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Receiving Weather Satellite Images With An £8 Dongle
- RobotCaleb 11y agoI did this a few years ago with a similar dongle and a homemade antenna. It's a pretty cool thing to see something you cobbled together receiving real-time messages from space. http://robotrising.org/2012/10/capturing-weather-satellite-images-using-a-homebrew-antenna/ http://robotrising.org/2012/10/capturing-weather-satellite-i...
- nly 11y agoLast thing I used my R820T for was decoding POCSAG[0] messages here in the UK. It's a paging system, and the messages seem to be broadcast nationwide in the clear. Seems to be mostly used by the NHS and vets. I got kind of depressed reading about dying pets. [0] https://en.wikipedia.org/wiki/POCSAG https://en.wikipedia.org/wiki/POCSAG
- Fizzadar 11y agoThis is awesome; am ordering a dongle right away! Did some digging and there's a whole load of things which can potentially be picked up, including dead satellites [0]. RTL-SDR.com has a whole load of awesome looking tutorials [1]. [0] http://www.rtl-sdr.com/receiving-dead-satellites-rtl-sdr/ http://www.rtl-sdr.com/receiving-dead-satellites-rtl-sdr/ [1] http://www.rtl-sdr.com/category/tutorial/ http://www.rtl-sdr.com/category/tutorial/
- misnome 11y agoAlso just ordered one. This is the best HN thread I've seen in ages!
- xur17 11y agoI just ordered one too - this looks awesome. You can track aircraft (newer airplanes broadcast their locations, ships, etc. This [0] is the one I ended up ordering, I just wish one day shipping was available. [0] http://www.amazon.com/dp/B009U7WZCA http://www.amazon.com/dp/B009U7WZCA
- dima55 11y ago$20 is way too expensive for these. Here's the same thing for half the price: http://www.ebay.com/itm/Newsky-TV28T-v2-USB-DVB-T-RTL-SDR-Receiver-RTL2832U-R820T-Tuner-MCX-Input-/131532641773?pt=LH_DefaultDomain_0&hash=item1e9ff4d5ed http://www.ebay.com/itm/Newsky-TV28T-v2-USB-DVB-T-RTL-SDR-Re...
- gPphX 11y ago£4.62 = $7.16 http://www.ebay.com/itm/171749696878 http://www.ebay.com/itm/171749696878 £6.96 = $$10.80 http://www.ebay.com/itm/131532641773 http://www.ebay.com/itm/131532641773 ebay search : RTL2832U R820T -Connector -Adapter -Angle
- TD-Linux 11y agoThere are a variety of factories producing these at variable quality. I'd still recommend the Nooelec version if you have the budget to spare.
- kseistrup 11y agoDX has some cheap RTL2832U based dongles ⌘ http://eud.dx.com/search/RTL2832U http://eud.dx.com/search/RTL2832U
- fnordfnordfnord 11y agoI recommend an [antenna port] to BNC or other adapters as well.
- j45 11y agoThis is the kind of cool Hacker News I like to see! Ordered.
- fosk 11y agoI would expect the communication to be encrypted, or is it supposed to be open to the outside world?
- nitrogen 11y agoI think weather satellites were meant to be useful to everyone who could receive the signal.
- fnordfnordfnord 11y agoEspecially for marine traffic.
- dzhiurgis 11y agoWeatherFax has been used for decades now. This, however, wouldn't be of much use in a regular cruiser as you do not want to keep your laptop constantly to wait for broadcast. Dedicated devices are quite cheap and reliable.
- fnordfnordfnord 11y agoI think most people are doing this for fun. But if you needed it and couldn't get your hands on the real thing, adding an Rpi and a screen to it makes a functional substitute.
- detaro 11y agoHigher quality images are encrypted, but the basic stuff is open.
- danielvf 11y agoThere are actually several vastly higher res weather broadcasts that are in the clear - they are just more work to receive. Search for LRPT and HRPT.
- kenrikm 11y agoYou can use the same dongle to tap into ADS-B signals to get realtime ATC and display it on a map. Also, it's interesting to just sit and listen to SFO ATC audio channel.
- robterrell 11y agoHe has a screenshot of this in the article.
- jodrellblank 11y agoThere's a Reddit for software defined radio, using the cheap Realtek RTL2832U devices. https://www.reddit.com/r/rtlsdr https://www.reddit.com/r/rtlsdr
- adestefan 11y agoJust be aware that some of the moderators have iron fists and like to go ban happy.
- olympus 11y agoThe author mentions that he used "A 2 metre bit of wire jammed in the screwhole at the base of the tiny antenna" to try and get better reception. While the signal he is receiving is in the 2-meter band, a monopole antenna works better if it is 1/4 the wavelength, so he might actually get better reception with a 0.5 meter length of wire. What he created is usually called a "random wire" antenna, and may deliver acceptable performance with a strong signal. But the NOAA satellites (and quite a few other satellites) use a circularly polarized signal, and for just a tiny bit more money (perhaps the cost of the dongle) you can make a MUCH better antenna for circularly polarized signals. Some designs are just helixes made with coax cable, some are just a couple of wires in an x-shape. Google is your friend, and building an antenna is a fun cheap weekend project and will greatly enhance your results when hunting for satellite signals. P.S. if you make a circularly polarized antenna and you discover that you made a LH polarization instead of the RH that you wanted (or vice versa), just turn the antenna upside down. It may behoove you if you are planning on listening to signals with both polarities to construct one that is easily flipped over.
- weinzierl 11y agoWhile the signal he is receiving is in the 2-meter band, a monopole antenna works better if it is 1/4 the wavelength, so he might actually get better reception with a 0.5 meter length of wire. I always thought a lambda/4 antenna is used because it's almost as good as a lambda antenna but much more conveniently to handle. I understand that more complicated antenna designs can be better than a simple lambda wire, but how can a lambda/n wire be better? I don't doubt what you are saying, I'm just curious how this can work.
- aexaey 11y agoLinear monopole antennas are very easy to reason about. Imagine (or actually draw) a sine wave graph, and then fit your antenna along the X axis of the graph. Now look at "signal" amplitude at the antenna's extremities. You'll notice that 1/4 wavelength antenna will give you the strongest signal, while 1/2 and full wavelength will apparently give no signal at all. The only reason that full-wavelength piece of wire picks up anything at all are build imperfections - wire length not perfectly matched to wavelength, not perfectly straight, not perfectly aligned with signal source, signal reflections hitting it from different angle, etc. Thats why olympus refers to performance of full-wavelength piece of wire as "random piece of wire"-kind of performance. On the other hand, linear dipole would be 1/2-wavelength (or 2 times 1/4-wavelength), as it is just two 1/4-monopoles put together.
- MrBra 11y agoGreat, just recently I became passionate about anything relating to radio theory and transmission and I had learnt about these dongles and was ready to get one. But before that, I decided I wanted a proper "hardware radio", and bought myself a portable wide band radio receiver [1] (great value for the price, I advice it). Then when I was about to get one of these dongles, as usual and as for the above radio, I got sucked into the reviews suggesting this or that other model for better sensitivity or extra features. Now I understand the price range for these cheap sticks is just in the order of a few tenths at maximum, but maybe there is a chance anyone has investigated a bit more on the available choices already? For example.. the one that has been written about in the article has 4 stars and 159 reviews while the first alternative in the "Amazon recommends" box has some 940 reviews and same 4 star score for just £ +2 (but I'm not even sure they do exactly the same things.. sorry). So, just wondering, maybe someone has already gone through this search and can recommend the best one to get? [1] http://www.amazon.com/Tecsun-PL-660-Portable-Shortwave-Single/dp/B004H9C4JK http://www.amazon.com/Tecsun-PL-660-Portable-Shortwave-Singl...
- olympus 11y ago> Now I understand the price range for these cheap sticks is just in the order of a few tenths at maximum, but maybe there is a chance anyone has investigated a bit more on the available choices? Thanks to the popularity of this family of DVB dongles, all the information you need is right here: http://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/ http://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/ Also look into the Funcube dongle for a sdr dongle that is designed for ham radio and not just an adapted DVB dongle -- they are pretty much the same thing though. If you can find an E4000 dongle on ebay it's probably worth twice as much as the R820T dongles because it gives you a wider frequency range. I have an R820T dongle and it works just fine though. One thing to keep in mind is that these dongles only have 8 bit ADCs in them, so no matter how great your signal path, you will top out at ~48db of sensitivity (rough formula is sensitivity in db = 6*bits of ADC). A "real" SDR like the USRP B210 has a 12 bit ADC in it, which means that it will top out at around 72db of sensitivity. Plus, spending the big money means that you will get a radio that takes less shortcuts than a cheaply produced dongle, so you are much more likely to get closer to that theoretical peak. But certainly start with a dongle, and play with it and see how far you get before you "absolutely need" some TX capability or have truly maxed out what you can do with only USB 2.0 and 8 bits of resolution (though there is a guy who was passively tracking aircraft with FM radio stations and two synchronized dongles so what you can do with these is pretty crazy).
- weinzierl 11y agoThere is also OsmocomSDR[1] which is an excellent starting point into software defined radio. [1] http://sdr.osmocom.org/trac/wiki/rtl-sdr http://sdr.osmocom.org/trac/wiki/rtl-sdr
- MrBra 11y agoHow does this one differ?
- jafingi 11y agoThat's totally awesome! Have to try this myself.
- SoulMan 11y agoAll I have done till now is tune to local FM stations. I would like to tune to AM SW stations all over the world. I think buying a 50 USD RF up converter is the only option ?
- dkozel 11y agoYou can do a very simple, though somewhat permanent, modification to the dongle and receive DC-14MHz. http://www.rtl-sdr.com/rtl-sdr-direct-sampling-mode/ http://www.rtl-sdr.com/rtl-sdr-direct-sampling-mode/
- userbinator 11y agoThere's a software modification here which is also interesting: http://superkuh.com/rtlsdr.html#directsample http://superkuh.com/rtlsdr.html#directsample The whole idea of the community figuring out hacks to use this hardware in ways that were never intended by its original designers, including exploiting bugs/artifacts, reminds me of the demoscene.
- amelius 11y agoI don't understand these signals are not encrypted, for commercial reasons.
- kintamanimatt 11y agoIt's not a commercial service, but a government one. The NOAA (National Oceanic and Atmospheric Administration) satellites belong to a department of the US government.
- amelius 11y agoIn many countries, public transport is run by the government, but still costs money. Governmental does not have to be orthogonal to commercial.
- bjelkeman-again 11y agoIn Sweden the agency that deals with cartography and land measurements (Lantmäteriet) charged money for their data. An acquaintance who works with the government checked their income and where it same from. Something like 80% came from other government departments and the rest from companies. But the extra 20% was roughly the cost of running the administration to manage the billing. So the data got limited use for no financial gain. In May they started releasing the maps under Creative Commons [1]. Not only me was really excited about this here in Sweden. [1] in Swedish http://computersweden.idg.se/2.2683/1.616018/slapp-kartorna-loss-det-ar-var--lantmateriets-databas-ute http://computersweden.idg.se/2.2683/1.616018/slapp-kartorna-...
- rsaxvc 11y agoSave for certain privacy concerns, data collected through public funding should belong to the people who funded it.
- jdietrich 11y agoWith a few exceptions, any content created by the US federal government is in the public domain. https://en.wikipedia.org/wiki/Copyright_status_of_work_by_the_U.S._government https://en.wikipedia.org/wiki/Copyright_status_of_work_by_th...
- ma5ter 11y agodone this few years ago http://imgur.com/a/3GELZ http://imgur.com/a/3GELZ
- dm2 11y agoFree fast shipping: http://www.ebay.com/itm/251240985308 http://www.ebay.com/itm/251240985308 Most of them seem to have the same two chips in them, RTL2832U and R820T. Does anyone see an issue with this item I linked to? Some people were mentioning quality issues with generics.
- fsiefken 11y agoNice hack! I wonder what other useful common digital signals can one record with a dongle? Time and date, teletext (which includes weather forecasts and news) I am aware of. There is also project Lantern & Outernet which might deliver 20 MB of data to all continents through nanosats next year. What other digital signals are transmitted?
- yardie 11y agoI did something similar using the same libraries and all using a Raspberrypi and DVB-T dongle [1]. Then I configured the tcp server, rtl_tcp to forward the packets to my workstation. This allowed me to put the Pi in a location more suited to receive transmissions, i.e. not next to RF emitting servers and power supplies. Then, using Gqrx with remote server, I analysed the results. [1] https://www.joechin.com/raspberry-pi-and-sdr-getting-started/ https://www.joechin.com/raspberry-pi-and-sdr-getting-started...
- robertduncan 11y agoLooks like your SSL certificate has expired.
- exo_stack 11y agoI wonder if that would work on a commercial jet @ 30K feet. Would be an interesting test.
- grkvlt 11y ago- https://twitter.com/grkvlt/status/600998588475375616 https://twitter.com/grkvlt/status/600998588475375616 This is the output I got on a flight from EDI to LHR at about the half-way point, decoding ADS-B transmissions.
- joushx 11y agoI have this one: http://www.nooelec.com/store/sdr/nesdr-mini2-rtl2832u-r820t2.html http://www.nooelec.com/store/sdr/nesdr-mini2-rtl2832u-r820t2... I already received aircraft positions (ADS-B), aircraft radio, ACARS, VDL, HFDL, satellite pictures, ISS pictures, a ISS astronaut speaking, a bunch of other satellites (including radio pirates on US military sats), small outdoor weather stations, a portable radio for children, some AM radio stations, a lot of ham radio and pagers. There is also huge amount of signals I can't decode yet.
- joushx 11y agoBTW: I'm using an old TV antenna.