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Re: (meteorobs) Two question regarding meteor rates?
In message <003c01c42c2e$a75b1ae0$9600000a@HAL>, Marco Langbroek
<marco.langbroek@wanadoodot nl> writes
>
>> The ITU-R recommendation P.843.1, which covers meteor burst propagation,
>> suggests a northern hemisphere sporadic rate for August, which is four
>> times the February rate. This presumably covers both day-time and night-
>> time activity. They don't provide any reference for this conclusion and
>> it could simply be incorrect.
>
>There are a number of significant streams in this part of the years,
>including some daylight sources. Perhaps these contribute.
>
I'm wondering if you were to assume a constant meteoroid distribution,
but combine the effects of the daily diurnal variation, with its 06:00
peak and 18:00 trough, with the annual variation due to the height of
the ecliptic, you will indeed get the variation described in the ITU
document. This will peak, when the daily 06:00 peak coincides with the
ecliptics maximum height during that day. This will reflect the maximum
sporadic meteor rate, when considered meteors throughout the whole day.
However, when you only consider the visible night-time rates, you need
to combine the above factors, but only over a limited part of each day.
As the night time period is essentially half of the diurnal trough and
half diurnal peak, the above effect is largely removed and the result
will be quite a different distribution - that described in Jennnisken's
report cited - largely resulting from the height of the ecliptic.
Does this seem feasible?
--
David Entwistle
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