There are three primary sources for the input CDIs: the VICAR image label (which contains the Event Round Robin), the GSFC observing scripts or the VILSPA observing log, and the NEWSIPS processing system. The image label is machine readable and was used as the initial source when possible. The observing scripts are more accurate and were used to verify the accuracy of the data taken from the image label. The output CDIs are determined as part of the image processing system. A detailed description of the image label contents, including the ``round robin'' series of sequential spacecraft commands, can be found in an article by Van Steenberg (1989).