Occasionally the CCD electronics cause a "bad column"- a column of high signal running through an otherwise fine image. Reviewers will see bad columns in most, if not all, of SPACEWATCH®'s images - all CCDs have some bad columns. Due to the high signal, the lack of the "fuzzy" profile and the perfectly vertical/horizontal nature of this flaw, a reviewer will find bad columns easy to recognize. Bad columns do not need to be reported.
NON-REPORTABLE: Bad Column
CHARACTERISTICS:
Sharp, perfectly vertical or horizontal line with high signal level relative to background. Typically runs the length of the image. Defects like these will tend to be in every single picture taken with the same CCD but will 'shift' in the image due to pointing changes.