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(meteorobs) Are Sporadics Constant?
Dear Meteorobs Net:
Our radio observatory is at the point where we are collecting solid data 95
per cent of the time. System specifications and data for January, 2000 were
posted to Meteorobs Net on Fri., Feb 18, 2000 and in the Meteorobs Digest
V3, #298.
It appears that our next step in data reduction is to determine the number
of background sporadics and subtract this from total reflections observed.
Presumably the residual will be attributable to meteor showers.
It may be, however, that determining background sporadics will not be
trivial. Unlike the situation with visual observations, we have no easy way
to determine if a given reflection is due to a sporadic or is part of a
stream/shower.
This occurs because we collect no data on the radiant. We only determine
total activity as seen by our directional antenna. It will respond to any
signal which obeys the laws of specularity. That is, it will pick
up any signal where both the transmitting and receiving antennas can both
"see" the meteor trail at the same time, and where our antenna is at the end
of the path where the angle of incidence of the VHF signal upon the meteor
trail is equal to the angle of reflection. On average, this accounts for
roughly 3,000 meteor events in an normal 24 hour period.
Several question arise with regard to this:
1. If we are able to determine sporadic activity for a given hour during
the day, or month, are these data valid for the same hour of other days,
months, and years? That is, the level of sporadic activity constant for a
given hour, within statistical limits? Are there monthly variations in
sporadics that are statistically significant? How about yearly variations?.
We know, of course, that there is a cyclical pattern of radio meteor
activity over the 24 hour period due to the earth's rotation and its path
around the sun. Our data clearly show this 24 hour activity pattern.
2. How do we actually determine background activity? Some meteor showers
appear to be characterized by very low activity over many days. How can we
be sure we really are looking at sporadic activity (true background "noise")
without contamination by weak and/or even unknown long term meteor showers ?
I would very much appreciate input on the above questions, along with any
suggestions on literature that might deal with this.
Regards, John Meyer
Van Andel Creation Research Center
Chino Valley, AZ
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