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Re: (meteorobs) One amateur's reaction to the 2000 Ursid results

As a 'veteran' of the 1998 and 1999 Leonids, being part of the
combined professional and amateur efforts to make the most of these rare
events, I beg to differ from Richard Taibi's assessment: Visual meteor
observations are still the baseline to which all other methods have to
measure up. This became especially evident during the 1999 Leonid storm when

   - only the visual observations by (experienced) amateurs where able
     to get the strength of the outburst (measured as the ZHR) to within
     better than 50% of what was eventually considered the true value, while

   - all the hi-tech techniques employed around the world delivered values
     that were either off by a factor of 2-3 or even more (this from automated
     or semi-automated computer analysis of intensified video), or

   - gave results that are still highly confusing, even a year later (this
     refers both to radar and radio techniques where antennae were listening
     to the radio emissions of the meteors themselves).

These bold statements above are based mostly on what I learned at the April
2000 Leonids conference in Tel Aviv (see my report in the 2nd story of
http://www.geocities.com/skyweek/mirror/186.html for some impressions) -
the most memorable moment was when a USAF representative freely admitted
during his talk that the visual amateur data obtained during the Leonid
storm were better than what the military guys had been able to achieve!

Now I'm not talking about the exciting basic science that has come out
of the professional Leonid 1998 and 1999 campaigns, esp. the airborne
ones (the spectroscopic results are totally outstanding) but about the
real-time meteor rate determination (for 'situational awareness'). Since
that had been the main reason for the USAF to fund its million-dollar
campaigns in both years, the message was clear, and the military dropped
out of the Leonid business.

For us civilians remaining, the task is now to make the best of all
techniques available, and the next best thing supporting the visual
observer is video, of course, closely followed by radar techniques of
all kinds (monostatic and bistatic). The wonderful and largely consistent
data obtained during the Leonids of 2000 show that these data sets can be
combined quite well, but there are strange discrepancies (e.g. the relative
heights of the 3 peaks). On the other hand various radar and video data
sets of the 1999 Leonid peak agree extremely well (as could be seen in a
recent MNRAS paper) and confirm a lot of fine structure and perhaps even
a periodic signal. With the 2000 Ursids, OTOH, the data sets are very
discrepant as evidenced by many meteorobs postings (e.g., why didn't the
Ondrejov radar see the outburst?) - *much* more work needs to be done!

Daniel Fischer
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