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Radio Amateur Copies Signal from Mars-Orbiting Satellite
- myth2018 6y agoWow, I'm a ham radio operator and today during Perseverance landing I was wondering if it would be possible to receive signals from orbiters on Mars using homemade equipment. Now I have my answer.
- wrycoder 6y agoAnd his dish is only 60 cm dia.
- myth2018 6y agoThose 60 cm are probably enough for his requirements. It seems that he's mainly interested on detecting signal presence, but not necessarily demodulating it. Then, I suppose that the signal-to-noise ratio provided by his small dish is sufficient
- floatingatoll 6y agoI wonder if ARRL knows there’s malicious ads on their site. Reader mode saves the day!
- jackyinger 6y agoI can confirm that I got some sketchy stuff from this site. It showed me an I’m not a robot butting which I stupidly clicked. Went and cycled my passwords to be safe. Flagged the post as a result.
- rawoke083600 6y agoI'm pretty sure it's curse of HAM-Websites ! They either have malware or looks like frontpage2000 projects. Not dishing just noting ! Big fan of hams !
- zokier 6y ago> He uses a homemade 60-centimeter dish that seems surprisingly small. overall, impressive feat. would be interesting to know more about the gear. from the posted video, I guess he is using ettus b200, but thats just a guess.
- schoen 6y agoApparently the Deep Space Network dishes are (now up to) 34 meters: https://www.nasa.gov/feature/jpl/nasa-s-deep-space-network-welcomes-a-new-dish-to-the-family https://www.nasa.gov/feature/jpl/nasa-s-deep-space-network-w... I guess they achieve higher reliability than amateurs on a number of counts, but that contrast also makes the amateur efforts seem even more impressive. (Since area is proportional to the square of diameter, the DSN dishes would each be over 3,000 times larger than Scott Tilley's dish.)
- madengr 6y agoHe is detecting, not demodulating, which is what the big dishes are for. Most deep space comms have carrier leakage (on purpose) for ranging. That’s likely what he is detecting.
- myth2018 6y agoIndeed, but there are other important factors besides size. DSN have way bigger requirements in terms of signal to noise ratios, since they need to demodulate received signals. Scott Tilley, on the other hand, seems to be mainly interested on detecting the presence of signals, not necessarily extracting information from it. Then, he could build a bigger dish, but he doesn't actually need one to achieve his goal. I notice that another guy commented here about that. His comment is dead now, but he had a point. I found it informative indeed, I've always asked myself why spacecrafts "wasted" energy with carriers and never realized they make the signal easer to find.
- schoen 6y agoThanks for that clarification (to you and the author of the dead sibling comment)!
- emptybits 6y agoCool. This Canadian amateur, Scott Tilley VE7TIL, is the same operator behind previous discoveries like a NASA satellite thought to be dead three years ago. https://www.rac.ca/amateurs-in-the-news-scott-tilley-ve7til-finds-resurrected-nasa-satellite/ https://www.rac.ca/amateurs-in-the-news-scott-tilley-ve7til-...
- geocrasher 6y agoThis is nothing short of incredible. Radio is hard, even at HF (1-30mhz). It's very forgiving at HF though, and so is very approachable. This is where I spend my ham radio time dabbling and hacking away at things. VHF is harder, and UHF an order of magnitude harder. But 8-12Ghz? That's not for mere mortals. It's machining pieces at tight tolerances and movement measured in the smallest fractions. If this is what he does for fun, I wonder what he does for work?
- myth2018 6y agoI have no hands-on experience with homemade equipment for the GHz bands, but I've read that they are a bit less challenging than it seems at a first glance. Mostly because of the availability of GPS receivers providing highly stable, relatively cheap frequency references for transverters. Notice that I'm not saying this to demerit any achievement. My intention here is to be encouraging in case you intend to give it a try. A similar setup could allow you to operate moon bounce (CW and FT8 seems to be pretty active) and also work the Es'hail-2 geostationary satellite in case you're in range. So it's definitely a very promising field to invest in.
- texasbigdata 6y agoAs an outsider what’s the order of magnitude on humans that have this setup currently functional? 100? 1,000? Etc.
- DrAwdeOccarim 6y agoThere are 774,562 amateur radio licensed people in the US [1]. I would assume 10% of them are super active, so 77,456, and of those super active people, I'd say 1% of them are pushing the boundaries. So 1000? [1] http://www.arrl.org/fcc-license-counts http://www.arrl.org/fcc-license-counts
- texasbigdata 6y agoThis comment is amazing. Thank you so much.
- hoppla 6y agoIs the arrl website hacked? Whenever I click on text, I get ad pop ups.
- testaaajxjd 6y agoYes this website has been hacked...
- testaaajxjd 6y agoI think it got in due to the ads.. I've reloaded the page and it doesn't hijack the links anymore.
- topbanana 6y agoIf anyone's interested in getting started with space signals, check out AMSAT. https://www.amsat.org/ https://www.amsat.org/
- deleted 6y ago[deleted]
- testaaajxjd 6y agoWarning: I think that sometimes this page loads malicious ads that hijack the links on the pages.
- treesknees 6y agoAs someone not familiar with ham - what can you do with this signal? Can you decode it to view stats or pictures? Or is it mostly just "hearing" it speak to Earth? I'm also curious what prevents say an amateur operator or even another country from sending commands or disrupting communication to remote systems on Mars. Is it the just the amount of work they'd have to do, proprietary/secret protocol, encryption?
- lebuffon 6y agoThe amateur radio frequencies that are "legal" for a ham operator to transmit on are well defined. If the NASA devices used Amateur frequencies for commercial work I believe they would be breaking US law as well. So the terms of the amateur license prohibit transmitting signals to the remote systems on Mars. The practical requirements of getting a strong enough signal to Mars would require a big dish to focus the energy and some high power microwave equipment which make it more difficult but not impossible given enough resources. Then as you mentioned one needs to know the communication protocols. BTW there were Ham built satellites in orbit, that piggybacked onto other missions. (OSCAR) Not sure if they are still in orbit. And again they used reserved spectrum for licensed experimental Amateur radio stations.
- weezer 6y agoWhat you said is mostly true but there are also frequencies that ham operators can transmit in, but only have secondary priority to other uses. For example hams can only transmit in the 1.25 meter band if they don't interfere with other users like the Automated Maritime Telecommunications Systems (AMTS). https://hamradioprepper.com/us-amateur-radio-bands/ https://hamradioprepper.com/us-amateur-radio-bands/
- myth2018 6y agoMy two cents in addition to lebuffon's reply: The occasional amateur gear is usually not enough to demodulate signals from Mars, since they're too faint. You'd need much larger dishes to, roughly speaking, "ingest" more energy into your receiver so that it become more distinguishable from noise and you can extract information from it. It would be possible to demodulate with smaller, amateur dishes if the spacecraft transmitted in a very narrow bandwidth. It wouldn't make sense for space agencies to do that, though, since they would trade higher bit rates for cheaper receivers, whilst powerful receivers aren't that difficult to build and are totally on budget for an agency capable of launching a spacecraft. But I must say that that would be a very nice citizen science project.