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Re: (meteorobs) Re:

Hi Sid,

    the 'hearing' of meteors is not actually a signal that the meteor itself
makes.  It is something called meteor scatter.  Amateur radio operators, and
others, realized decades ago that the trail of ionized gas that makes up the
meteor trail we see would also reflect radio signals in the VHF and (to a lesser
extent) UHF range.

    to listen to a meteor involves setting up, at a minimum, an antenna and a
receiver that is tuned to a strong VHF transmitter that is beyond the line of
sight but not too distant.  For example, listening for a FM broadcast station
(in the lower VHF channels), that is a few hundred miles away, a station that
you could not normally receive.  A meteor that occurs at the right place between
you and that station will reflect  (for a few seconds) the signal and you should
be able to 'hear' the signal from the transmitter.

    This mode, called meteor scatter, has been used by radio amateurs for
decades, and some remote data government and commercial systems use it (eg.
Western Union - for collecting meteorlogical data from remote automated
stations).  The meteor itself isn't heard, but its presence is detected by the
reflected radio signal.

    It is a bit of a science itself, there is an amateur meteor detection (by
meteor scatter) network operating (some of them I see are on the meteorobs
list).  They have automated the detection and counting process and worked out
ways of reducing the errors in the count that may be caused by other radio
propagation modes.  If this aspect of meteor counting interests you then a short
posting on the meteorobs list asking for more information should get you a
reply.  Myself, I've restricted my meteor scatter work to two way amateur radio
work on 144 MHz - best distance covered in a two way meteor scatter contact is
about 1500 miles.

    Gander?  Gander is located a little east and north of the centre of
Newfoundland, the most easterly province of Canada.  Gander was originally built
as an air base just prior to WW2.  It was a departure point for many military
aircraft crossing the Atlantic during the war.  Currently the airport services
many commericial and military aircraft as a refuelling point for trans-Atlantic
flights.

    I'm sending this reply from work and I don't have my signature file on this
computer.  Check one of my previous postings and at the very bottom of my
messages you should find my signature file which has my lat. & long.

    Feel free to drop me a note if you have any further questions.

                                    Ron (in Gander)

CartoonSid@aol.com wrote:

> Hello,
>    Very interesting! Thanks for that information! Two Stupid questions, Ron:
> What do they sound like and where is Gander?
> -SID!
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