When a meteor strikes Earth’s atmosphere it decelerates rapidly.
The ram pressure created by Earth’s atmosphere causes the meteor
to burn up at extremely high temperatures creating the bright
“shooting star” that we are all familiar with. This process also
ionises the air along the trail making it possible to reflect
radio waves. |
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Utilising a high powered VHF radar signal, we are able to detect
reflected radar waves from these ionisation trails. Because the
meteor is moving, the reflected signal is shifted in frequency,
this shift being heard as an audible ping by the station
operator. |
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Our system translates the reflected wave into three main
parameters - amplitude (strength), frequency shift (Doppler
shift) and decay time. This helps us determine the relative size
of the meteor strike (vertical scale) and the relative
approximate speed and deceleration (amount of shift and width of
the trace). |
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This work is licensed under a Creative Commons Attribution 3.0 Unported License. |