Lightning Sensors
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Joined: Apr 2000
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From: IOM
Lightning Sensors
Two of the aircraft types I have flown have had lightning sensors fitted. The relative bearing indication I understand to be similar to DF, but does anyone know how these devices measure the range of the discharge ?.
Joined: Apr 2002
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From: Nirvana South
Capt. H,
From the L-3 (ex-Goodrich, ex-Ryan) Stormscope website:
The Series I ranged storms using the amplitude of the 50 kHz component of the lightning strike. The WX-1000 series uses several aspects of the 50 kHz component (Rise time, fall time, pulse width, etc.) The WX-900, 950 & 500 look at the same aspects of 11 different frequencies to range the strike. In addition the WX-500 & 950 have a “CELL” mode and a “STRIKE” mode, the Strike mode displays the strike similar to the Series I (with radial spread) and the Cell mode uses a more accurate method of ranging the strike.
I was once told that the direction finder approximated a 10 MHz ADF.
The Honeywell system may use a different method as it only shows areas of strikes as symbols rather than the dot per strike of the Stormscope.
From the L-3 (ex-Goodrich, ex-Ryan) Stormscope website:
The Series I ranged storms using the amplitude of the 50 kHz component of the lightning strike. The WX-1000 series uses several aspects of the 50 kHz component (Rise time, fall time, pulse width, etc.) The WX-900, 950 & 500 look at the same aspects of 11 different frequencies to range the strike. In addition the WX-500 & 950 have a “CELL” mode and a “STRIKE” mode, the Strike mode displays the strike similar to the Series I (with radial spread) and the Cell mode uses a more accurate method of ranging the strike.
I was once told that the direction finder approximated a 10 MHz ADF.
The Honeywell system may use a different method as it only shows areas of strikes as symbols rather than the dot per strike of the Stormscope.
Joined: Dec 1998
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From: Escapee from Ultima Thule
They have an internal model of the signal stength & characteristics of a 'typical' lightning flash(es). The received signal is compared to the model & algorithms calculate the distance using the principle that signal strength reduces with distance.
