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Re: (meteorobs) Tv & leonids
At 07:06 1/10/01 , Francisco Ocaņa wrote:
>I´ve heard that you can "see" the echoes of meteors in TV when there are
>big storms of meteors. Is it posible?? In which channel do you have to
>watch the TV?? How many can you watch???
Francisco, this is merely the TV version of radio meteor observation using
distant transmitters. To answer the impication in Terry Johnson's followup
query. This is just the ionized trail of a meteor reflecting an existing signal.
The one advantage it has over the usual radio detection methods, which most
frequently use the FM radio band , is that the low frequency TV are at
alower frequency. (50-75Mhz), which is advantagious, as the reflection efficiency
is better at lower frequencies. Due to the widebandwidth of a TV video
receiver the background noise is of course much larger. You will find that
its more effective to use the TV sound or the video carrier, received
on a radio receiver. This is what the people at NASA's Marshall spaceflight
Centre do for their radio meteor detection. They use US TV Channel 4 transmitters
in various cities at distances for which line of sight transmission precludes
reception. Be warned there are other natural phenomena which can cause long
distance TV reception in both the troposphere and the ionosphere.
Tony Beresford
Adelaide, So. Australia
>
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