[Prev][Next][Index][Thread]
RE: (meteorobs) Re: Arietids
Trying various types of filters is an excellent idea. Those of you with access to other types of filters may discover one that works well. The ultimate question will be, "What is the signal to noise ratio?" Will the meteor's energy output in the passband be significantly greater than the sky's output in the passband? Will the meteor's energy output in the passband be great enough to be detectable by eye or electronic instruments? If so, it may be advantageous to use the filter.
I like the idea of trying it on a moonlit night too!
Finally, some thoughts on the polarizer. Since a polarizer will halve the intensity of unpolarized light, if we can assume that meteor light is unpolarized, then a meteor will loose half of its intensity (~1 mag). If we can reject any of the polarized sunlight/moonlight, then we have gained in the signal to noise ratio. Our advantage will hinge on how much of the light is polarized in the patch of sky that we are observing. Tonight after work, I'll have to check in a great little book by Minnaert entitled, "The Nature of Light and Colour in the Open Air." It may have a table or graph of percentage polarization as a function of angular distance from the sun.
Matthew
PS If you can get a copy of Minnaert's book, its worth the buying price. It is written by a physicist with a pre-WWII physics flavor,... more of a natural scientist's perspective. Its refreshing in this day of high cost physics and astronomy.