[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.

[Gerald]

Thanks a lot, that's helpful information.
Provided the light shield is centered horizontally, but displaced vertically, such that the CH4 filter and the red filter are fully illuminated, this would explain the superposition of two ghosts below the primary image of the target object, and the presence of only one ghost above the primary image.
The three bright rectangular areas next to the CH4 filter may add the sharp ghost below the primary image. In contrast, the corresponding bright rectangular areas near the red filters are covered completely by the light shield.
The light shield itself might add the blurred ghost below and the ghost above the primary image. Thus far I found out, that (one of) the reflecting feature(s) adding the ghost above the primary image should be close to the lower end of the red filter.

The blue filter appears to be shadowed from some stray light in a zone next to the CH4 filter. But I couldn't yet decypher, whether that's a side effect by design to protect the CH4 filter from stray light, or whether the CH4 filter is thicker than the blue filter, and casts a shadow.

There is a large number of possibly relevant detail about the camera, but probably only a small fraction of which will turn out to be actually relevant for the calibration of the images. I presume, that a detailed plan of the geometry of all surfaces possibly in contact with non-negligible light eventually reaching the sensors together with BDRF data (including anti-reflective coatings), and the refractive indices of the translucent materials would be helpful. But I don't expect this detail being readily available or cleared for publishing. Might be, you could provide the thickness of the color filters, and the z-position (relative to the CCD) and thickness of the light shield, together with the geometry of the chamber between the CCD and the optics.
In the meanwhile, I'll work with the publicly available documents and images to narrow down the relevant detail.

[mcaplinger]

a detailed plan of the geometry of all surfaces possibly in contact with non-negligible light eventually reaching the sensors together with BDRF data (including anti-reflective coatings), and the refractive indices of the translucent materials would be helpful.

I'll see what we can release. Some of that doesn't even exist -- for example, no BRDF measurements were made for this non-radiometric instrument. The ray trace of the optics in the Junocam paper is accurate if non-quantitative.

BTW, the most rigorous attempt I'm aware of to characterize the radiometric properties of a pushframe system (including stray light) can be found in "Inflight Calibration of the Lunar Reconnaissance Orbiter Camera Wide Angle Camera" http://asu.pure.elsevier.com/en/publicatio...rbiter-camera-w (not open access, unfortunately.)