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.
Just browsing my favourite aircraft tracking website and decided you should know that air-to-air refuelling gets practised off the Norfolk coast. See this Voyager aircraft enjoying the baking weather in this country.
Refuelling
The green box is the area they are allowed to practise. The red planes are military planes, not all of them, but those transmitting ADS-B. I would expect that some Typhoons are over the sea taking on fuel from the Voyager.
I’ve written here quite a bit about ADS-B and stuff along with tracking aircraft and multi-lateration. Well, I was looking at the aircraft tracking website 360 Radar this evening and spotted an amusing thing.
Almost A Penis
The route shown on the picture is that taken by an RAF Voyager aircraft over the North Sea. The plane took off from RAF Brize Norton and headed out over the Scottish area of the North Sea. The green area is rain and the purple highlights are RAF airfields along with the blue highlights showing civilian airports. What particularly struck me about this picture was the almost-penis drawn as the second area of activity. I think they should have tried a little harder [but would probably get “moved” assignment].
Let’s put this thing into some perspective by adding recognised Danger Areas in red and refuelling training areas in green.
AAR Ranges
Now we can see that the Voyager has maneuvered beautifully through the danger areas and maintained some lovely flight paths in the AAR areas. The plane is currently at 16,000ft and moving at 330 kts. Pretty standard stuff.
It’s amazing to see that this is practiced and practiced to make sure that when it comes to doing this in a real theatre everyone knows exactly what they are doing and it all goes to plan.
In a previous communication about Tattershall I said that I had heard that the RAF Typhoon display pilot was going to practice his display. This sort of information is publicly available through NOTAMS, Notices To Airmen. There are websites that give this information in map form. Basically if a crane is erected or there are runway issues or events coming up that might affect flying then information about that thing is posted to NATS.
Typhoon NOTAM
This is the Typhoon NOTAM with information about where and when. That way, if you are planning to fly there you can avoid CGY.
Here’s what the pilot had to say about his display:
Well another great #phoonfriday for me to end the week. The fighter didn’t fancy it this morning despite the perfect weather but the family model was very keen this afternoon so that’s 1500ft complete! Roll on 1000ft next week….. 🤞🏼☀🚀 happy weekend all! 😎
He went up in a two seater so I wonder if he was being assessed. I remember being at Linton-On-Ouse when the Tucano display pilot was having his assessment to get his display ticket for the season, you could hear the engine pulling the plane in high-g turns just above the airfield. It was very impressive.
I wandered lonely as a cloud
That floats on high o’er vales and hills,
When all at once I saw a crowd,
A host, of golden daffodils;
Beside the lake, beneath the trees,
Fluttering and dancing in the breeze.
Lonely Cloud
It’s interesting, the level of science and technology we have and use daily without thought far far surpasses that of any previous generation and yet we take it all for granted and have little care for how that technology works.
I was tracking a VW Group jet into Biggen Hill Airport in south east London and noticed that the waiting pattern was out over the North Sea.
Waiting For Biggen
I decided that the views out there can’t be that great. I’m also curious as to whether there is a beacon somewhere in the middle there. I don’t really know a great deal about the navigation of planes. VFR is easy, but other than that I need to read up about it all. Maybe I need another visit to Pooley’s?
Here’s a closer look at the waiting room:
Nothing To See
This Embraer has left a beautiful track for us to see. This is the waiting area for London City and Biggen Hill.
I am currently working on the Raspberry Pi I have installed in the loft as a web server and aircraft spotter. It’s been a while since I mentioned it here. I thought I’d just chuck up some images.
Aircraft Tracked
This picture gives an idea of how many aircraft can be tracked at once. Be aware this was early on a Sunday morning.
Radar Splat
This splat shows how far away aircraft are detected. Please note I am not where the blue dot is, that would be quite weird. The smallest locus is up to 9,999 ft, the green is 10,000 to 19,999 ft, the purple is the 20,000s and the red is above FL300.
With reference to the previous communication I can update the main blockages on the ADS-B splat. I wrote about this before here.
Blocked Areas Labelled
The blocked area labelled 1 covers the North Downs. This natural boundary lurks to the NE of me and I can’t do a great deal about it.
The blockage labelled 2 is, I believe, down to the aerial being inside my loft and the terrace houses of my block extending in that direction. I wrote about that here. The only way to improve this range would be to get the aerial placed above the roof of my house, which is not a job I am going to undertake. I may, however, consider getting someone else to do it.
These communications contain many items concerning the virtual radar system that lives in my loft and you can see a selection here. A short while ago I decided to buy an pre-amp and filter for my system to improve the range and number of aircraft being received. So, this communication now requires a large number of pictures to give you an idea of what this means.
Pre Filter Range 1
In the above picture you can see that there are around 20 aircraft and the black area [the range of the receiver] doesn’t quite reach Norwich, Portsmouth, Bristol or Calais. There is the NW-SE block as described before.
Coloured Splat
This coloured splat gives pretty much the same information but uses colours for the ranges of aircraft at different altitudes.
I bought a filter which only allows signals close to the 1090MHz requirement through to the USB stick I bought. It also acts as a pre-amp so there is an overall 14 dB gain.
Pre-Amp and Filter held securely in place
Here is the whole Virtual Radar system living in the loft:
Pre-Amp Filter, USB, Raspberry Pi
Once this kit was turned on I looked at the DUMP1090 output from the Raspberry Pi and pretty much shat myself at the number of aricraft shown:
Initial DUMP1090 view
When this view is compared to the twenty or so aircraft that I had before you can see an immense improvement in the receivers ability.
Virtual Radar Server View
Virtual Radar Server is a program I use on the RPi for a more detailed view, there are quite a few customisations you can create also. It is the software that will create the splat over time, keeping track of the aircraft and their position.
Holy Splat!
The distances have increased as has the overall coverage. I now track around 100 aircraft at a time. For a small sum of money the overall increase in detail has been terrific. I can now reach over northern France, over Wales and a lot of the channel to the SW.
I am aware that in some places on the internet caturday is a thing. I do not care for this. Nor do I care for cute dog picture stuff. It’s quite boring, especially when associated with a meme [a word now misused]. There is a smaller, some might say darker, part of the internet where comparing the range of an ADS-B receiver is a thing. These are called “splats” and so here is my Splaturday picture.
There are other communications cover this sort of thing here and here.
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.
I’m interested in aircraft. I don’t know why it started but it’s pretty much always been there. I grew up near Stansted airport and I can remember seeing the Space Shuttle visit in the early 80s, I saw the 747 and Shuttle circle around from the primary school playing field. When I studied art at secondary school every picture of mine contained an aircraft much to my teacher’s annoyance.
Nowadays it’s easy to see aircraft on the web. I have the planefinder app installed on my phone and often tweet when I spot an A380. I only really tweet the A380 as it’s massive and extremely beautiful.
My aircraft thing also meant I travelled to Stansted to see Air Force One take off a few months ago.
28000
I wanted to find a way to see what military aircraft are doing in the skies and I found a website called 360Radar who have this information. The site isn’t open to public yet and I emailed to see if I could get a test account. They said yes.
I like the site. I like the filters and information that I can see. This site relies on people sharing their MLAT data with them and they will offer a free account if you share data. They have a great comprehensive guide to setting up a system that is currently here. I ordered a small aerial and it arrived today. Within about thirty minutes of getting to the computer I was running the data server and sending information to the network.
I have a USB aerial picking up 1090MHz signals from aircraft. I then have a small program running to collate that data and form it into useful data.
Screen Grab of ADS-B Signals
You can see that I am picking up an aircraft over Cherbourg which I think is quite impressive. All of my aircraft are south of my position because my aerial is placed in a south window. I will look into moving the aerial to a more central, higher position in the house so that I can pick up aircraft all over!
Here’s another screen grab of the output from my aerial.
Another ADS-B Map
How it works
Many aircraft broadcast position information on 1090 MHz. This information comes from the aircraft’s navigation system but does not require the pilot to be involved in the operation of the system. The position of the aircraft is determined by GPS. This output information is called Automatic Dependent Surveillance Broadcast. My little aerial picks this up and reads it. My computer then sends this information to a website which aggregates the information.
For aircraft that don’t output the ADS-B signal their position and direction can be known using multilateration [MLAT]. This involves two or more base stations and measuring the time difference between each station receiving a signal. It’s very clever!
