I is (should bee?) well known, than long distance lightning signals are following the ionosphere waveguide, and the dominent frequency in this waveguide is 10-11kHz.
What you see is exactly this phenomenon :-)
For the same reason, the receivers made for just very long distance lightning, are often tuned to that frequency.
Tuning provides shifts in the signal path (delay), and gives inaccuracy in the position fixing.
This delay we do not want - and that's why our receivers are a little more complicated than you would otherwise see.
What wave guide does is a physical phenomenon which we can not do anything about.
Well - because of this phenomenon, we can "see" far but not place determine as accurately as nearby lightning.
https://en.wikipedia.org/wiki/Earth%E2%8..._waveguide
/Richo
P.S. By the way - the signal you are viewing is often called "a Mexican hat"
What you see is exactly this phenomenon :-)
For the same reason, the receivers made for just very long distance lightning, are often tuned to that frequency.
Tuning provides shifts in the signal path (delay), and gives inaccuracy in the position fixing.
This delay we do not want - and that's why our receivers are a little more complicated than you would otherwise see.
What wave guide does is a physical phenomenon which we can not do anything about.
Well - because of this phenomenon, we can "see" far but not place determine as accurately as nearby lightning.
https://en.wikipedia.org/wiki/Earth%E2%8..._waveguide
/Richo
P.S. By the way - the signal you are viewing is often called "a Mexican hat"