Blitzortung Time Of Arrival project

I have recently joined the Blitzortung network, mine is the first TOA station in the UK. Check out the Blitzortung.org page for details. I stumbled across this site a few years ago and it has always interested me so I thought it was time to make my contribution.

Weather, as we all know, is a very British obsession and I am probably more obsessed than most. Lightning scared the **** out of me when I was a kid which probably explains my fascination with it now. There are other posts to follow concerning lightning detection.

The setup here consists of a hacked Compaq T1010 thin client running DamnSmallLinux (see winterm.gaast.net for details, I will add a post here later) and the PCBs, Ferrite rod antennas and GPS available by special request from Blitzortung.org.

Generally I am not one for building electronic kits, I prefer to do things the hard way and mess with chemicals to make my own PCBs, but this build was a complete breeze, the PCBs are made to a very high standard. Everything worked right away (a first for me).

The Ferrite rod antennas  proved to be a little more fragile than I expected, I managed to break one of them rendering it completely useless. This has meant a delay in becoming fully operational (waiting on a replacement at the moment).

Another problem was caused by the source code for the Linux Tracker. All credit to the author Egon Wanke, this code works perfectly with Linux kernels newer than 2.6.0 but for my Linux it caused unending Zombie processes. I should state that anything higher level than assembler language is voodoo to me so I had a bit of a time sorting the problem. Linux comes in many flavours and things change with its development. C++ is used for the source code and it would build with no errors or warnings. After much searching google I found the answer, SA_NOCLDWAIT is only available after Linux 2.6 so by using signal(SIGCHLD, SIG_IGN); before fork() the Zombies disappeared for good. Phew!

I will post a few photos when I find the motivation. In the interim, why not check out the Blitzortung site and maybe join up? It's not difficult and we need more participants in the UK.

Here is the "business end" of the set-up, yes that is a bit of Wickes own brand down pipe!
The large box is made from PVC sheet and is glued together with normal PVC plumbing cement.

Antenna housing with the GPS receiver in the lower right of the picture