Plotted entries from OPSLOG files in NACO report AOSTRDAILY, plot 6 (data set aostrw6_HC):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2012-05-21	56068.892961	0.620573386588692
2012-05-21	56069.874382	0.557609259992754
2012-05-23	56070.915196	0.644109570175959