(meteorobs) "Julian Portik" VLF

[drobnock]

Subject: (meteorobs) Perseids VLF observations

1. For a field set up -  the loop antenna needs to be at right angles to

> the ground with the broad side of the antenna (flat end of square)
> toward the direction of the rising radiant of the shower. You may want

> to "tune" your receiving circuit to narrow the frequency range, and
not
> be open to multiple signal sources.

>>So do you think it's a good idea to tune the antenna to approx 10 KHz
or
what frequency would you suggest?

My suggestion is to stay below 10 kHz. My receiver - because it is not
designed with filters and multiple stages -- is tuned for about 3.2KHz
with a harmonic 9.6 KHZ. The establishing of its resonance was
accomplished by using a signal generator injecting a carrier and tone
into the antenna input with the antenna and  fixed capacitor in place
and with a volt meter at the out put indicating the strongest reading as
the signal generator was tuned over various frequency ranges..

> 7. For now,  until shown other wise, the signature of a meteor and
> lightning are similar.

>>The receiving circuit is able to receive lightening as I saw last last
week
(it was clearly in the spectrogram and in the sound file)
Is there anything to compare with the signal strength of meteors to test
the
circuit when there's no meteor shower?

I have no way of knowing how to answer this question. The strength of
the meteors signal is dependent on many factors -- ionization intensity
of the atmosphere, distance the meteor is from the observer, height of
the meteor above the observer and more relate to the propagation of an
electromagnetic wave through space. Even the position of the meteor to
the observer may be a factor in the meteors output signature..

You can establish a base line for your receivers output for a quiet sky.
But with other factors present, distant storms, electrical interference,
and related local noise, solar activity -- there is no established
method - to date - of measuring a meteors self generated signature,
based on its mass or visual magnitude of a meteor.

If you can you may want to review a publication called "Meteors and
Meteorites" By Martin Beech (2006). He has some calculations to help
work out the relative electrical energy that a meteor may generate.(
pages 16 to 25) and review his bibliography. This may be useful.

Good luck

George John Drobnock