Up in the dim warm loft of my house is a Raspberry Pi connected to an aerial. I’ve written about this a lot before, the thing tracks specific aircraft signals and then send those data off to a website for them to use to send to the world. I spent a little time yesterday adding the Virtual Radar Server software to the Pi so now I can see what my Pi sees in a useful format. I also have enabled this to be seen anywhere around the world using the brilliantness of the internet and such technologies. This picture shows you the UI and a long range view:
ADSB Receiver Range
I think the aerial was picking up about 90 aircraft when I grabbed this screenshot. I still think that’s pretty impressive. Here’s a more local view:
ADSB – Local Details
I know I have some issues with range detection aligned with how my terraces rooves are arranged along with a bit of a block to the north of the North Downs, but still, I think it’s impressive.
It has been years since I wrote a communication about my aircraft tracker that’s installed in the loft. I have an aerial connected to a by-pass filter and amplifier connected to a Raspberry Pi which decodes the semi-automatic radio signals sent by aircraft and plots them into a map for me. I also upload the data to a website which anyone can access for a small annual fee. I used to regularly put a “splat” on this site which shows a map of aircraft coverage over a period of time. I have stopped using that part of the software – although I might reinstall it, will have to think about that. Without the virtual radar server all I can do is get a map output of which aircraft are currently being tracked. This was the map I got a few moments ago:
Not A Splat
It still impresses me how far the aerial can “see”. It would be cool if I could raise the height a little more and have the aerial outside but that would require professional installation so maybe sometime in the future.
A few summers ago my project was to build an ADS-B receiver and use the data collected to upload to an aircraft tracking website. If you want to see what I see then go to:
I don’t remember the details about how I found this but the project was good fun and I got the Raspberry Pi in the loft with a decent aerial, filter and pre-amp, and it was all working fine. I was using a lovely piece of software called Virtual Radar Server and was able to use this as a web server and people could see the aircraft on web pages served by the Pi.
360 Radar is good because it using multi-lateration to detect the positions on military aircraft. This is pretty handy for spotters like me and it also works well when I take cadets to RAF Wittering for some Air Experience Flying, I can see where my cadets are in the air.
Over the last few months I’d been receiving outage warnings from the 360 guys. It would appear that my Pi had stopped sending them data and while I live in a flight-busy area of the country and there’s plenty of contributors here every little helps. I had the occasional outage and this seemed to be when the router reset and the Pi wouldn’t re-find the existing wi-fi network. I just had to power cycle the Pi and everything worked fine. The outages seemed to be occurring more over the last while with the Pi stopping feeding every few days.
At first I thought it was a wi-fi issue so I bought some new ethernet-over-power adapters and linked the system into the route via a wired connection. This also meant I could ssh in to the Pi even if wifi was the original problem. I tried to work out how to turn the wifi connection off entirely but just ended up changing the SSID the Pi looked for as a simle way of ensuring the wired connection took preference.
After a week of testing I was still getting outages and my initial thought was that the VRS software was making the Pi work too much. I’m not sure why I thought that but I looked up ways to remove VRS. This was not the easiest as I had installed it years ago and couldn’t remember how it ran within the OS. I eventually managed to remove the Mono service and this stopped VRS running.
It was at this point I worked out how to use the log file of the MLAT client and I could see that all the software seemed to be working fine it was the Dump1090 program that didn’t seem to be sending data internally. I figured that Dump1090 had somehow stopped receiving the signal from the aerial. It all worked fine after a reboot and so I decided to replace the USB dongle that was decoding the ADS-B signals. I ordered a FlightAware USB stick and at the same time decided I would rebuild the Pi OS from scratch to have a “clean” build.
Once the new USB stick arrived I turned off all the systems and followed the excellent instructions from the 360 Radar guys to rebuild the OS of the Pi and just run a lite version of what I had been doing before. This took a while as I mistakenly thought the Pi wasn’t uploading to 360 because I was looking at the wrong server details. After an email to the support chaps it turned out I was contributing and a couple of hours of troubleshooting by me hadn’t been worth it!
So, the Pi sits in the loft, chugging away supplying data to 360 Radar, in return for which I get free access to their excellent tracking site. I’m running dump1090-mutability along with the MLAT-Client from 360. I’d really like to be able to allow you all to see the output of this but Mutability doesn’t have an external feed and I am not opening up my 80 port for the world.
What’s the point in having an ADS-B receiver if you aren’t going to use it when you are out of your house? So, I managed to set up some wizardry on parts of my home network and now I can see the display from outside the confines of my wireless network. I’ve done some port forwarding and other lovely stuff which is easy enough if you are adept at googling, which I am.
Family thinks I’m a god because I can use regedit to fix a computer. But I’m really quite good at JFGI.
So, I now have a Virtual Radar Service for the area around my house that I can log in to from anywhere in the world. I did have to set up a Dynamic Domain Name Service for my modem as I am not lucky enough to have a fixed IP from my broadband supplier. My router even informs the DDNS service what its new IP is whenever it restarts and because this just seems to work it makes me happy.
I did have some minor issues with the radar service as it uses Google Maps to provide a nice background and because I was using this outside of my home network I needed an API key to make this work. That was reasonably easy to set up but then it turns out that Google recommend you secure the key to a particular site so that other people can’t use your key and steal your Maps data, which would then mean Google would charge me.
It took a little while to get the formatting of this securing correct but I think I finally managed it. I guess I’ll soon find out if Google send me a massive Google Maps API bill soon!
So, I can log in to my radar server from anywhere and view it on a desktop or mobile device. That way I can see what my home system sees. It doesn’t catch all planes because some won’t be broadcasting position, see the MLAT communication. Below is a picture of a browser with my radar server running.
Virtual Radar Server
If you want access I can allow it to you. Just let me know and I’ll arrange a login and password and also give you the URL.
Further to my previous communication about my virtual radar set I now have been investigating what can be done. I’m waiting for a Raspberry Pi and then I will be able to move the aerial unit higher in the house.
In the mean time, here is a “splat” of what I can “see” using the original aerial and no RPi.
Radar Splat
Here’s a version zoomed in a little. I’m thinking of taking the unit to the Lake District soon!
Radar Splat
The different colours represent aircraft at different altitudes. The higher the plane the further away it can be seen.
