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Re: (meteorobs) Angular velocities



Just a few comments as I read this interesting thread:

I would seem to agree with George's comments here. Recording data on 
the field should be kept as simple or easy as possible to ensure 
accurate data, even among more experienced observers. It would seem 
to me that angular velocities or the 1-5 scale are about equally 
accurate, since a small level of human error is possible (even 
likely) when calculating angulars. The eye is indeed an amazing tool, 
but it has its limits over what can be accurately seen. The two 
velocity methods are what seems to me more a matter of personnal 
preference among individuals. Both work well, but neither are perfect 
in my opinion. Although I am an experienced observer, I still 
currently prefer the use of scale number velocities, just to keep 
things simple on the field.

malcolm>>
"Likewise there is the plotting uncertainty which broadens this
spread, and gives rise to a lateral probability distribution. Without the speed
you just have a fuzzy great circle."<<

Idealy, enough data and plots sent to IMO from many observers would 
minimise the plotting uncertainty from a possible new shower? On some 
nights, there may be too few observers watching, but over the years 
data accumulates. With time, enough plots and velocity estimates 
(regardless of the method used) from many observers would find the 
radiant area, and basically narrow it down.

Once a target radiant area has been found by visual naked eye 
observers, more precise methods like photography can carry on to 
shrink the radiant area into a tiny point. A camera/shutter blade is 
always extremely accurate (as long as it's properly set up), and only 
a small number of meteors caught on film are needed to locate the 
precise radiant. Does this make sense at all?

Pierre


George>>
>There are limits as to what can be gained from visually observing meteors and
>there is no need trying to be more accurate than what can be ultimately
>gained. The key is to gather data as simply as possible as long as there
>aren't any diminishing returns in the end. Making data gathering too
>complicated for any additional good is just as bad as gathering inadequate
>data than renders everything else useless.

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