I observe a shift in time between OM and other light curves.
The timing in the time series produced by
omfchain
(files
P*TIMESR*) is expressed in seconds elapsed from a reference epoch
given by the FITS keyword
MJDREF. For data processed with
SAS v6.0 or earlier,
this reference time is not correct.
| SAS v6.0: | MJDREF = 5.08140007312960E+04 |
| Correct value: | MJDREF = 5.08140000000000E+04 |
The difference is 63.1839744 seconds.
Therefore, users processing Fast Mode OM data with
SAS v6.0 or earlier must correct
manually the
reference time keyword if they want to compute an absolute time scale. The
relative timing is, however, correct.
This bug will be fixed in the next public SAS version (6.1).
