"NULL" HC: Some of the FITs files seem to have some
timing issues. This is illustrated by a TIME=NULL in the file.<br>
We monitor here the percentage of OBs and the percentage of
frames affected by this problem. We only look at fringe files.<br>
The percentage of OBs is calculated by (#OBs affected)/(total # of OBs). <br>
The percentage of frames is calculated : (# number of frames affected)/(#total
number of frames). The total number of frames is the number of DITs (typically
the total number of DIT is 10000 to 16000 per OBs, the number of NULL frames
when an OB is affected is 1 or 2 out of these 10000-16000) <br>
These plots are
valid only from April 2009.