Howto #14
Problem: pics_ag command line periodically updated with "possibly saturated..."

    Diagnostic :
  • The pics_ag command line is repeatedly updated with a warning message like:
    
    /export/home/pmas/dat/run28ag_040827/run28ag_01022a.fits :
    possibly saturated, corrupted, or as yet incomplete image.

    Explanation :
  • As a measure to detect and discard incomplete or corrupted images coming from the acq CCD, the polling mechanism of pics_ag is looking for certain features as a new image is coming in. If an image is falling above a threshold of 32767 counts/pixel, constant with zero variance, etc., it is presumed to be either overexposed or otherwise corrupted. Such an image is exempted from autoguiding and analysis, hence the message.

    Solution :
  • This message is nothing to worry about, it will disappear after the next ordinary (and well-exposed) exposure has been read out.