From Zero to Air Traffic Control for $25 or less

By | February 7, 2013

Little known fact: I got my private pilot license (VFR) about ten years ago. I’d always wanted to be a pilot, so when the opportunity presented itself I took it. Got 42 hours of instruction/flight time in 2 weeks for about $3,000.

I’ve flown twice since then, and my medical lapsed long ago. It’s a very expensive hobby, and I’ve had other priorities.

I’ve always been interested in flying. I had a plan to join the Army and fly Apaches, but unfortunately that wasn’t in the cards for me. As a teenager, I lived along a military training route so I got to see all kinds of rotorcraft flying about 1000′ overhead. There is nothing more terrifyingly awesome than 10 AH-64Ds and 5 OH-58s buzzing your house in formation.

For the last three years, I’ve lived within spitting distance of an Air National Guard installation. I get C130s doing touch and gos for hours. I get OH58s and UH60s just over the treeline. I also happen to be in “Long Final” for Nashville International Airport, so during congestion I get to see 5-7 passenger jets stacked up waiting to land. It’s pretty neat.

Last year, I saw an article on Hackaday that showed a guy using a cheap TV-tuner to decode aircraft transponder signals. HOW COOL IS THAT?

Unfortunately for me, like many really cool software projects this one was all Linux and C and Mac. I’m a geek, but not that kind of geek. Linux just HATES me. I bought two of the tuners anyway knowing that eventually the Linux guys would make it easy for us Windows folks to play along.

That day has come. Yesterday I got both of my tuners hooked up and receiving ADS-B signals. I’m using the stock antenna, and it’s poorly placed, so my results are not stellar but they ARE working:

Now, how did I get here? Well, first you need the correct tuner. If you want more technical details, google up “RTL SDR” and spend a few hours reading. If not, just get this tuner:

I have the slightly-less awesome version running the E4000 chip, but I’m ordering two of these shortly for another project that I’ll talk about at a later date.

You’re also going to need some software (download and uncompress to your desktop or some other folder):
The latest version of Zadig (and 7-zip to uncompress the download)
ADBS# (Project Page)
adsbscope (Project Page)

Got everything? Here we go!

1. Plug in the antenna to the tuner
2. Plug in the tuner to a USB port
3. Run Zadig and replace the driver, following the instructions here. Stop when you get to the section titled “Automated installer”
Note that the screenshots are for an older version of Zadig. Mine didn’t have “Bulk-In, Interface (Interface 0)” as an option. “RTL2832U” was what was presented to me. Also very important: You have to do this once, and only once, for every USB port you plug this in to.
4. Open “ADBSSharp.exe”, which is wherever you unzipped it after downloading. Keep the default settings and hit “Start”
ADSBSharp

5. Open up adsbSCOPE. It’s pretty far down in the folder structure where you unzipped it. I unzipped it to a folder called “ADS-B” on my desktop, so the executable is “Desktop\ADS-B\adsb_all\pc_software\adsbscope\26\adsbscope26_16384.exe”
ADSBScope_explorer

6. Go to other->Network->Network Setup. Change your settings to match these:

ADSBScope3

7. Hit the inexplicably greyed-out and confusingly-named “start RAW-data CLIENT” button:
Start

Now you’re reading data! But we aren’t quite done yet. You probably don’t want the map centered in Europe, and you probably want an actual map. To re-center, go to Navigation->goto Town or Airport and choose the closest large airport by it’s call letters.

Next, go to load Maps->Background Picture. That should load a rudimentary map with interstates, and major cities. Go to load Maps->Northamerica USA ex. alaska to load state lines.

That’s it!

atc

 

Now, the thing about these signals is that they’re very sensitive to interference. I can pick up only very strong signals inside my office, but at home I pick up a lot more. It’s still not everything, though, because I have trees, buildings, and hills in the way. Also, the stock antenna is not designed for this radio band, so it’s passable but not great. Ideally, you’d want a specially designed antenna mounted on a pole at the top of a hill. There are some other really cool things you can do, like mounting all this stuff remotely and having the data streamed to you or to an online service that will do the mapping for you.

There are other programs you can use to decode the data that comes from ADSB#. I’m going to be testing out a few of them to see what works best for me. I’m interested in an Android app that can decode the signals as well, but my searches so far have been unsuccessful. I have a feeling that a better antenna is really something I should look at, but I’m not quite ready for that yet.

Stay tuned!

10 thoughts on “From Zero to Air Traffic Control for $25 or less

  1. Nate

    Now the question is will you be able to track the drone that will be flying over the US soon? That would be useful data.

    Reply
  2. DarrellK

    I need to look into this more. Can I run this on my laptop sitting in the right seat while I fly around?

    Reply
    1. wizardpc Post author

      Don’t see why not. I’d definitely test it on the ground for instrument interference. The dongles are receivers only, but they’re unshielded.

      Reply
  3. MattCFII

    Very cool!

    But for the drone thing, I think a lot of them will be transponder less RC airplane model size especially at the local levels. Transponder use would be for those closer to manned aircraft sized, which would more be at the Federal, state, large city level.

    Follow up to Darrell’s question, does this only detect aircraft with ADS-B out or will it detect standard transponders? Right now it’s use as a traffic finder would be limited if it is only ADS-B. Also if a standard transponder is detectable you would have the same problems any other passive traffic system of needing to be in an area of radar contact to interrogate transponders.

    Reply
    1. wizardpc Post author

      I’m actually much less concerned with the smaller ones. If the govt is deploying one of the smaller ones, it’s for a specific incident like a hostage situation or something. The larger ones can fly longer and therefor can be deployed more often, and with less specific purpose.

      Now, these little dongles will only do ADS-B on 1090Mhz. The developer says that the dongles can’t handle the amount of data that the 978Mhz UAT transponders output. There is hardware to available to do it, but it’s like $700. My understanding is that the FAA is mandating that all aircraft in controlled airspace use the 1090Mhz beacons, with extended Mode-S data (Lat/Long, Speed, Heading, Alt) by 2020.

      I’m still in the very early stages learning about this stuff, and a CFII would know more than me 😀

      Reply
  4. MattCFII

    Yes, definitely. But FWIW, the smaller ones are the first to be allowed to use airspace, the larger ones still are limited in air space (not that agencies like Customs can get around that). Also with multiples of them, you can get to a fairly similar capability. Watch some of the videos that Professor Vijay Kumar has put out on his autonomous quadrotors and think of how many more things a swarm of these can do…

    On the other hand some of the camera systems on the Predator/Reaper/Global Hawk class of UAVs is getting pretty scary. There’s a good Nova on it that shows system I can’t remember the name of but basically gives you a whole city view instead of the up until now soda straw one and it can give multiple views zoomed in at one time, it will be/already is a game changer in drone usage.

    ADS-B out is mandated by 1/1/2020, so you still have 7 years until all aircraft have it to go into controlled airspace. You will still have plenty of aircraft that like now if flying at uncontrolled airport you don’t have to have it.

    But you would think UAV ADS-B implementation should be more stringent since they have more traffic avoidance issues.

    Don’t get me wrong though, I’m totally doing this for the sheer cool factor. Feel free email me if you have more aviation refresher questions, since you have decoded my username LOL (aviation guys even miss it sometimes).

    Reply
  5. Pingback: APCO-25 Scanner for $25 | Guns, Cars, and Tech

Leave a Reply

Your email address will not be published. Required fields are marked *