I have an NASA Inspire VLF-3 radio receiver kit that I'm going to put together. It amplifies VLF electromagnetic signals that are already in the audio frequency range and makes them audible. One of the interesting things that it may make audible are VLF whistlers, signals that are triggered by lightning strikes and produced by the response of charged particles in the ionosphere orbiting around lines of the Earth's magnetic field.
If I wanted to identify some times that were optimal or at least more likely to hear whistlers from my location, I'm thinking that I should check for times of high lightning activity, but should the lightning be nearby (I live in Asia near 25 N latitude), or should it be much farther north or south but at roughly the same magnetic longitude, so that the particles producing whistlers that I hear are more overhead and in a better vacuum?
I've asked separately: Are there websites where I can get “lightning frequency maps” in near-real time (worldwide)?
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