[HN Gopher] WebSDR - Internet-connected Software-Defined Radios
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WebSDR - Internet-connected Software-Defined Radios
Author : nickt
Score : 247 points
Date : 2023-10-26 22:00 UTC (1 days ago)
(HTM) web link (www.websdr.org)
(TXT) w3m dump (www.websdr.org)
| riffic wrote:
| it's still closed source software?
|
| previously: https://news.ycombinator.com/item?id=18571139
| ianburrell wrote:
| It is closed. There is a lot of ham radio software that isn't
| open source. And a lot of open source isn't developed openly.
| You would think that all of it would be open source but I think
| a lot of hams didn't come from software world.
| mwbajor wrote:
| Take a look at gnuradio.
| JWLong wrote:
| There's quite a bit of overlap, actually. For some reason all
| of the old hams want to do .NET applications, though.
|
| I really think this is one of the reasons for the stagnation
| in the field.
| galangalalgol wrote:
| What would people want this to look like? Is there a
| backlog anywhere of stuff people would want?
|
| Edit: I was thinking maybe something that reads from an rtl
| or airspy, or maybe soapy? Then takes requests for channels
| over websockets from a wasm front end, then have the demod
| wasm side? And a waterfall streamed as a video to aid in
| making the channel selection? It would save bw to put demod
| server side, but this way clients could use custom demods
| if they want.
| reactordev wrote:
| The perceived stagnation in the field is because you
| can't multiplex an SDR stream. One user can control the
| radio at a time. You can not listen on more bands than
| your radio can receive at once. Capping out at 192hz band
| audio sampling on most hardware. Which means you can read
| a wide signal but you can only read one area of the
| spectrum at a time.
|
| You would need more radios. If you added more radios you
| would need antenna that worked across the various bands
| people would want to listen in on. Those can create
| "cross-talk" to other antenna close-by. There's not a
| simple solution to this. Nor does the novelty of it
| warrant solving this problem.
|
| I think something like FlightAware where users sample
| their own radios at frequencies and submit them to a
| service that can aggregate the spectrum in real-time is
| the only real way to provide a web-based "tune to any
| radio frequency" SDR.
| galangalalgol wrote:
| An airspy can digitize 12MHz of bandwidth at once. Even
| without a gpu you can spit out easily over a dozen
| digitally subtuned channels. The bandwidth for all that
| raw signal data going out would be the problem. Only one
| person can control where that 12MHz is centred, but
| people can pick where in it they want to listen just like
| they do with websdr now.
| reactordev wrote:
| Damn! Yes, you would need to have one user center the
| spectrum read and you can mux the output to users wanting
| specific bands but I had no idea an airspy had such a
| wide audio capture.
|
| Edit: I looked it up. You are indeed correct. 10MSPS IQ
| output. 10Mhz panorama spectrum view. That's ridiculous!
| I just bought one.
| galangalalgol wrote:
| I think the boxy one, the r2 not the mini, had some hacky
| way to get 80msps but it didn't specify how that made it
| over usb or why that wasn't the normal operational mode.
| mikewarot wrote:
| Even a $30 RTL-SDR dongle can record 2Mhz of bandwidth
| reliably. I've recorded hours of signals just in case it
| sometime later becomes interesting, and it all lives in a
| little corner of my hard drive.
| reactordev wrote:
| To add color to this. The reason being is because a lot of
| the old C++ libraries and code no longer function so
| pushing for .NET applications helps bring them into the
| 21st century. Also, I think it's more because of the fact
| that C# is very familiar to C/C++ developers. However, I
| believe the true target architecture should be Linux and
| there's some work in this area. GNU Radio, Gqrx,
| Qradiolink.
|
| It just depends on where you are looking. There's plenty of
| OSS for SDR (it's in the kernel, btw) on Linux. Windows
| you're going to get closed source 80% of the time. Mac,
| forget about it.
|
| -Old Ham
| weissbier wrote:
| If you want to have something similar for use at home, you
| could take a look at http://kiwisdr.com.
|
| I have one, but you need to hunt down EMI sources, before you
| can properly use it.
| madengr wrote:
| I have one too, on an active magnetic loop, which does a
| decent job of nulling near field interference.
|
| http://kiwisdr.lounix.net:8073/
| 65a wrote:
| You can also use high-Q antennae, if you have a frequency of
| interest. For instance, on HF (shortwave) a tunable small
| loop antenna does a whole lot better than a wire antenna in a
| high-random noise environment. You may still end up chasing
| down various bogies, but a lot of them can be blocked with
| the directionality of the antenna or the filtering properties
| of the antenna (higher Q antennas are more narrowband).
| nomel wrote:
| > but you need to hunt down EMI sources, before you can
| properly use it.
|
| Do you have any recommendations for doing this? I have some
| source that interferes every 11 seconds for a second or so.
| It causes packet loss with my wifi (2.5 and 5GHz), and makes
| my bluetooth game controllers really frustrating to use,
| since input are missed every time it does it. I assume it's
| in the microwave range.
|
| I'm familiar with RF test equipment, and I've thought about
| renting a spectrum analyzer, but I assume there's maybe some
| cheaper way.
| mikewarot wrote:
| You could get an rtlsdr dongle cheap and use it as a
| spectrum analyzer. There are command line utilities for
| that task in with the drivers online.
| 1317 wrote:
| they don't go up to the 2.4/5Ghz range though, they max
| out at about 1.7
| mikewarot wrote:
| Yeah, but it seems he's got a broadband noise source,
| likely the 2.4 Ghz is a harmonic of something that is
| within their range.
| throwaway914 wrote:
| The limited availability of KiwiSDR's have made it crazy high
| priced. I've been trying to get one for a year now but
| they're up to like $600 on aliexpress. KiwiSDR2 has been
| announced, but that's a ways off from being sold.
|
| WebSDR on other hardware is a better alternative-ish.
| rlex wrote:
| for open source alternative take a look at
| https://www.openwebrx.de/
|
| Can also demodulate digital modes (DMR, YSF, etC) and it have
| nice, modern UI.
|
| WebSDR have a weird list of requirements if you want to get
| install file - should open instance to public, provide lots of
| info, etc etc etc. It's not just closed-source.
| imroot wrote:
| I thought that it couldn't demodulate DMR and other modes
| unless it had the hardware to do so. Feel free to correct me
| if I'm wrong, though.
| snvzz wrote:
| DMR can definitely be handled by software.
|
| I have done this with a crude rtl-sdr stick.
| rlex wrote:
| You definitely can, but legality of such procedure is
| questionable. DMR uses AMBE codec, which require licensing
| from DVSI, but you can find open-source implementation on
| github (mdelib, jMBE). Projects such as DSD-FME[1], which
| allows you to decode much more than just DMR (P25, NXDN or
| SDRTrunk[2], which allows you to listen to trunking systems
| (p25, dmr tier 3 and much more) uses software
| implementation. OpenWebRX users software decoder too
| https://github.com/jketterl/digiham
|
| [1] https://github.com/lwvmobile/dsd-fme
|
| [2] https://github.com/DSheirer/sdrtrunk
| nickmcc wrote:
| I use https://github.com/jketterl/openwebrx with RTL-SDR sticks
| kareiva wrote:
| Try the fork at https://github.com/luarvique/openwebrx/
| grendelt wrote:
| _Years_ ago I made a couple of SoftRock receivers for the 20m and
| 40m CW bands and put them on a couple of Raspberry Pis. I got
| WebSDR to run on it and it 's kinda become a thing now.
|
| https://n5dux.com/ham/raspberrypi/websdr.php
| westurner wrote:
| From the WebSDR FAQ:
|
| > Q: _My SDR can be tuned from 0 to 30 MHz (or from 25 to 1900
| MHz, or whatever). Can I offer all of that tuning range to the
| users?_
|
| > A: _No. Such an SDR does not feed the entire 0-30 or 25-1900
| MHz spectrum to your computer: that would be way too much data.
| Instead, a small part (at most a few MHz) are filtered out in
| external hardware, centered around some frequency that you can
| tune. With the WebSDR software, users can only tune around
| within that small part of the spectrum. You (as the operator of
| the site) choose the centerfrequency_
|
| Rydberg antenna range: 0-20Ghz,
| https://news.ycombinator.com/item?id=28402527
| https://en.wikipedia.org/wiki/Rydberg_atom
|
| Bus width:
|
| W3C WebUSB enables USB device access from JS, TypeScript,
| WebAssembly, and anything that emscripten emcc can compile to
| WASM (for use with the in-browser WASM runtimes, or the newish
| docker WASM runtime CLI arg). Emscripten-forge is one way to
| build WASM WebAssembly from e.g. C, Python.
|
| W3C WebRTC specifies audio/video/message relaying and NAT
| traversal: https://webrtc.org/getting-started/media-devices
|
| OpenWRT has an rtl-sdr package but not yet a WebSDR package;
| and an nginx-ssl package, but there's not yet an nginx-rtmp-
| module package fwics: https://www.google.com/search?q=nginx-
| rtmp-module+openwrt
|
| OpenWRT wiki > SDR, LoRA / LoRAWAN , Mesh
| https://openwrt.org/docs/guide-user/advanced/sdr ,
| https://www.google.com/search?q=openwrt+lora
|
| Pipewire may now arguably be the best way to handle audio and
| video streams with Linux. Pipewire is not yet supported on
| OpenWRT ? but is probably already supported by DragonOS
| (Lubuntu 22.10+)?
|
| Pipewire: https://en.wikipedia.org/wiki/PipeWire
| https://wiki.archlinux.org/title/PipeWire
|
| https://news.ycombinator.com/item?id=30613125 ... Pipewire to
| WebRTC:
|
| pipewire-screenaudio: https://github.com/IceDBorn/pipewire-
| screenaudio:
|
| > _Extension to passthrough pipewire audio to WebRTC
| Screenshare_
|
| awesome-amateur-radio#sdr https://github.com/mcaserta/awesome-
| amateur-radio#sdr
|
| The OpenWRT wiki lists a few different weather station apps
| that can retrieve, record chart, and publish weather data from
| various weather sensors and also from GPIO or SDR; pywws, weewx
|
| weewx: https://github.com/weewx/weewx
|
| A WebSDR LuCI app would be cool.
|
| LuCI docs > Modules:
| https://github.com/openwrt/luci/blob/master/docs/Modules.md
|
| SETI + Unistellar => all cool things:
| https://www.seti.org/unistellar-and-seti-institute-partnersh...
| https://www.seti.org/unistellar-seti-institute-education
|
| https://www.unistellar.com/citizen-science/ :
|
| > Citizen Astronomer Network: _The Unistellar Network is a
| worldwide community of Citizen Astronomers working in
| partnership with professional astronomers at the SETI
| Institute. Members use their Unistellar telescope to collect
| astronomical data, which is supplied to SETI Institute
| astronomers who then use it to develop predictions and models_
|
| "Synthetic aperture": https://en.wikipedia.org/wiki/Synthetic-
| aperture_radar
|
| "WebUSB Support for RP2040" that has 2x20 pin (*) GPIO and
| MicroUSB: https://news.ycombinator.com/item?id=38007967
|
| A radio _telescope_ attached to a 30 pin Model B could probably
| also feed WebSDR?
| superkuh wrote:
| >Rydberg antenna range: 0-20Ghz,
| https://news.ycombinator.com/item?id=28402527
| https://en.wikipedia.org/wiki/Rydberg_atom
|
| Actually the instantaneous bandwidth of a ryberg antenna
| based receiver is only about ~4 MHz in implementation papers
| I've read. A good fit for a 2 MHz instantaneous banwidth $20
| rtl-sdr dongle. The 0-20 GHz is the tuning range (again).
| desertraven wrote:
| This is a cool project.
|
| I bought both a HackRF and an Ettus USRP B210 years ago for
| playing with.
|
| I am yet to actually do anything of interest! Anyone want to
| share anything cool they've done in the SDR world?
| op00to wrote:
| I have a pm2.5 sensor that hooks to a weather station I don't
| have. I am using a cheap SDR to grab the data over the air and
| dump it into a mqtt topic for consumption in home assistant.
| Standing on the shoulders of giants and all, but it's still
| pretty neat.
| ge96 wrote:
| Not me but this was neat and interesting (after using SDR to
| capture)
|
| https://www.youtube.com/watch?v=EFLvHMJ5PHk
| heywire wrote:
| I use rtlamr to receive and record my natural gas usage, and I
| wrote some code to receive my water usage from my water meter
| (though I've since moved that code to an Adafruit Feather w/ an
| RFM69 module).
| jcims wrote:
| Those are both extreme overkill for the task but participating
| in ADSB networks for sites like flightradar.
|
| I really enjoyed making antennas and capturing data from
| satellites.
|
| Getting trunking receivers (eg unitrunker) to listen to local
| first responder radio.
|
| Decoding pagers is fun
|
| As others have said, decoding various devices that talk on the
| various ISM bands is interesting.
|
| Just band surfing at night is a lot of fun imho. Finding random
| signals and trying to figure out what they are is cool.
| mikewarot wrote:
| I put together a VOR navigation receiver in a GNU Radio
| flowgraph. It was cool driving around the local beacon and
| having it point the right way as I moved.
| jjwiseman wrote:
| Love that. Curious what kind of range did got (I assume not
| great).
| mikewarot wrote:
| I never tested it, I was just happy to get it working.
|
| If I were to do it over, I'd likely want to optimize things
| quite a bit to get the sensitivity up.
|
| The amazing thing is, though the RTL-SDR dongles are only 8
| bit devices, when you're down-sampling 2Mhz of them to
| audio frequencies, you gain quite a few bits of resolution.
| I routinely pick up signals below the quantization
| threshold.
|
| I wonder what the lower bandwidth limit truly is, assuming
| a stable reference clock.
| hoppyhoppy2 wrote:
| I run a local Fire/EMS scanner feed for my county so people can
| listen in without a scanner or SDR of their own. It uses a
| bunch of directional antennas in the attic for best reception
| (I can't put up a giant mast antenna) connected to a bunch of
| Nooelec rtl-sdr dongles.
|
| Unlike a traditional scanner which only monitors one frequency
| at a time, if two things are happening simultaneously then you
| hear them both. This would be annoying or unlistenable in a
| busier area, but in my area it works fine.
| t_sea wrote:
| Interesting how many are clustered in Utah
| _whiteCaps_ wrote:
| If you're looking for chatter, check out https://pota.app and
| filter by SSB. You'll hear people making contacts for the Parks
| On The Air program.
|
| 10m (28MHz) has great propagation right now during the day so
| you'll hear people talking across great distances, like
| California to Japan or Australia.
| deltasepsilon wrote:
| For those interested in SDR, there was recently a discussion here
| on signals identification [1], and some months ago a discussion
| of NXP's new LA9310 ADC chip for radio applications [2]:
|
| [1] https://news.ycombinator.com/item?id=37869534
|
| [2] https://news.ycombinator.com/item?id=35325165
| 6312783123 wrote:
| Sadly the LA9310 DSP instruction set is considered highly
| proprietary[1] by the manufacturer, NXP. So I'll give this one
| a miss, and choose a FPGA based SDR instead. Some of the FPGAs
| even have a completely open-source toolchain, that has been
| developed by reverse engineering the bitstream format.
|
| 1. https://news.ycombinator.com/item?id=35357451
| gregsadetsky wrote:
| I'd love to decode some radio signals - just to go through the
| "motions" and try my hand at it.
|
| Is something like an AM radio signal decoding relatively easy to
| understand? What about FM? And NTSC?
|
| Is the python code clear-ish? Complicated? Full of math I'm not
| appreciating?
|
| Thanks!
|
| Ok... it's not exactly trivial:
| https://pysdr.org/content/rds.html#fm-demodulation
| mikewarot wrote:
| Try out gnu radio, you build flow graphs in a GUI and it
| executes them in real time.
|
| You really should play with audio samples from your system to
| get a feel for things, before diving into the math. You can
| also use it with a $30 rtlsdr dongle.
| sam1r wrote:
| >> https://pysdr.org/content/rds.html#fm-demodulation
|
| Wow! Thanks for posting this.
|
| It's not trivial, but very meticulously written.
|
| It would definitely classify as a "learn python the hard way"
| challenge for a math-y learner.
| actionfromafar wrote:
| For NTSC, also check out https://github.com/oyvindln/vhs-decode
| ale42 wrote:
| There's for example SDR++ (https://www.sdrpp.org/), which has
| lots of plugins to decode specific types of signals, or
| SDRangel (https://www.sdrangel.org/), which has quite some
| digital signal decoders built-in.
| pid-1 wrote:
| AM in particular is quite intuitive as you can study the
| modulation visually. IMO it's the "everyone could have invented
| that" modulation technique.
|
| FM is built on a simple idea, but it has more involved maths.
|
| Analog television signals are way more complex IIRC.
|
| Re: the lib you linked - libs used to deal with radio signals
| is made by people who have studied signal processing and comm
| systems formally so you will see lots of jargon and advanced
| maths like Fourier Analysis. However, you most likely can build
| something shittier yet working by yourself by understanding the
| fundamentals of how those signals are encoded, modulated and
| transmitted.
| goodboyjojo wrote:
| this is pretty neat. i remember some old guy on youtube showing
| cool things you could do with a cheap sdr dongle. and i remember
| some guy using gnu radio to hack into a car
| nullpage wrote:
| University of Twente in the Netherlands has a great websdr[1]
| running some custom hardware that can tune into pretty much the
| entire shortwave spectrum. I've spent countless hours tuning in
| to various European radio stations and broadcasts (you can even
| pick up the odd number station if you are on the right frequency
| and get lucky with timing).
|
| [1] http://etgd1.ewi.utwente.nl:8901/
| mpalfrey wrote:
| Have used this for number stations in the past. It's great -
| amazing what you can still find on shortwave.
| leesalminen wrote:
| This link is pretty famous in some "conspiracy theorist"
| circles, specifically those interested in "Skyking".
|
| Skyking is a military radio transmission protocol, believed to
| be command-and-control in nature. Some believe there to be a
| correlation between the length of the encoded message/how many
| times the operator says "Skyking" and the DEFCON level/how
| close the US is to blowing shit up.
| totetsu wrote:
| Randomly clicked on to a greek located site, and wondered what
| they were talking about so I sent a bit of the audio to openai
| whisper api just to find it was mostly radio etiquette and
| souvlaki recipes.
| totetsu wrote:
| > 12 and a half, one. So, I eat all my food. I eat these
| wonderful souvlaki. There's a table next to it. I sit down. So,
| once again, once again. The best souvlaki in Greece. What can I
| tell you? That's it. Every Saturday. And outside Athens. I'm
| not in Athens. Somewhere outside. So, we'll talk about it. So,
| Dimitris. So... Yes, yes. So, yes. Ok. I'll give the microphone
| to Papa My Golf. Ok. And he'll give 20 more. This time. So,
| I'll let Victor speak. I'm listening to you, Papa My Golf. Next
| time you should have more signals, Papa My Golf. We're probably
| talking less today. So, I'm listening to you. Ready. Good,
| good. There's a gap. Very good. The company doesn't help to do
| many things on its own. Whatever it does now. I think we should
| go to the next recipe. Thank you, Dimitris. I have a break.
| I'll give the microphone to him. Good morning. Papa My Golf
| here. Good morning. Papa My Golf here. Good morning. I think
| I'll give the microphone to him. I'll give it to him. Next
| time. Ok.
|
| > ![[websdr_recording_2023-10-27T05 51 46Z_7197.0kHz.wav]] I
| would like to wish you a very good morning, thank you very much
| for your years, and you too, if you have a celebration or you
| are celebrating, to enjoy them, to be well. Well, I have
| listened to Danasis, I have listened to Christos, I have
| listened to my friend Petros, I have listened to my friend
| Giorgos, all the company here. Well, I don't know, now I will
| listen to you here, if there are other guys, my good morning.
| But I won't take it, because I have to go. Just for a good
| morning, I stepped here at 797 and I know bread, and I will go
| to my friend Danasis, my friend here. It's me, your friend,
| come. Come, come, good morning, good morning Dimitris, good
| morning. What's up, what are we doing? I'm glad to hear you, my
| happy years, of course, I sent you my happy years yesterday,
| and I saw that you received it, so since yesterday it has been
| a while, but even today, it doesn't hurt, and the more wishes
| we give, the greater is the possibility that these wishes will
| come true. Well, I see. Don't tell me, let's talk for a while,
| Dimitris, before we move on to the next one. In any case, are
| you ready?
| adamjgs wrote:
| Most likely Papa _Mike_ Golf, rather than _My_ Golf, _Mike_
| being the NATO phonetic alphabet representation of _M_. It 's
| a reference to the last three characters of the operator's
| callsign.
| totetsu wrote:
| It sounds like Papa My Golf to me. I suspect 'pa:p@ maIk
| galf/ is reduced to 'pa:p@ maI galf/ because of the
| closeness of the K and G.
| lormayna wrote:
| Is there any good open source software for WebSDR? I am living in
| a very noisy area from RF standpoint, but my parents are living
| in a better position. So I was thinking to install a SDR and a
| Raspberry and use them as remote SDR
| squarefoot wrote:
| If you don't need the web interface and your usual desktop SDR
| software supports rtl-sdr tcp mode, you can easily set up a
| small board that calls rtl-sdr with the appropriate parameters
| so that it will wait for a remote connection from the above
| software, not unlike what happens with WebSDR, but you would be
| using your usual desktop SDR application which would be native
| and much more snappy than a web browser. Here's an example
| using gqrx.
|
| https://www.youtube.com/watch?v=74jDcHuDCmE
|
| https://gqrx.dk/
| lormayna wrote:
| Ah yes, good suggestion. I forget about it. I have a mini
| whip antenna that I can place on the roof.
| kareiva wrote:
| OpenWebRX is a good thing to start with, especially the fork at
| https://github.com/luarvique/openwebrx/
| perlguy9 wrote:
| WebSDR's are indeed awesome. Get your ham license and you can
| transmit too and not just listen!
| nolroz wrote:
| Why are there none in Canada? Or Australia? Are there parts of
| the world where Internet connected SDR is illegal or something?
| CrankyCanuck wrote:
| There are some (SDRs on the internet) Have look here.
| https://rx-tx.info/map-sdr-points
|
| http://ve3hoa.ddns.net:8073/
| luke-stanley wrote:
| Oh cool. I suppose since they have locations too, it should be
| possible to profile aggregated mains power fingerprints from
| these for video time and location fingerprints. Though that said,
| there are probably a few ways to collect that info. If you know
| the frequencies to profile you could probably store the mains hum
| for all of them and have a good go at geo-locating video and
| audio content for many places.
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(page generated 2023-10-27 23:02 UTC)