A simple receipe to measure the noise:

Collect 10 darks at shortest exposure (3.227s)

Subtract last 34 pairs from each other
Dark10Dark9, Dark9Dark8, etc

imstat with lo=100 hi=100, to get rid of outlayers

Divide average std number by sqrt(2) and multiply by 4.25e/ADU (gain)

If number is less than 20erms, the noise is within specs.

If the number is more than 20erms, ask moutain support to

check that the cables and ground strap are welltighed and perhaps ask them to move the cables.

Switching the motors for the filterwheels OFF & ON might help too.

Measure the noise again, and again...
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February 21,2007