RST Engineering wrote:

Snip

As to range, there are several methods, some of which depend on the
reflection of that hewmongous pulse of electromagnetic energy from the
surface of the earth bouncing from earth to ionosphere and back again,
creating a double pulse train from each stroke. Again, using digital signal
processing from multiple echoes you can create a "pseudorange" fairly
accurately.

Nearly as accurate, and nowhere as complicated is to "assume" a value for
radiated power from the average lightning stroke and simply do a range
predicated on the peak detected strength of the received lightning pulse.
Some will be stronger and some will be weaker, which is why all of them
don't fall directly on top of one another but form a circular pattern
perhaps twenty miles in diameter on the display. Again, microprocessors can
massage the data to toss out the responses at the one-sigma point and only
give those responses that fall in the expected range.

Now as to the practicality. I've flown a Strikefinder for almost a thousand
hours. It has YET to give me a false indication and it has YET to give me
an incorrect bearing and distance (within expected error) on a really nasty
set of cells.

I can't find a reference now, but I thought one of the other refinements
made by Strikefinder was to use dispersion as a means for distance
measurement.

Matt