Observing daytime flares
Allen Thomson (thomsona@flash.net)
Mon, 13 Sep 1999 22:31:00 -0500
Rick Brown wrote
>>Patrice Gambaro wrote:
>> ...So I wonder, is there any special techniques to observe daytime flares
>I have looked for them a few times, and managed to see them about half the
>time. In my experience, they appeared as a simple white dot in the sky, of
>about the same color and contrast as the full moon seen in the daytime
>(though obviously much smaller!)
>I wonder if anyone has tried making this observation using a polarizing
>filter? Since skylight is polarized, and presumably the light from the
>satellite is not, perhaps this would increase the contrast. Have not tried
>this myself.
Because the reflection is off plane surfaces on the satellite, it might well
be
polarized -- perhaps in the same direction as skylight, perhaps not.
Analysis
and experiment are in order.
Also, one might exploit the blueness of the sky with appropriate filters,
depending
on the color of the reflecting surfaces of the satellite. A quick
experiment would be
to observe Iridium flares in daylight through yellow or red filters and see
if there is
a gain in contrast.
A video/CCD camera behind a revolving quadrant wheel with clear, red and
cross-polarized segments might sort much of this out.