Meridian flip option

[hrmobservatory]

I am familiar with the meridian flip option which re-sets two sections of the light curve together after a meridian flip.  This is a process that is designed to be used only once per session of course.  I was wondering if there is a similar option to 'rejoin' the light curve more than once during a session - for example if the mount gets disturbed by weather, bumps, etc.  Would it be possible to use the meridian-flip option itself more than once per session?

[karenacollins]

There is no convenient in-built way to handle multiple shifts in baseline. The only workaround I've thought of so far is to use meridian flip to detrend the largest shift first. Save the corrected column to the measurements table using the Add Data button on the left side of Y-data panel. Then move the Meridian Flip marker to the second shift and detrend the saved lightcurve again. This is not an ideal approach because you really need to be fitting both shifts at the same time, so there will probably be some excess residuals using the work-around approach. If there are very large shifts in multiple places, then you may have to use a spreadsheet program to shift the individual segments manually first to get them close, and then use the iterative procedure above to fine tune the offsets.

If other users have found a better approach, please let us know here (I am not a frequent user of the MF option).

One final comment. If you are having to fit many offsets, it would be worth considering whether the detrended results are actually constraining astrophysical brightness, or if you are just forcing the lightcurve to fit a straight line or transit model.

Karen

[hrmobservatory]

Thanks Karen, I will try that.