Fwd Re: (meteorobs) IMO METEOR SUMMARY REPORT: 11/12 Aug 2004, Lew Gramer (GRALE)

[Lewis J. Gramer]

I think Rainer meant for these comments to go out to all
'meteorobs' readers! Thanks for the feedback, Rainer. In
another private email, Rainer also mentions that there IS
a set of guidelines for reporting periods during "heavy
activity" like a Perseid peak. These are online at:
  http://www.imo.net/visual/major03.html#peaks

PS: I'll take another look at my Excel spreadsheet today,
and see what period times make sense for the activity! I
also think it may be good to make TWO separate versions
of that spreadsheet - one version for "normal" reports,
and one for higher activity like the Perseid peak (with
a magnitude distribution line for each period for one or
more of the showers observed, for example)...

Clear skies,
Lew


-----Original Message-----
From: RainerArlt [mailto:rarlt at aip.de]
Sent: Wednesday, August 25, 2004 2:01 AM
To: Lewis J. Gramer
Subject: Re: (meteorobs) IMO METEOR SUMMARY REPORT: 11/12 Aug 2004, Lew Gramer (GRALE)



On Tue, Aug 24, 2004 at 07:39:08PM -0400, Lewis J. Gramer wrote:
> [...]
> And the usefulness of my "NAMN-Report.xls" Excel spreadsheet was really
> brought home to me on this report: notice in my original report I divided
> my whole observing session into THREE EQUAL periods - each less than one
> full hour of Effective Observing Time (Teff = total time minus breaks and
> meteor recording "dead time"). As I mentioned in a prior report from this
> week, this is NOT the normally recommended way of dividing sessions into
> Periods - in either the IMO or the old AMS reporting methods.

There is no explicit rule in the IMO recommendation for period
division. The pamphlets somwhere say periods should not be
shorter than an hour. That's meant for a 'normal' observation,
no high activity. For very many observers though, the 'normal'
observation is the one of a major-shower maximum, so they get
confused. I am tempted to take that rule out of the IMO web
pages.

Let me remind all observers that small observing periods are
essential in reporting about major-shower maxima. Even if a 15-minute
period contains a very meagre number of Perseids, there may be
20 other observers covering the same period, and the total
Perseid number is fully meaningful.

It is hard to give a rule for how long periods should be.
For any major-shower maximum, periods of 15 minutes duration
will be appropriate in most cases. If short-lived features
are expected, 5-minute periods are excellent.

A couple of years ago, I really received e-mail messages with
1-hour Leonid periods and the question "do you already know when
exactly was the peak?" ...

Best wishes,
Rainer


--
Rainer Arlt  --  Astrophysikalisches Institut Potsdam -- www.aip.de
Visual Commission - International Meteor Organization -- www.imo.net
rarlt at aip.de --  phone: +49-331-7499-354  --  fax: +49-331-7499-526