[X] My Assistant

[Gerald]

This is now a first step of a somewhat sophisticated analysis of the ghosts, the success of which is to find out.
The ghosts are best feasible outside the bright Earth. So I've masked all efb12 subframes to just show the ghosts in front of dark background.
Example:

This is the average of all these masked subframes, constraint to the non-black pixels:

This average shows remnants of the source images. Most of this can be averaged away by decomposing the image in a horizontal and a vertical mean brightness function.
For averaging, the brightness values are temporarily gamma-corrected with gamma = 2, considering the square-root encoding of the raw image.
The two functions can then be composed to result in this mean ghost image:

This image is intended to serve as a 0th approximation of a flatfield for the ghosts.