FunCube meteor detector

After reading the article in the June and July editions of Sky at Night magazine I've been inspired to build myself a meteor detector.

The basic principle behind detecting meteors is very simple; when they hit the atmosphere they momentarily create an ionised layer that reflects radio waves - all you need to do is pick up this reflection.  In fact, people have been doing this for donkey's years using radios and home-made antennas.  Obviously, it's beyond most normal people's means to be firing radio signals up into space however.  The solution is to listen for existing signals being reflected rather than creating your own.  Ideally it needs to be a strong reliable signal that is not going to be detectable normally unless it is being reflected back of the upper atmosphere.  For those of us in the UK there is a convenient radar near Dijon in France on 143.05MHz.

On the PC side of things it's quite simple; all you need is a copy of the free Spectrum Lab application and the appropriate configuration file.  Helpfully, the S@N magazine supplied one.  This simple (and at the same time very complicated) application listens to a sound source and displays the signal in various highly configurable formats.  It can also be set to look for specific events and log them - E.g. the spike caused by a meteor.

So, now all you have to do is get some sort of signal into the PC in the form of sound.  I did consider using one of my old scanner radios but it proved a problem isolating them from the interference produced by the laptop.  In the end I opted for the FunCube dongle as used in the S@N article.  This is a very easy to use yet powerful software defined radio (SDR) designed for receiving data from the FunCube satellites but equally useful for receiving any radio signal on the PC.

At this stage I haven't got as far a building a proper antenna for it.  In fact I tried it for the first time last night using a short length of copper wire strung from our patio door across to the shed :)  However, it worked amazingly well considering.  I picked up all sorts of SW signals whilst testing it during the day.  I wasn't seriously expecting it to pick up meteors though without a better antenna.

Last night I left it set up and running whilst I was out observing.  As luck would have it I saw a bright meteor streak across the sky so I dashed back in to the house to look at the laptop screen.  There it was!  Only a tiny blip but it had been recorded at 22:58:15.

All I need to do now it work on a decent antenna.

For an idea of what its supposed to look like see the S.P.A.M meteor network site.