Lightning in XM weather

On Aug 15, 8:16 pm, "Danny Deger" wrote:
The engineer in me is dying to know how the sensors knows the difference
between cloud to ground and cloud to cloud. Anybody know.

Cloud to ground lightning creates a unique RF signature. By
recording these radio waves and by using time from GPS satellites to
corrdinate those receptions, then the NLDN could pinpoint those ground
strikes. When too many ground strikes occur, the network tends to
become overloaded; does not detect all strikes.

Then the NY Times made some inquires in response to a lightning
strike in the area of the former WTC that killed one person. Direct
lightning strikes known to have hit both the WTC and Empire State
Building (on average 25 and 40 times annually) were not detected;
apparently did not create that RF signature. No followup information
is available as best I can tell.

"w_tom" wrote

Cloud to ground lightning creates a unique RF signature. By
recording these radio waves and by using time from GPS satellites to
corrdinate those receptions, then the NLDN could pinpoint those ground
strikes. When too many ground strikes occur, the network tends to
become overloaded; does not detect all strikes.

In a gross simplification, cloud to ground flashes produce disturbances in
the LF and VLF EM bands. They are received over very long distances, so
they are easier to get a map of over a complete region, even with a sparse
location of sensors. Probably why it is desirable.

Cloud to cloud flashes are mainly in the VHF range, and therefore are line
of sight.

For a very complete explanation, see
https://www.thelightningpeople.com/htm/about/events/ildc/ildc2000/docs/03_CUMMINS.pdf
--
Jim in NC

On Aug 17, 2:35 am, "Morgans" wrote:
In a gross simplification, cloud to ground flashes produce disturbances in
the LF and VLF EM bands. They are received over very long distances, so
they are easier to get a map of over a complete region, even with a sparse
location of sensors. Probably why it is desirable.

Cloud to cloud flashes are mainly in the VHF range, and therefore are line
of sight.

Now explain why the system saw no strikes when 25 and 40 direct
lightning strikes hit the Empire State Building and WTC annually. I
have long been waiting for that answer. Do strikes to tall buildings
not create LF and VLF EM radiation?

"Jonathan Goodish" wrote in message
...
Most weather providers obtain lightning data from the National Lightning
Detection Network, which is operated by Vaisala. The network displays
cloud to ground strikes.

Thanks! I just learned something. You can get a free lightning map he
https://thunderstorm.vaisala.com/tux...r/explorer.jsp
It is for the entire USA, and only updated every 20 minutes, so you can hardly
use it to pick your way through the cells, but it could sure help you decide if
it is healthy to go flying.