Re: How to keep FITS header when stacking?

Posted by karenacollins on Aug 06, 2017; 9:10pm
URL: http://astroimagej.170.s1.nabble.com/How-to-keep-FITS-header-when-stacking-tp725p726.html

Hi Luca,

When images are combined using underlying ImageJ functionality (i.e. the "Grouped Z Project" feature), the FITS header information is not copied forward or adjusted as you have discovered. Maybe someday I will find a way to work around that, but for now we are stuck with the current functionality.

Since you are doing photometry, another approach is to run photometry on the full (unstacked) image set. Then in Multi_Plot, use the "bin" feature to combine the photometric data to reduce the light curve scatter. The "bin" feature not only combines the photometry, but also combines the time of the individual photometric points.

You can also use the fits header editor:

to add back a hand-calculated EXPTIME and DATE-OBS keyword and associated values, but that would likely not be reasonable here if you are processing 10's or 100's of images. If you do this, AIJ will add all of the other appropriate file description related keywords when the file is saved (i.e. # 1-8 below).

Karen