Clear Sky Detector

[Tom Droege <tdroege2@earthlink.net>]

It is about to become the Clear and Dark Sky Detector.   I just have to get 
a part.

The Clear Sky Detector is working good enough that I can use it to sort 
data as it is being taken.  Tonight I will take data set up so that I use 
the Clear Sky Detector to decide whether to open the shutter or not.   The 
weather looks promising.  There will be clear sky and clouds.

This will take dark frames when the sky is not clear.  One more thing is 
needed, then I can just turn on at dusk and run.

This is a measure of darkness.  I am working on a three state circuit.

State 1.   clear AND dark
State 2.  NOT clear AND dark
State 3.  NOT clear AND NOT dark

The data system can then decide on whether to take darks, objects, or not 
store images.  I will then just turn on at dusk and let the Mark IV decide 
what to do until dawn.

Paul Bartholdi made some nice suggestions for the detector.  One was to run 
closed loop and the other was how to do better insulation.  I will 
incorporate both ideas in the next version.  I am tired of software.  It is 
nice to have an opportunity to do what I really do best.  Invent little 
circuits to measure things.

Tom Droege