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10 Jan 2004 13:52 utc
This meteor created a very strong reflection, leaving an
ionized trail that lasted more than 3 minutes.
JANUARY 2004 QUADRANTIDS
03-04 Jan 2004 – 24 hour plot 18:00 to 18:00 utc.
Example of the intensity at 05:00 utc on Jan 04:
14 Dec 2003 – captured at 23:40 UTC
Several meteors per minute, giving some very strong echoes.
The wide Doppler shifts (20-30 Hz) indicate many layers
of differing wind-speeds in the upper atmosphere.
(1120 Hz=Grunten, 790 Hz = Vannas, 690 Hz = Muro)
15 Dec 2003 – captured at 07:18 UTC by Tom Feierabend, near New York
Tom has captured some even more extreme Doppler shifts
15 Dec 2003 – captured at 01:47 UTC
Taken from the 6 hour plot, this shows just how intense the shower was during the night.
Note that the Muro (Portugal) transmitter switched off at about 12:50
LATE NOVEMBER METEORS
24 Nov 2003 – captured 20:30 UTC.
The “hooks” are caused by the meteors plunging through layers of atmosphere that have different wind-speeds. The layers with the highest wind-speed exhibit the greatest Doppler shifts. The ionisation trails caused by the meteors are immediately subjected to the winds around them.
[Correction: Later analysis shows that the expanding walls of the meteor trail plasma tube also exhibit differential Doppler shifts as the tube expands, which often creates complex “epsilon” shapes].
24 Nov 2003 – captured 21:14 UTC
24 Nov 2003 – captured 22:44 UTC.
I actually saw this meteor in the plot below. It appeared to be a fairly normal “shooting star”, not a fireball, traveling east to west at quite a shallow angle, with the radiant being somewhere near Orion. The visual trail faded in a couple of seconds, though as you can see, the radio trail lasted well over 30 seconds.
And an (audio amplitude) graph plot of the same event:
See the (NASA) Leonids Post Mortem Report (pdf file)
19 Nov 2003 – captured 09:40 – 10:00 UTC
19 Nov 2003 – captured 05:52 UTC
A very strong reflection!
19 Nov 2003 – captured at 05:55-06:15 UTC
18 Nov 2003 – captured at 07:20-07:50 UTC
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