(meteorobs) IR Signature of Meteors in the near IR

[Ed Majden]

Hello Bob:
	I saw your original post, but isn't recording meteorite impacts on  
the dark side of the Moon at night a different kettle of fish?   Has  
one ever been recorded on the sunlit side, I don't think so!  The big  
problem with our all-sky cameras is the Sun scatters light on the ccd  
frame blotting out around 1/4 of the frame.  The auto iris in the  
security type camera used, also reduces the sensitivity of the camera  
so the ccd is not damaged by the strong sunlight.  Possibly, using a  
mask that would blot out the Sun may help improving the situation a  
bit.  Filtering out transmission to a specific region of the  
spectrum, i.e. near IR region, will also reduce overall sensitivity.   
I'm not sure if low velocity fireballs, the type that may drop a  
meteorite would have strong emissions in the near IR region.  I could  
be wrong about this but I think this is correct.  See: Astron.  
Astrophys. 279, 627-645 (1993) A fireball Spectrum Analysis by Jiri  
Borovicka.  Too bad these Lunar impacts are so faint as I would love  
to get a spectrum of such an impact! ;-)
Ed


On 27-May-09, at 2:12 PM, bob71741 wrote:

> Ed - I posted a link for the usage of a Wratten 87 filter and CCD  
> video camera used to record meteor impacts on the moon. I realize  
> that this is not exactly what Thomas wants to do since he is  
> interested in imaging the meteor trail, but if you can image the  
> impact,in IR, on the moon, then imaging meteor trails in the  
> atmosphere during daylight may be realizable too.
>
> Below is a copy of the Allan Kimble dialog. Please note that Allan  
> is a scientist, not an amateur, so I would have to place some value  
> to his experiences. Also note that he wants to capture  
> spectroscopic images of the impact as well.
>
> Thanks for the opportunity to write. I began filming meteor impacts  
> on the moon in 1997 using CCD cameras and long-pass near-infrared  
> filters. I was successful during the Leonids of 1997 in capturing  
> several images of the impacts on video -- some simultaneous. For a  
> while, I had posted them on a website, but they drew no great  
> attention. Since then, I have developed several smaller camera  
> systems for imaging in the NIR portion of the spectrum between  
> 850nm and about 1100nm. What I have found is that electronic noise  
> lasts, at most, 2 video frames. I have been able to see impact  
> flashes lasting between 30 and 45 video frames by using the NIR  
> portion of the spectrum. I published a couple of articles in the  
> Northeast Florida Astronomical Society newsletter (Skywatch)  
> regarding my findings and the methods of constructing NIR CCD  
> systems. The advantage is that I can make observations in daylight  
> without much interference from the sun. The original video was  
> obtained using a 1! 50mm f/13 r
> My eventual goal is to be able to spectroscopically image the  
> impacts to see if there is a correlation between the spectral light  
> emissions and the compositions of the meteor and the soil where it  
> impacts -- a kind of remote lunar geology.
>
> Allan Kimble
> Sr. Scientist
> Microscopy & Spectroscopy Laboratory
> Vistakon, Johnson & Johnson Vision Care
> Jacksonville, FL
> Tel. (904) 443-3020
> Fax (904) 443-3433
>
> Regards
> Bob
>
>
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