[X] My Assistant

[mcaplinger]

Some of the images have been posted on missionjuno.

You will immediately notice that there is something weird about them. Yes, we know about this, and I'll say more about it when I can. In the meantime, anything people can do to process them would be appreciated. I've had some success using https://github.com/chunglabmit/pystripe

[Brian Swift]

Posted following at https://www.missionjuno.swri.edu/junocam/discussion

From the Image Processing Welcome message at https://www.missionjuno.swri.edu/junocam/processing#Welcome
"
JunoCam is now showing the effects of that radiation on some of its parts. PJ56 images show a reduction in our dynamic range and an increase in background and noise. We invite citizen scientists to explore new ways to process these images to continue to bring out the beauty and mysteries of Jupiter and its moons.
"

Being part of the JunoCam image processing community, gaining a clearer understanding of the challenges would enable us to enhance our image processing techniques. Transparently sharing technical details, insights, and ongoing analysis from the project would boost our efficiency and improve our ability to devise effective workarounds.

The following image compares green channel PJ55_72 transformed with a very preliminary model of the image corruption issue with PJ56_191 raw data:

[mcaplinger]

Transparently sharing technical details, insights, and ongoing analysis from the project...

Did you have specific questions? I can't really do anything with a request this broad. And I think you are overestimating the value of the "ongoing analysis".

[Brian Swift]

Did you have specific questions? I can't really do anything with a request this broad. And I think you are overestimating the value of the "ongoing analysis".

What causes have been considered/analyzed and dismissed?
What are the current "most likely" causes?
Is the problem before, in, or after the ADC?
Is the companding implemented in HW circuit.
And while we're at it, as-flown schematics of instrument. Particularly, path from CCD to RAM (assuming problem is known to occur before bytes reach RAM.)

Is it just a coincidence that the noise (in de-companded values) is now ~256x larger (based on just looking at green channel from PJ55 and PJ56 "radiation trend monitoring" images.)

[mcaplinger]

What causes have been considered/analyzed and dismissed?

Bad bits out of ADC, basically everything after the CCD amplifier output.

What are the current "most likely" causes?

Radiation degradation of the CCD or possibly a bias voltage supply.

Is the problem before, in, or after the ADC?

Before.

Is the companding implemented in HW circuit.

Digital hardware, see above. The problem is not in companding.

And while we're at it, as-flown schematics of instrument.

I'm sure you're aware that this is not a very realistic request.

There's a nice block diagram in https://www.missionjuno.swri.edu/pub/e/down...each_Camera.pdf that should answer many questions. As time has gone by, we've had to be more and more conservative about the level of detail we've released in the open literature due to ITAR. That said, it's more or less the same as what's described in a little more detail in https://agupubs.onlinelibrary.wiley.com/doi...29/2008JE003315 for the MRO MARCI, sections 3.3.3 to 3.3.5. I can't share the specific part numbers of any of the ICs, though.