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Re: (meteorobs) Joe Rao's summation of the 2002 Leonids
>> There's definitely a significant under-performance from the
predictions
>> here!
>>
>> Mike
>
>There is a major assumption here that the correction factors for
radiant
>elevation actually apply to the Leonids. I know Hartwig Leuven has
>looked at the elevation correction for the 1999 Leonids, but it would
be
>useful to derive better correction parameters from such observations
as
>Mike's rather than rely on derived (or theoretical) parameters based
>on much smaller number statistics.
From the 1999 IMO Eurasia data it was evident that people observing
with the radiant
low in the sky saw much less meteors than would have been expected
from the
standard 1/sin h correction. The dependence appeared to be pretty much
linear and
was ZHR = 3021 + 34.7 * h radiant (deg) for the 1999 Leonids. However
the minimum radiant altitude used was about 18 deg if I remember
correctly, so Mikes 8.5 deg are a bit out of the
range of my 1999 fit.
The effect was quite pronounced - from this fit the ZHR would have
been:
radiant altitude ZHR (1999 Leonids)
0 deg 3021
8.5 deg 3315
16 deg 3576
45 deg 4582
60 deg 5103
90 deg 6144
In fact the Leonids with their huge numbers give an excellent chance
to study the dependence of ZHR on radiant altitude.
Hartwig
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