Build A Cheap Airplane ADS-B Radio Receiving Tracking Station

Do you have commercial or general aviation flying over your home or near your home? Would you like to know more about these airplanes: identity, heading, speed, altitude and maybe GPS data along with even more information? Well then [Rich Osgood] has just the project for you and it’s not that expensive to set up. [Rick] demonstrates using a cheap USB dongle European TV tuner style SDR (software defined radio) tuner that you can get for under $30 to listen in on the Automatic Dependent Surveillance-Broadcas (ADS-B) (dead link, try the Internet Archive version) 1090 MHz mode “S” or 978 MHz mode “UAT” signals being regularly transmitted from these aircraft.





Wikipedia has more details on ADS-B and the sight has an excellent posting on “RTL-SDR Tutorial: Cheap ADS-B Aircraft RADAR” which includes how to build your own antenna for the 1090 MHz frequency

30 thoughts on “Build A Cheap Airplane ADS-B Radio Receiving Tracking Station

  1. regarding the legal frequencies.

    1. how would the government even know if you are monitoring those frequencies?

    it isnt like the receiver could transmit on them or leak onto them.

    2. remember the other fcc rule on many electronics?

    may not cause harmful interference

    must accept interference that causes undesired operation

    if you are using a cheap rc car and the motors suddenly act as speakers sue to it being able to receive a phone call.

    now the car is acting in an undesired mode.

    the way i see it the fcc set up a catch 22. in the rules.

    if you can exploit that and listen to the phone call via the toy’s motors and circuitry acting as a receiver then you should NOT be in violation since it is an undesired operation.

    ok here is another example

    lets say you are using a cheap toy walkie talkie that uses a slide switch similar to those used by older tape recorders (witch are known to get noisy) and the switch in the walkie talkie acts like the pencil and razor blade in the foxhole radio due to it’s noisy contacts and your walkie talkie act like an illegal receiver

    are you in violation due to a malfunctioning walkie talkie?

    1. Yes, it is illegal to monitor other people’s phone calls, no matter what device you use to do it. If you find yourself accidentally listening to a phone call then you should stop doing it.

    2. No, in none of the hypothetical cases you mentioned, would you be at fault, or prosecuted. In all actuality, no one would really care. The FCC isn’t in the business of chasing down children with broken toys. They’re focused, as you might expect, on individuals who are actively trying cause trouble.

      However, if the walkie talkie acted as an illegal receiver, and the company manufacturing the toy knew this could happen, and continued to manufacture them, the FCC might have a few words to say to that company. But still. The FCC would be chasing the creator, not the consumer who’s toy broke.

      This is why the creators of that RC toy, or the walkie talkie, would work very hard to make sure that their device didn’t violate potentially FCC rules.

      Also, towards your first point, about “how would they know”. They might know if:
      – You were the sort of person who would blog (write a research paper, a news report, a youtube video, etc) about doing it
      – You were doing it out in the open (like at a park, or at an Amature Radio gathering)
      – You were using information you gained from that in an obvious way (like posting information from telephone calls on a website)

      But they wouldn’t magically just “know”.

      1. Actually, and I don’t know about the dongle’s receiver design, but the resonant frequency of several common tuner circuit types can be detected by scanning with a narrow transmitter signal (Peter Wright helped develop this for MI5 a long time ago to locate possible spies in the UK who were monitoring Soviet transmitters). So they could conceivably “magically” know to what frequency you’re tuned, whether you’re listening or not.

        1. I should have added that the tuned frequency detector involves something akin to wardriving, since the return signal from the receiver will be weak and therefore the detector has to be in the vicinity. Besides, if it wasn’t, one couldn’t tell where the tuner was located.

    3. Interesting moral standpoint, ejonesss. If I understand what you are saying correctly, you either believe that it is only illegal if you get caught, or that a possible conflict between two different laws nullify each other.

      Just to be clear, neither of these cases are true.

      1. Not *any* RTL2832 receiver will work, although many of them will. As well as the RTL2832 chip, the receiver must also have a tuner chip capable of tuning to the desired frequency.

    1. it was an example so there is no known model that does that however some very cheap 1 piece phones from the 80s that was $1 with 5 proof of purchase tags from any chex packages and you got a one piece phone that was self contained and was the size of today’s cell phones did have an interesting flaw in the ringer circuitry.

      the phones used a piezo element for the ringer and it was sensitive enough that if another phone in the house was picked up you could hear the voltage change in the line as a click from the ringer piezo element. (more like a chirp)

      if another phone dialed in rotary dial mode you could hear the phone number being dialed by counting the chirp-clicks.

      if you held the phone to your ear with the hook button pressed you could hear the conversation from the piezo element.

    1. yup. That’s a horrible, horrible antenna connection. Nevermind the fact that you should not be using PL-239 (UHF) connectors at that band, but the loop between the shield and conductor is practically an antenna. I’m not sure if these programs use the 1090 extended squitter or 978 UAT, but either way, you’re talking about 1 GHz, here. Have some respect. :)

      1. I’m admittedly a radio noob. I wanted to see if I could make it work, and it did. I knew the “adapter” I made was pretty terrible but it did accomplish my goal so I still consider it a win. I think the best solution would be to build an antenna designed for this frequency (1090Mhz) and also use appropriate cable and connectors for that frequency. I’ll likely do this in the future since I plan to make a more permanent setup for ADS-B reception. I was working in a limited time frame though so like I said, I used mostly what I had around. I appreciate the feedback.

          1. I use BNC with all of my SDR stuff. As for the stupid MCX connector, I don’t bother with it at all, I just solder on a low-loss coax pigtail with a BNC on the end of it and away I go.

          2. (derail: the connector on this poor guy’s dongle is, however, the “UHF” connector. not the actual crappy Army UHF connector (which he then made a cable to connect the UHF connector with the “UHF” connector – total LOL /derail))

            the MCX connector doesn’t bother me – it’s a bit tiny and fragile but it has decent number of duty cycles and supports surprising frequency ranges. when I order these dongles I am really hoping to get the MCX ones not the crappy coax “UHF” ones.

            and you can get a male MCX right-angle pigtail, to just about any other connector. for about USD4 on ebay. including shipping.

            my latest preference is right-angle male MCX to male FME. FME also has a very high number of duty cycles and support for excellent range of frequencies. plus you can find a female FME adaptor for just about anything.

            but you can get MCX to F, to N, to BNC, to UHF. male or female. same 4 bucks, just like in town.

      2. correct, PL259/SO239 are basically pre-WWII technology and only truly rated at 30Mhz. I see vendors selling cables “rated at 300Mhz+” and yeah that’s great maybe your wire is, but your connectors most definitely are not.

  2. (also also, I have been using a r820t dongle with adsbscope and both adsb sharp and rtl1090, with a 70cm/2m zepp/j-pole slimjim. and getting planes up to slightly over 100 nautical miles. rtl1090 seems to provide better data but that is likely anecdata honestly. the J antenna is hung indoors on the 3rd floor / attic. this less than 100NM from Boston MA USA, and we also have a semi-not-quite-defunct Air Force base here. (so there are plenty of Unknown Airframes showing up yay))

  3. I went ahead and hooked my RasPi/R820T to a spare 10m/28MHz whip on the roof through a bunch of random coax. Running “rtl_adsb | nc –l 47806 ” to pipe the data over to ADSBscope via wifi.

    Even with the admitedly sub-optimal antenna and connection, I’m able to catch around 3-5 aircraft at all times. The pattern of the antenna system (including cable) at 1.090GHz is probably near-vertical, as most of the aircraft are directly overhead when I “hear” them. Fortunatly, I’ve got a federal airway running overhead, as well as the N/S runways of KDEN 35 miles to the south.

    My next steps are to (1) build a proper antenna, and (2) relocate the RasPi to the roof next to the antenna (shorter cable run). Overall, I’m pleased with the 10 minutes of work I put into this, and my kids get a kick out of watching ADSBscope as well.

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