How does the lightning tracker work?

[daviescr]

A fairly simple question, but I suspect the answer might be a little more complex.

Would love to hear from anyone who might know how the technology works...

Here's my thoughts - I know that a lightning bolt produces an electromagnetic pulse - the static you hear on the AM band - so I wonder if that principle could be used on a wide scale, with multiple 'sensors' across a region to triangulate the source on a 2 dimensional level?

I also wonder if only CG produces such signals? or all types of lightning??

Hope there is someone out there who can answer my geeky questions

[Jake Smethurst]

Hi Chris.

Whilst I am not able to help much with the more technological side of this question, the lightning tracker you see on Weatherzone only picks up CG strikes. I have often noted this over the years, and it is the same with my own lightning tracker. I am not sure why exactly, perhaps to do with the spread of the electromagnetic pulse, which could be greater in CG strikes rather than CC or CA ones. I am interested in this too, perhaps Ken might have some knowledge on this?

[Ken]

Here's my thoughts - I know that a lightning bolt produces an electromagnetic pulse - the static you hear on the AM band - so I wonder if that principle could be used on a wide scale, with multiple 'sensors' across a region to triangulate the source on a 2 dimensional level?

You pretty much hit the nail on the head. LPATS (Lightning Position And Tracking System) networks need at least 3 sensors to triangulate the electromagnetic interference caused by a lightning bolt. But instead of using direction-finding (which used to give big errors), each of those sensors measures the exact time of arrival of the interference (they have GPS receivers so they can compare it with the GPS satellite time signal) to triangulate the lightning.

Most of the larger civilian and military airfields in Australia also have local lightning sensors installed. They use multiple sensors to detect the approximate direction of lightning as well as range. Depending on the airport, this is then merged with data from multiple nearby radars and automatically generates thunderstorm alert graphics for airport workers and the Bureau (it shows lightning location, distinguish between cloud-ground and cloud-cloud flashes, how many have been detected and show a 30min forecast of their tracks and times of arrival within various distances from the airport). A past example is below: