Lightning Maps

[Harry Bloomfield, Esq.]

I heard the rumbles, saw the flashes in the distance and as I was at home, thought to take a look at the above site. Odd watching the flashes through the window and seeing them appear on the map just seconds later. I also couldn't fault the actual location of the strike on the map, I wonder just how they work out the location of the strike?

[Chris J Dixon]

Following a link on that website leads to:

""Blitzortung.org" is a lightning detection network for locating electromagnetic discharges in the atmosphere (lightning discharges) with VLF receivers based on the time of arrival (TOA) and time of group arrival (TOGA) method. "

"The network consists of more than 500 lightning receivers and some central processing servers. The sources of the signals we locate are in general lightning discharges. The abbreviation VLF (Very Low Frequency) refers to the frequency range of 3 to 30 kHz. The receiving stations approximately record one millisecond of each signal with a sampling rate of more than 500 kHz. With the help of GPS receivers, the arrival times of the signals are registered with microsecond precision and sent over the Internet to our central processing servers. Every data sentence contains the precise time of arrival of the received lightning discharge impulse ("sferic") and the exact geographic position of the receiver. With this information from several stations the exact positions of the discharges are computed. "

Chris

[Pancho]

I would guess it is now satellites. It's one of those problems that could traditionally be tackled in clever ways, but once you have real time images it is easy to write a program to just "see" them.

[Harry Bloomfield, Esq.]

Chris J Dixon submitted this idea :

I knew it had to work on multiple reports of TOA I was just surprised at how good the timing was. They must have a lot of participants, providing stations feeding data into the system.

[Pancho]

It seems I'm wrong. There are satellite based systems but there is still a time lag. So they used ground based arrays.

I guessed satellites because I saw strikes in the middle of the North Sea, but I guess the ground based arrays can pick these up and triangulate.

[Bob Eager]

Amazed we haven't heard from w_tom yet. Unless he got fed up with all the alerts from my sig.

[Parsnip]

If you hadn't snipped it out you would've quoted that they have "more than 500".

HTH.

[Chris J Dixon]

Indeed so. Amongst the options on the website you can get it to show the ground station locations and the triangulation lines to strikes.

Chris

[Harry Bloomfield, Esq.]

Chris J Dixon used his keyboard to write :

I failed to notice that option. I have come across it before, though never had the opportunity with local storms, to check the accuracy.

[Brian Gaff (Sofa)]

Interesting story in this weeks New Scientist about the number of trees being killed by lightening is increasing and that some trees look alive afterwards, but do not come back the next year due to the damage internally. Brian

[nothanks]

Thanks for the link; fascinating to watch storms move about. I'm surprised at the distances that the triangulation system can pick-up a strike.

[Dave Liquorice]

VLF signals bounce a long way, you can get global coverage from a single transmitter and they penetrate water quite well. One or both of my two VLF transmitter neighbours are likely used to talk to our nuke subs where ever they are without them having to surface.