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 logged into 360 Radar to see what’s flying around [not that I hear anything]. I was just curious but I was shocked at what I found! I wasn’t shocked. I was pleasantly surprised but not shocked. I was trying to write in a click-bait format then, but I should’ve made the title completely click bait. Now I think about it, a lot of the titles of communications on this site are a bit click baity. I don’t really say what the communication is about I just write an obscure title. I can assure that writing them that way makes things much harder to look up in the future.
Nothing Over Kent
Nothing up there really. The Kent skies seem rather empty. Oh well, the flights will be heading over soon.
This is communication number 1955 and so here are some things that happened in that year of the common era:
60,000 non-whites are forcibly evicted from their homes in South Africa.
83 people are killed in a crash at Le Mans.
Ruth Ellis is the last woman to be executed [murdered by the state] in the UK.
This morning I was watching my MagicMirror and up popped a RRR callsign on the aircraft near me section. Well, it wasn’t near me but it was close because there aren’t really any aircraft out there at the moment as the world has gone to shit. I checked with 360 Radar and it looked as though this RAF Cargo flight would pass quite close. So I got the camera and headed out to the garden to see what I could get.
Contrails
Here’s a cropped view, which looks a little better.
RAF C17 passing over Kent
Also, because the weather’s been nice here’s a photo of one of the plants in the garden. It was taken by son #1 and is a pretty good shot.
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.
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.
A couple of random things in this communication [aren’t they always? I hear you cry].
firstly, a while ago there was some lovely helicopter noise over my house late at night. I looked it up on my flight tracker and discovered the Army Air Corps had passed exactly over my house.
The Army Air Corps just flew over my house!
Well, not all of it, just two people. pic.twitter.com/T2itJDcKkh
Then, last night, while looking for the rain storms that were meant to be hitting the UK I noticed a Royal Moroccan Air Force Gulstream circling above the Essex – Hertfordshire border.
RMAF Heading to Stansted
I followed this for a while wondering where it was heading, eventually it turned towards Stansted airport and I didn’t follow it all the way.
RMAF Heading to Stansted
My suspicion is that this flight had some dignitary on board heading for medical treatment in London. The Saudis do this quite often and you can see their planes land at Stansted. The rail links are pretty quick as are road ways and even helicopter flights. The security is top-notch there too as it is where Air Force One lands with POTUS.
Gulfstream and Thunderstorms
The above picture shows the thunderstorms heading over the UK along with the RMAF Gulfstream track.
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.
There’s nothing on at the cinema I want to see tonight so how about a picture of the aircraft I am currently tracking?
I don’t think it’s too bad. I’ve been working on port forwarding and things to try and see stuff outside my home network and it’s getting there.
This isn’t all the aircraft my receiver is getting signals from but it shows the aircraft with known positions, the ones that broadcast their GPS location.
A short while ago my proper aerial turned up for the ADS-B system I have running in the loft. See this communication and this one also. This new aerial means I should have a better receiver based in the loft. It is currently picking up 47 aircraft flying within range and the Virtual Radar Server gives the following as a webpage output:
There is a sidebar which connects to the web and gives me information about the selected aircraft and the others flying within range. This does not show all aircraft, only those with an ADS-B transponder. I also supply my data to a MLAT service for 360Radar.
The above photo shows the system in the loft. The white stick is a surround for the aerial. This connects to a dongle which connects to a Raspberry Pi3 and this, in turn, connects wirelessly to my home network.
I know you really want to know about the splat so here they are. Firstly one from before the new aerial.
Constriction
Here’s the latest, all altitudes are in one colour.
The range is a bit better with two very odd pips into central France. The following is a colour one for you mammals out there.
The next thing is to try installing a purpose made ADS-B USB stick. After that I think I will stop. It appears to be one of those “who can get the best splat” things online and I’m not interested in taking part.
I have noticed that I have decreased range in two directions on the ADS-B receiver.
There’s a waist!
Because the colours represent the ranges at different altitudes I’ve got a version with just one colour.
Constriction
This one shows a clear restriction in range in the NW and SE direction as marked by the red line. I do not know what is causing this but I have an observation to make. I live in a row of terraced houses and the direction of the road matches the constriction direction. While the aerial is in the loft there is extra “stuff” in the way in these directions because of the houses next to me.
Terrace
I’m pretty sure this matches up. There is definitely a correlation. Whether that means there’s causation I don’t know but it seems reasonable. I might write a communication about altitudes and the natural obstructions around me [I’m looking forward to the maths involved].
This is an update on the ADS-B device. I have written about this in the previous two communications, here and here. So, on Tuesday 2nd August the Raspberry Pi arrived. Since then I have been setting it all up so the receiver is no longer dependent on the PC being on.
The first thing was to install the correct OS on the Pi. The picture shows it in initial phase with monitor, ethernet, keyboard and mouse all connected. Once the OS was installed I had to tell it to not load the GUI and just run a command line. Then, I got it connected to the network and pretty much removed all the cables apart from power.
I can connect to the Pi using SSH and run script from the command line. Next phase was to load the USB stick drivers and software. This was reasonable. Next up was the ADS-B reading software, installing and getting it running seemed easy enough and then I had to adjust some code to make sure this service starts up from boot. Next software to load was the MLAT server program, this was easy enough although initially I couldn’t quite find the correct code to check it was running.
Then, the whole set up was tested in the dining room window.
Today has been the task of moving the unit to the loft. I didn’t have any power sockets up there so one had to be installed and that took the time! Once that was done the system just needed to be secured onto the main beam in the loft. The important thing is to keep the length of the cable from aerial to dongle as short as possible, this increases the signal going into the Pi. The loft set up has been tested and it is running fine.
I have access to the Pi either via the PC using a program called PuTTY or the iPhone using an SSH connection. I can shut down the Pi remotely and monitor the internal temperature of the device. It is running at a range of 50-60 Celsius. Using a Pi to run this software is a bit like taking a sledgehammer to a walnut. But, it is independent and runs remotely. I am happy this procedure was reasonably straight forward!
The next stage is to get a more specialist aerial and maybe a more specific USB Dongle. However, this is one of those things where the amount of money you spend can be unlimited. You know, I could just install a radar up in the loft. However, here is the current splat for the range of the aircraft from my ADS-B receiver.
Loft Splat
Now that I’ve been reading a bit more about this type of thing I can explain a little more. ADS-B is broadcast by many aircraft and they send this on 1090MHz. These are the signals I receive in the loft and can see on my Virtual Radar Server software. I also send these signals over the internet to a new “radar” website. The ADS-B signals contain bits of information about position and heading, these are sent to a server which can determine positions of other aircraft by using time differences between signals arriving, this is called MultiLateration or MLAT. My Pi is part of this network allowing Radar360 to “see” more aircraft than just ADS-B alone.
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.
