[Q] Strikefinder Theory of Operation

Group-

I'm curious how Strikefinder technology works. Yes, I know some of
the basics, but what's curious to me is the ability of this device to
estimate range and direction to/from a lightning strike.

What I know thus far is the following:

1. Lightning is nature's version of an impulse function (time
domain), and thus it has wide bandwidth (frequency domain).
2. Strikefinder technology originated, I think, because it was
observed that lightning strikes showed up as noise in ADF units.
3. Strikefinder technology operates, I think, as a specialized AM
receiver that attempts to interpret energy bursts as lightning
strikes.

O.K., now I'm getting on the fringe of my knowledge. Yes, I'm an
electrical engineer, so don't be afraid to dive deep into details. I
just hadn't considered theory of lightning detection before and
curiosity is getting to me. I'm wondering:

1. How does Strikefinder technology estimate range and direction to a
lightning strike (my original question)?
2. If Strikefinder technology operates in the AM band, why?
(Lightning contains many other frequency components from which to
choose.)
3. How are range and direction to/from lightning strikes determined?
(I know that up to around 1/2 wavelength, E and H fields are not in
phase. Does the Strikefinder use "Near Field" characteristics to
estimate range?)

Thank you in advance for your input.

-David