Pre-Amp Filter

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
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.

A side by side comparison.

Virtual Radar

A while back I wrote about setting up an ADS-B detector in the loft. There are six communications I think.

And this one makes seven.

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.

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
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.