Re: TASS Cameras and rain.

[Tom Droege <droege@wwa.com>]

At 12:50 PM 5/5/98 -0400, Shawn Dvorak wrote:
(snip)
>
>The best way would be to automatically detect clouds (and therefore the
>chance of rain).  And, attempting to do photometry with any appreciable
>clouds present is a hopeless task, so it's better to shut down for the
>night anyway.  I know that I personally would not want to get up every hour
>or two to peek out the window, and that's certainly not the direction that
>TASS wants to go.
>
>So how do you detect clouds?  I've seen a description somewhere of a simple
>cloud sensor that uses the fact that during a clear night the sky is much
>colder than on a cloudy one.  Thermoelectric sensors are pointed towards
>the sky and the ground and the resulting differential signal gives an
>indication of the sky's temperature, and therefore its clearness.

Yes, this is Jerry Gunn's scheme for their remote observing station.  I
like it and plan to add it to the Mark IV.  It turns out that I have one
spare ADC channel, so it will be easy to add.  

Tom Droege