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Re: (meteorobs) Re: Opik
Title: Re: (meteorobs) Re: Opik
Jeremie, the contradiction arises from the difference between a true count and an estimate. Anything above 4000/hour requires the observer to simply guess — he just can’t keep up by counting.
The Opik double-count method is brilliantly simple. Two observers watch the same area of sky. They keep track of N1, the number of meteors seen only by observer 1; N2, the number of meteors seen only by observer 2; and N0, the number of meteors seen by both observers. The probable number of meteors that actually fell is then N1 * N2 / N0.
Chris
on 4/19/02 1:05 AM, Jeremie VAUBAILLON at vaubaill@bdl.fr wrote:
Hello Chris, Rob and everybody,
This discussion seems interesting, and I have a question :
Considering :
>> I think it's even worse: the Opik method breaks down at rates above maybe
>> 1,000
>> per hour (with really good timing), but then ANY human counting method breaks
>> down around 4,000 per hour
> My maximum count was 70/minute. I'd tend to agree that
> for most observers counting would become unreliable at an observed rate of
> over 4,000/hr. Clearly some observers will be more able to deal with high
> rates than others.
what to think of reported ZHR=~ 50000 in 1833 (Brown 1999, Icarus 138) ??
Does this contradiction comes from the fact that this rate is deduced from a duration of observation of only 15 min maximum ?
Actually, I do not knonw the Opik method (and books seem hard to find...) : is it easy explicable ? Thanks.
Jeremie --
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