Sunday, April 18, 2021

ADS-B Project

 One of the things I've been kicking around doing is setting up another small PC to run a couple of programs on so I can "watch" what air traffic is around us. The easiest way to do this is to monitor the ADS-B transmissions from the aircraft using a receiver and a PC to decode the transmissions, and then display them on a map.

For the receiver I'm using one of the ubiquitous "RTL Dongle" receivers and a vertical whip antenna, unceremoniously hung on the wall using the pull cord for the blinds.

This particular receiver has been optimized to receive the 1090MHz transmissions, as it has a bandpass filter and preamplifier tuned for 1090MHz.

Yeah, it's a kluge right now, with an inappropriate antenna, and a mess of adapters, but it's working better than I thought it would. Plans are in the works to build a proper antenna for it, but for now it's grabbing and decoding signals like crazy.

The main program is one called "dump1090", and it spits out all the data to a terminal window.


dump1090 also includes a lightweight webserver, so as soon as I can sort out some port assignment issues, I should be able to have this on the Web. Then I'll set up one of the small "bookshelf" PC's I have to run the programs, and make the data available to others.

After I get this working, I'd like to also build something to receive the ACARS transmissions. And then build a 137MHz Lindenblad antenna to receiver the APT satellites again. I tossed the "Eggbeater" antenna I was using for that back in Long Beach, and I'm still kicking myself.....



 

8 comments:

  1. No decent comment, I haven't a clue what you are doing.

    ReplyDelete
  2. Eventually, I'll have it all on a webpage, very similar to what "FlightAware" does. FlightAware is an app for your phone that lets you track flight by name/number, and displays it on a map so if you're waiting at the airport, you know the exact status of the flight you're waiting for.

    But this will all be "local", no phone needed!

    ReplyDelete
  3. In high school (circa the last dinosaur), I had every intention of learning more than the simple printed circuits I built. Life, time and tide wait for no man, as they say.

    ReplyDelete
    Replies
    1. I've been doing this stuff more or less continuously since about 1962. Got my Novice Ham license in 1964, and it led to a nice career in Electronics.

      Delete
  4. Drjim, for your 137 MHz receive antenna try L.B. Cebik's crossed Moxon's. They are physically easier to build than a Lindenblad array. I finally got mine to work as far as my nanoVNA shows for both 2M and 70cm. I have a URL that has the dimensions for 137 MHz one.

    ReplyDelete
    Replies
    1. I'll look into to those. I've got Moxon's book, and a lot of Cebik's things I printed out over the years.

      Delete
  5. For ADS-B, civil aircraft use 1/4 wave monopoles. They're usually dual use with the TCAS and Transponder antennas. They have the advantage of being outside, but sure aren't expected to have gain.

    ReplyDelete
  6. That's why I need a "better" antenna than the "900MHz" scanner antenna I have on it now. Even a 1/4-wave vertical might be better. The reason I brought up the Lindenblad antenna was because I'm toying around with making a PC board version of it.

    Getting the phasing lines right will be the hard part, but I've done a lot of microstrip design and layout, so I have a few tricks I've learned.

    ReplyDelete

Keep it civil, please....

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