. But it takes more than 30 seconds of Googling.
| MoreMoore wrote:
| I'm more surprised that Russia or China haven't attempted
| to communicate with things like Voyager. Not necessarily to
| sabotage, but to find out as much as they can about it by
| interacting with it.
| ben_w wrote:
| At the time? Perhaps, I don't know when the design
| documents* became public.
|
| But today, Voyager 1 is a 50 year old curiosity, still of
| interest to cosmologists of course, but governments will
| be less interested in it than archeologists.
|
| * e.g.
| https://voyager.gsfc.nasa.gov/Library/VOY_library.html
| and https://ntrs.nasa.gov/api/citations/19660011758/downl
| oads/19...
| floren wrote:
| "HAM" of course stands for "HAM - Acronym? Maybe!"
| nerdile wrote:
| Glad to see someone else had the same reaction I did. There's
| no need to shout.
| dylan604 wrote:
| gotta love those recursive names. Stallman would be proud
| immibis wrote:
| I heard Stallman stands for Stallman's Toenails Are Likely
| Legitimate Methods of Acquiring Nutrition
| ForHackernews wrote:
| I'm not a radio geek. Maybe @dang can edit the title?
|
| Fully a third of the comments here are folks showing off their
| knowledge of non-acronyms.
| lnauta wrote:
| I got to visit the telescope earlier this year, its pretty cool.
| In a forest outside some small towns. For how well connected the
| Netherlands is, its pretty hard to reach.
|
| We looked at the sun and some planets in radio frequencies (its
| all radio astronomy with LOFAR nearby).
|
| That they can listen to Voyager with such an old instrument is
| incredible. It must help that the satellite is aimed at us.
| outworlder wrote:
| > That they can listen to Voyager with such an old instrument
| is incredible. It must help that the satellite is aimed at us.
|
| It is indeed incredible.
|
| Nitpick, but I'm not sure 'satellite' is correct in this
| context. Voyager is in a solar system escape trajectory.
| lnauta wrote:
| You may be correct. In my head anything shot into space and
| still flying must be a satellite but that's a lazy shortcut.
| ChrisMarshallNY wrote:
| The term that I always hear, is "probe."
| Cthulhu_ wrote:
| I wanted to joke that it's a solar sattelite but nope...
| Galactic center sattelite maybe?
| ggm wrote:
| I think you'd have to demonstrate that the forces on its
| motion were dominated by motion relative to the galactic
| centre more than other effects, to get there.
| dylan604 wrote:
| Why does its age come in to play? The think they are listening
| to is old too. The main thing is the size of the dish that
| allows for it, and then the skills of the operators to find the
| weak signal in the noise.
| SamPatt wrote:
| Stuff breaks. Keeping it functional for a long time is
| impressive.
|
| Arecibo failed to do so.
| lnauta wrote:
| Indeed, it has been decommissioned for some 20 odd years
| now. But it's kept up and running by volunteers and became
| a national monument.
| dylan604 wrote:
| What's been decommissioned for 20 years now? I'm not
| really sure where you get your information from, but it's
| clearly not correct.
|
| Decommissioned Announced November 19, 2020 Collapsed
| December 1, 2020
|
| https://en.wikipedia.org/wiki/Arecibo_Telescope
| cge wrote:
| They were referring to Dwingeloo [1] in the Netherlands,
| the telescope used in this article, not Arecibo. It
| stopped officially operating as a radio telescope in
| 2000, and has since been used for a variety of astronomy
| and amateur radio projects.
|
| [1]:
| https://en.wikipedia.org/wiki/Dwingeloo_Radio_Observatory
| 15155 wrote:
| Because the object you are receiving a signal from is
| further, thus necessitating more sensitive receiving
| equipment that couldn't have existed in the past?
| dylan604 wrote:
| I don't buy that premise at all.
| 15155 wrote:
| Superconducting detectors and materials science have
| obviously advanced leaps and bounds in the last 30 years:
| it's really not up for debate or a premise that can be
| "bought."
| dylan604 wrote:
| The implications is they were not able before. That's
| what I don't buy. You're stating the obvious while
| ignoring the inconvenient to your premise.
| spiderfarmer wrote:
| It's pretty much my backyard. I wonder what will happen to the
| WSRT when maintenance will inevitably become an issue.
| t0mas88 wrote:
| I think it was deliberately built in a more remote area to
| avoid interference from other signals? When I was a kid (25
| years ago :-)) I went on holiday in that area a few times,
| there were signs to tell people not to use radio equipment in
| the nature areas around the telescope.
|
| It's cool that they kept it operational for amateurs and
| education.
| Full_Clark wrote:
| > NASA uses dishes in the Deep-Space Network (DSN) to communicate
| with Voyager 1. These dishes, located around the globe in
| Goldstone, Canberra and Madrid, are optimized for these higher
| frequencies
|
| Madrid Longitude: 4.3deg W
|
| Goldstone Longitude: 116.9deg W
|
| Canberra Longitude: 149.0deg E
|
| 153.3deg from Madrid to Canberra and only 94.1deg from Canberra
| to Goldstone. Bit of a slight to Western Australia to skip over
| the ~120deg option and put the third dish in Canberra.
| bobmcnamara wrote:
| Some conspiracy theorists will tell you Goldstone is too close
| to Alice for that back then.
| brcmthrowaway wrote:
| I think theres a CIA base in the desert right?
| RajT88 wrote:
| Nah. Swamp gas reflecting the light of Venus.
| caf wrote:
| You may be thinking of https://en.wikipedia.org/wiki/Pine_Gap
| parsimo2010 wrote:
| Perhaps the Aussies didn't want NASA to mess with their dishes
| at Geraldton.
| https://en.wikipedia.org/wiki/Australian_Defence_Satellite_C...
| jen729w wrote:
| The Canberra dish is super easy to visit. Source: I live here,
| and have. :-)
| lizzas wrote:
| Doh! I lived there and been within 1km of it without knowing
| it!
| caf wrote:
| It's only just re-opened to visitors after an extended
| closure that began in the COVID times!
| Neywiny wrote:
| I'm surprised they can still get a positive SNR at those
| distances. Incredible
| smitelli wrote:
| I can't find the article at the moment, but my recollection is
| that it has been estimated that each symbol was carried in on a
| few hundred photons.
| Neywiny wrote:
| Yeah I think I saw that on HN too. I'm just surprised they
| can see something on the spectrum.
| kstrauser wrote:
| Does it have? You can still decode a signal with negative SNR:
| https://heungno.net/?p=4373
| consumer451 wrote:
| Ooo, sorry for the tangent, but this might be my chance to
| get a real answer for this. Can someone who really
| understands RF explain to me at what distance the concept
| behind this site breaks down, for a truly advanced
| technological species?
|
| https://lightyear.fm
| dearing wrote:
| If's fun to think that our Sirius tech cousins at the BBQ
| under a Texas sized parabolic dish aimed at Austin would be
| jamming Nelly's "hot in here".
|
| Over distance its about fighting the noise in between the
| source and the receiver while also fading because of the
| free space loss, think of a flashlight - not a laser. So
| nelly volume ticks down while the local stations ramp up..
|
| To keep your car jamming you'd build a growing antenna
| attached to your ford festiva that as you made your way
| would compensate for this loss by collecting more signal to
| focus back to a feed horn, a parabolic - like a larger
| magnifying glass focusing more ant burning heat in the
| winter versus the summer.
|
| Very roughly it seems it would be the size of Texas when
| you arrived at the BBQ, assuming you are traveling the
| speed of light and left in the early aughts.
|
| You wouldn't hear the song until you hit the break because
| its the frequency over time that pumps the jam.
| consumer451 wrote:
| > If's fun to think that our Sirius tech cousins at the
| BBQ under a Texas sized parabolic dish aimed at Austin
| would be jamming Nelly's "hot in here".
|
| OK, but a giant parabolic dish is some parochial 20th
| century Earth tech.
|
| I was imagining some little guys who create a 100 cubic
| AU grid of omnidirectional sensors, with a sensor every
| 1000km, all hooked up the mother of all DSPs. I can
| visualize that system identifying some pretty faint waves
| vibing in the noise. Am I wrong in thinking that this
| system could pickup AM radio really far away, easily...
| and once they got sick of that, even FM?
| dearing wrote:
| Each of the small detectors need to decern what is noise
| and what is not. They wouldn't know static from a station
| and having more clueless detectors wouldn't give you more
| any information in that regard.
|
| An AU cubic grid of detectors would inform you where a
| signal originates from by comparing free space loss over
| the area of the coverage. IF you could discern a station
| from static.
| consumer451 wrote:
| > Each of the small detectors need to decern what is
| noise and what is not.
|
| In my un-optimized imaginary system, the sensors are very
| sensitive and dumb, like me. All the difficult work is
| done by the central DSP-like brain that can identify even
| the tiniest of waves moving through the grid.
|
| The utility comes from seeing the relative values in the
| grid... a pattern of tiny changes in some arc, moving
| through the grid.
|
| Sure, killer triangulation (actually radial
| measurement?), but also possibly a decent 500 light-year
| AM tuner?
| dearing wrote:
| That's the game, more sensitive receivers receive more
| noise too. The game is sending something that will not
| look like the noise. The longer the sequence, the more
| likely to decode something but the slower the symbol rate
| (bandwidth)
|
| Imagine your array popped out SHORT-SHORT-SHORT-LONG-
| LONG-LONG-SHORT-SHORT-SHORT
|
| You just heard a morse code for SOS! The shorts where
| detected over 100Mhz (FM) +30db for 1 second each and the
| longs were 3 seconds each on a carrier that sites at
| +10db. That's amplitude modulation and that looks like
| intelligence but unless you knew morse code - it wouldn't
| make any sense.
|
| The further away you get from the source, the more those
| decibel spikes weaken and will eventually be no different
| than the noise floor. Your super computer with a billion
| ears, only hears ~static~.
|
| Try this, imagine instead if there was no free space loss
| in the electromagnetic field - we'd wouldn't be hearing
| humming but SCREAMS from all the noise sources from
| EVERYWHERE as if we were right next to them, forever. It
| would impossible to decern anything from anywhere.
| Communication is defined by its distance because signals
| have differing origins. Sensitivity, or lack there in, is
| a feature not a failure.
|
| Who's to say a quasar isn't just a lovely time clock for
| signals encoded in the noise and we haven't figured out
| what the breakpoint from noise is yet?
| prewett wrote:
| > Who's to say a quasar isn't just a lovely time clock
| for signals encoded in the noise
|
| Apart from a) quasars are broad-spectrum, not narrow
| frequencies (at least I assume that is the case), and b)
| the power required is too large for a civilization to
| realistically be able to generate. Not to mention that
| all that power is overkill for intragalactic
| communication.
|
| But it's a good sci-fi idea!
| immibis wrote:
| What I got is that SNR is relative to a time period. If you
| average the received signal over a longer period of time, the
| noise tends to cancel out but the signal tends to stack up
| (if the transmitter is still transmitting the same bit).
| Traditionally you'd use a narrower filter to remove more
| noise while keeping the signal, but today's (and last
| decade's and the decade's before that) fast computers can do
| part of the averaging in software, which leads to seeing a
| digital signal come in as noise, and then a signal magically
| appears after processing. This can also be done with CDMA
| signals provided that you're locked onto the timing of the
| code, which is something analog electronics can't do.
| Neywiny wrote:
| In the spectrum plot you can see a signal, and you can see a
| noise floor that's below the signal. So.... Yes? Does it not?
| I'm well aware of negative SNR signals like GNSS, but this
| doesn't look like that.
| gaze wrote:
| I know this is super nitpicky but Ham isn't an acronym. It's ham
| as in ham-fisted -- amateur radio.
| xattt wrote:
| I always thought it was because OG hams had some sort of
| regional accent and would say hamateur.
| gaze wrote:
| oh maybe. There's maybe multiple stories, but none of them
| that I've heard involve it being an acronym.
| dhosek wrote:
| It's because amateur radio operators also enjoy Serrano ham.
| LeoPanthera wrote:
| There's something about three-letter words with an A in the
| middle that make people assume they're acronyms. HAM and MAC
| (as in, Macintosh) are often incorrectly written that way. It's
| weird.
| verandaguy wrote:
| Mac might be a word, but MAC, MAC, and MAC are all acronyms,
| to say nothing of the cosmetics brand MAC (styled as M*A*C,
| though not M.A.C., and remains a word, not an acronym or
| initialism).
| inopinatus wrote:
| Mac is a valid abbreviation of the Macintosh, which is
| named indirectly after John McIntosh, a Canadian farmer and
| apple breeder of Scottish descent, who gave his name to the
| McIntosh Red cultivar. Scottish artist Charles Rennie
| Mackintosh was also born McIntosh but revised his family
| name after a spelling error at the Glasgow School of Art.
| The Mackintosh that you wear is similarly misnamed after
| Charles Macintosh (no relation), inventor of the modern
| waterproof raincoat. And so it goes.
| inopinatus wrote:
| An O appears to be a similar trigger. Our building manager
| persists in announcing the security tokens thus, as in, "Your
| new key FOB is ready.", and I feel real pain every time.
| adolph wrote:
| Just imagine saluting them and responding, "Very well; that
| will be all for now, Lieutenant. At twelve o'hundred we
| will head outside the wire."
|
| https://en.wikipedia.org/wiki/List_of_forward_operating_bas
| e...
| HPsquared wrote:
| GotoBLAS always gets me. Named after the developer,
| Kazushige Goto.
| Avicebron wrote:
| Medium Access Control (MAC) here in the protocol mines we use
| it pretty frequently
| cyberax wrote:
| Also Mandatory Access Control.
| msylvest wrote:
| And Message Authentication Code
| dingensundso wrote:
| And Macintosh Apple Comouter
| Scarblac wrote:
| Also ELO ratings for chess (named after Dr. Arpad Elo).
| patwolf wrote:
| Whenever I say Elo out loud, it takes a lot of mental
| energy to not say E-L-O, as if I'm talking about the
| Electric Light Orchestra.
| gsck wrote:
| LUA is the one that annoys me the most, its a word. Its moon
| in portugese
| nedrylandJP wrote:
| Or my boss letting us know there will be a TEAMS meeting.
| RF_Enthusiast wrote:
| Yeah, it doesn't stand for anything. It's just a bunch of
| Highly Advanced Messaging.
| dylan604 wrote:
| it Hain't AM
| dtgriscom wrote:
| Whoa: there's a fairly long WP article on this:
| https://en.wikipedia.org/wiki/Etymology_of_ham_radio
| MoreMoore wrote:
| Is WP a common abbreviation for Wikipedia? I usually just say
| wiki.
| anilakar wrote:
| Wikipedia is a wiki, but only one specific wiki is
| Wikipedia
| bell-cot wrote:
| "WP" looks like WordPress to me.
| biofox wrote:
| I thought Washington Post
| in12parsecs wrote:
| I am old enough to still see "WordPerfect"...from the
| 1980s.
| nedrylandJP wrote:
| Well, I am old enough to still see William Penn...from
| the 1680s.
| MoreMoore wrote:
| You don't look a day over 200.
| Cthulhu_ wrote:
| I'll have you know I learned typing in WP (word perfect)
| in the late 90's still.
|
| (I guess they preferred typing on DOS based systems even
| though windows 98 was mainstream by then since it meant
| you couldn't alt-tab and lose focus or cheat somehow? IDK
| know. Maybe it was a licensing issue)
| n_plus_1_acc wrote:
| It's a common inside wikipedia itself. For example, WP:POV
| is used to link to the "neutral point of view" meta page.
| beeskneecaps wrote:
| I had always heard "Hertz, Armstrong, and Marconi". 73!
| amatecha wrote:
| Interestingly that naming scheme is debunked on the
| adjacently-linked wikipedia page on the subject: https://en.w
| ikipedia.org/wiki/Etymology_of_ham_radio#Hertz%E...
| smelendez wrote:
| I've been seeing it capitalized more and more over the past
| decade or so. It grates for me as well but seems to be getting
| more common.
| vitaflo wrote:
| It's an easy way to tell that someone isn't a ham tho.
| Mountain_Skies wrote:
| Same for Mensa. I've never seen an actual member write
| MENSA but people who fake being members do it constantly.
| Think it might come from some of the organization's various
| wordmark logos being misinterpreted.
| RicoElectrico wrote:
| Probably capitalized by the HN's title auto-mangler.
| anothertroll123 wrote:
| TIL!!!!
| anothertroll123 wrote:
| Aw. I meant it in a good way...
| dang wrote:
| Ok, we've downcased the AM above.
| quux wrote:
| If I'm understanding this right, they were able to receive the
| carrier, but didn't demodulate any signal or decode any data?
| amatecha wrote:
| I wonder about that too, was it just only transmitting an
| unmodulated carrier at the time (minus 22 hours lol)? Or is the
| signal quality too poor to discern any modulation? Or something
| else? >_>
| thomas_tel wrote:
| We only see the carrier because it has such narrow bandwidth,
| the modulated data is for us not distinguishable from the
| noise. FYI, at this data rate the carrier contains 25% of the
| transmitted power.
| kqbx wrote:
| The article is light on details, but we can make some guesses
| based on the label "10s integrations, 1Hz channels" in the
| plot. I assume they have a bank of 1Hz filters, and they split
| the output of each filter into 10s intervals, and somehow
| combine ('integrate') each 10s chunk into a single number for
| each bin.
|
| They need to compensate the Doppler shift so that the signal
| stays in one bin over the 10s integration time. I imagine they
| are using non-coherent integration (basically computing total
| signal energy over 10s in each bin) to take into account that
| the doppler compensation is not perfect (if it was, you could
| have 0.1Hz bins with 10s integration time).
|
| If the above is true, then yeah, they can't demodulate any data
| because the integration time is much longer than symbol
| duration.
|
| I wonder if with more accurate Doppler prediction, you could
| get an ever longer integration time and narrower bins, and thus
| even bigger SNR gain, perhaps allowing signal detection with a
| smaller dish...
| thomas_tel wrote:
| The "live" plot (with the peak) uses indeed 1Hz bins (of 1
| second), that we average over the last 2-3 minutes to reduce
| the noise. We could go even narrower, I might give that a try
| on the recorded data.
| kqbx wrote:
| Thank you for the clarification. Recently I've been reading
| a lot about tracking of space objects (though much closer
| ones, on LEO/MEO), so this is some very interesting stuff
| for me!
| ijidak wrote:
| The fact that Voyager is far enough for light to take a day to
| reach us is mind blowing to me.
|
| And that our solar system is more than a light day in diameter is
| also mind blowing.
| greesil wrote:
| Neptune is at 30 AU, which is about 4 light hours. Double that
| to get the diameter.
| ijidak wrote:
| Apologies. I was referring to the heliopause.
| makmanalp wrote:
| > almost 25 billion kilometers
|
| Had to reread that a few times to make sure
| amatecha wrote:
| Rad. I was pretty stoked when I received signals from Australia
| and New Zealand ~12000km away, and later from the International
| Space Station (actually technically much closer lol). I can't
| imagine how damn cool it would be to pick up anything at all from
| a freakin' deep space probe some 25billion km away!!
| slow_typist wrote:
| Incredible achievement but would really appreciate if they laid
| out the details.
| teleforce wrote:
| > Since the Dwingeloo telescope was designed for observing at
| lower frequencies than the 8.4GHz telemetry transmitted by
| Voyager 1, a new antenna had to be mounted.
|
| Is there any info on this new antenna?
| ElectRabbit wrote:
| Have a look at Daniel Estevez blog. He's a regular user of bigger
| telescopes (like ATA) and managed to receive _and_ decode Voyager
| 1. He wrote a GNURadio decoder for it.
|
| https://destevez.net/2021/09/decoding-voyager-1/
| xhkkffbf wrote:
| It would be nice if some HAM operators or other citizen
| scientists could provide some evidence about the US moon landing
| that can be verified independently. One friend won't shut up
| about it and it grows tiresome.
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