Re: [ATM] Dark Sky Meter with Motion Sensor

[Dominic-Luc Webb <dlwebb@canit.se>]

My understanding of CCD imaging and atmospheric turbulent is
that all but the fastest CCDs cannot accomplish this because
the exposure time would need to somewhere around 10 ms or less.
Sensitivity gets to be a problem. I saw on Discovery channel a
program about superfast vehicles used to test explosives (missle
technology as I recall). They mentioned a CCD camera that was
operating at a rate that immediately sounded fishy. Backtracking
their numbers and then looking around on the net, I saw that in
fact there are CCD cameras that can sample well into the Khz
and darned close to Mhz. So, it exists, but so too does the
astronomical price tag. Maybe it has something to do with how
data is acquired from the CCD more than the detector surface and
maybe the price for the chips have (or will) come down.

If you want a cheaper alternative, I have been working (slowly
because I am not an engineer) on a PMT based image dissector. The
concept was first brought to my attention by Andy Saulietis, and
upon investigating, I recognized this could prove to be an excellent
high speed pulse counting imaging strategy. That being said, the
only companies I know that build these, do so for their own specialty
imaging systems, like Leica confocal microscopes.

I maintain a link to a few sample images from an image dissector to
give some hint what is possible. I think the more critical engineering
types might actually find sanity in this concept, which I am trying
to popularize and would welcome seeing some professional engineers
within the ATMing community get involved with.

For the image dissector link, see:
http://www.megspace.com/science/stp/pmt/pmti_pap.html



Dominic-Luc Webb
http://www.megspace.com/science/stp/

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