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Re: (meteorobs) Leonid video observations

Hi Pete,
I guess it is difficult to give a good general advice because many things
are worth to be studied, especially when having the rare chance to record
a spectacular event like the Leonids.

I will tell you what our first plans for the 1998 (!) Leonids are:

The Dutch group (DMS) intends to setup a three station network to obtain
multi-station observations of the Leonids. This will give them the unique
opportunity to study the orbital elements of the meteoroids from the storm
filament. In addition, they are involved in Peter's airborne mission,
which stuides much more aspects of the Leonids.

In contrast, our group will probably do single station observations with a
range of different lenses to study the brightness (i.e. mass) distribution
of the storm filament in detail. We hope to get activity profiles for
different meteoroid sizes and intend at best to recalibrate the 1966
visual observations with wide angle video observations if the rates are
high enough.

Of course, for all that you need more than one video system. :-)
For a single station system as yours I would suggest the following goals:

* If you have a resonable chance to catch a meteor both with video and
radio, this might be a good choice, since calibration of radio data is a
hot topic, I think. Here I would prefer a standard or tele system with a
small field of view to make the classification easier. If the rate is
getting higher and you get problems to decide whether your radio meteor
was the same as in the video, I would prefer another aim.

* It might also be intersting to determine the activity profile of the 
Leonids and compare that with your own visual observations. For that, 
you should take a wide angle system with similar properties as you
(large field of view, lm~6.5). Especially interesting is the
question, whether the peak component that was possibly observed last
year, is witnessed again. As this peak consists mainly of 
faint meteors, a slighter higher video lm (7 mag?) might even be a better 
choice.

* The Leonids are fast and produce many bright meteors with persistent
trains. It would certainly be worth to use a wide angle system to catch
many of them and maybe record how the trains become distorted. Maybe you 
are as lucky as some guys over here, who saw fireballs with 10 and 30
minutes persistent trains in the last two years, respectively!
In every case I would be highly alarmed. If a bright fireball with a
persistent train occures I would jump up and turn the camera in that
direction to study the train in detail, whatever I lens I have on the
camera.

* As we may expect many bright meteors, you have good chances to
record meteor spectra. Of course, that needs certain preparations.

* If you intend to determine the radiant, you should choose a moderate
lens and switch the field of view several times. As you have only single
station data, an equal distribution of meteors around the radiant is most
crutial! However, maybe a double-station setup will better serve that
task.

Finally I will tell you what I intend to do that night. I usually operate
my camera with one of two lenses. The faster and long focus 0.75/65mm lens
is used once I do double-station video observations (better spatial
resolution), and the 2.0/35mm wide angle lens is used for all single
station observations.
I think you can simply do more with a larger field of view (see the
list above) ... and also get more spectacular meteors imaged. ;-) The
camera will not be guided, but I change the field of view every two hours
or so. So I have the chance to work on several tasks of the list above in
parallel.
Sirko

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Sirko Molau -- Video Commission Director
International Meteor Organization
e-mail: video@imodot net
WWW   : http://www.imodot net/video
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