= acm calibration procedures =


== Take acm bias and dark frames  ==

When sky surface brightness measurements are to be made with the acm we must take bias and dark frames. Here are examples of how to obtain these. 

{{{
# Take 5 acm bias frames    
% acm_bias_run 5
arg1 - number of bias images to take  
}}}

{{{
# Take 21 5-second acm dark frames    
% acm_dark_run 21 5  
arg1 - number of images to take  
arg2 - integration time (5, 10, 20) 
}}}

Taking large numbers of each type of calibration is not critical. The fixed bias pattern seems to be fairly constant, but the mean bias level floats around. A set 5 acm bias frames on any given night would be extremely useful for deriving the nightly mean level.