I would second what Bruce says, if I understand this correctly the
recordings are reflections of radio waves off the ionized trail of a
meteor as it passes through the upper atmosphere. The trail lasts only
for a few seconds so the reflection is very fleeting. This is compared
to radio wave reflections off slightly more lasting phenomenon such as
the daily ionization caused by the sun or the bounce off the aurora
borealis. It is like comparing the echo of a shout off a cliff wall to
the echo of the shout off a passing 18 wheeler truck. You don't get
much of an echo and it doesn't last long off the passing truck. That's
why it's way cool for a radio operator to catch the fleeting bounce off
a shooting star.
So, is it the recording of a natural phenomenon? Well, it would be like
playing rock music through loud speakers and recording the echo off a
canyon wall. The echo is "natural" I suppose because the canyon wall is
natural even though there is nothing natural about the source music.
Still, it is a very interesting event and I compliment and thank you all
for bringing up the subject and enlightening us. It's not "off topic"
for me.
Thanks,
Kevin Colver
-----Original Message-----
From:
On Behalf Of Bruce Wilson
Sent: Monday, December 04, 2006 11:07 AM
To:
Subject: RE: [Nature Recordists] The nature recording of meteor storms
Just to make it clear for those who don't know radio scattering methods,
these are recordings not of the sound the meteors make when entering the
atmosphere (they don't seem to make much sound at all, radio or aural),
but
the sounds of over-the-horizon FM radio stations that reflect off the
ionized trail in the wake of a meteors passage and become audible for a
very
short time, the duration of the ionized trail.
They aren't strictly nature recordings, but they are very interesting. I
tried this with the most recent Leonids but didn't hear anything in
Utah. I
think I should have used a more directional antenna.
Bruce Wilson
http://science. <http://science.uvsc.edu/wilson> uvsc.edu/wilson
-----Original Message-----
From: naturerecordists@ <naturerecordists%40yahoogroups.com>
yahoogroups.com
[naturerecordists@ <naturerecordists%40yahoogroups.com>
yahoogroups.com] On Behalf Of Thomas Ashcraft
Sent: Monday, December 04, 2006 10:43 AM
To: naturerecordists@ <naturerecordists%40yahoogroups.com>
yahoogroups.com
Subject: [Nature Recordists] The nature recording of meteor storms
Greetings Nature Recordists.
Part of my Science practice is the observation and audio recording of
fireballs, space dust and meteor phenomena. I operate the Radio Fireball
Observatory in north central New Mexico, US.
I thought some of you might be interested in the audio of a couple of
great and historic meteor storms as recorded by the forward scatter
method. I made a webpage of some specimen fireball reflections and
added two half hour long recordings of the peaks of the 2001 Leonid
storms.
The forward scatter method is a little too complex to explain here but I
posted links to information on the webpage.
http://www.heliotow
<http://www.heliotown.com/Phonography_Radio_Leonids.html>
n.com/Phonography_Radio_Leonids.html
Thomas Ashcraft
"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
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