Re: Measurements file as input

Posted by karenacollins on Apr 22, 2023; 2:09am
URL: http://astroimagej.170.s1.nabble.com/Measurements-file-as-input-tp2216p2222.html

Only the columns you want to detrend against are needed. Detrending is not required. For instance, airmass is probably the most used detrending parameter. If I recall our last conversation about detrending correctly, you are not detrending transit observations. You could still detrend those in AIJ, but you'd need sections of data that you expect should be flat within the lightcurve scatter (similar to the pre-ingress and post-egress baseline for a transit light curve). Other columns that are sometimes useful for detrending are sky background, FWHM, x-center, y-center (of a star on the detector), and time. Beware of fitting too many detrending parameters in AIJ. You can flatten any lightcurve with too much detrending. If you only have short segments of equivalent baseline, compared to the overall lightcurve duration, you should consider not detrending, or use airmass-only detrending. In all cases, I'd limit to a couple of detrend parameters that are justified by the BIC numbers that the AIJ fitting panel provides.