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Juno, perijove 14, July 16, 2018
Gerald
post Jul 25 2018, 03:45 AM
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QUOTE (mcaplinger @ Jul 24 2018, 05:01 PM) *
...
We did some tests with lower TDI several orbits ago and will likely repeat them with the new CCD readout region, but we don't have a good model for how much this will help, and it's obviously a tradeoff between blooming and SNR.

Here is a combined and annotated image derived from #45 and #46, roughly adjusted to the CCD filter layout:
Attached Image

Rather obviously, for this southern MME sequence, the blue filter doesn't cause blooming by itself. But for TDI 64, it's sufficiently saturated to let run through excess electrons from underneath the green filter. Since the green filter is about half as sensitive as the blue filter, it shouldn't cause blooming for TDI 32. But red is a little more sensitive than green. So, it might cause some blooming. Blue could swallow the excess electrons from red, since it wouldn't be saturated.
S/N would be reduced by sqrt(0.5) for a single TDI 32 image, but a pair of TDI 32 images would have a combined S/N a little higher than a single TDI 64. It's mostly a matter of available storage. We'll find software solutions to align the lower TDI images.
It might even be possible to go a little bit above TDI 32 for southern MME, but for this, a more accurate model integration would be required, including the accurate extent of especially the red filter.
I'm presuming, that the electrons behave reasonable as they should for a CCD.
Without better ideas, I'd just suggest to test TDI 32 for southern MME, maybe together with a TDI 64, to be sure about the effect.
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Gerald
post Jul 30 2018, 10:35 AM
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In the meanwhile, some more renditions are online:
PJ14 flyby on YouTube, according MP4, scenes, and stills.
Hipassed version of cropped cylindrical maps with 180 pixels per degree, attention, files are huge!
Reprojected version of early departure images.
Cylindrical and polar RGB maps thereof, and according methane band maps.
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Guest_avisolo_*
post Jul 31 2018, 12:39 AM
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Thanks so much Gerald! My humble remix of your awesome video is available here for sharing:
https://vimeo.com/282409567
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Gerald
post Aug 4 2018, 03:18 PM
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Thank you, Avi! A sound track is something I'll need to work on. It's on my list since years. But there have always been other priorities preventing me from implementation.

The last few days, I finally found some time to take some quantitative look at the varying haze layer at Jupiter's limb.

The analysis is based on a draft processing of PJ14 image #23:
Attached Image

It's squre-root encoded. So all derived quantities in this first approach below will be derived from square-root encoded values, too.

In a first step, I've written an algorithm that finds Jupiter's limb in the draft, at least approximatly.
Here the reduced image with Jupiter's limb reduced to the green lines:
Attached Image

Things rarely work on the first attempt. In this case, it was test run #17, until the software did approximately what I intended.
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Gerald
post Aug 4 2018, 03:32 PM
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After the limb was available in an explicit way, I've used it to rectify the limb approximately:
Attached Image

There are still some random oscillations induced by the algorithm.

But the quality was sufficient to take a look at the brightness values perpendicular to the limb:
Attached Image

The trained eye may see the brightness function varying along the limb.

Looking at the first derivative makes the variation more obvious:
Attached Image

Locally, we get clearly resolved double peaks.

The same can be rendered for each of the three color channels separately:
Attached Image


This crop shows the transition from a single to a double peak of the brightness gradient:

Attached Image


Of course, a large number of samples along the limb can be compiled into an animation:
Attached File  JNCE_2018197_14C00023_limb_diagram_deriveColorMov_try17.mp4 ( 2.74MB ) Number of downloads: 222
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Bjorn Jonsson
post Aug 4 2018, 11:39 PM
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QUOTE (Gerald @ Aug 4 2018, 03:18 PM) *
The last few days, I finally found some time to take some quantitative look at the varying haze layer at Jupiter's limb.

In addition to variable amounts of haze it is also possible that the position of the limb deviates slightly from the expected position according to the 'reference' spheroid. A possible reason could be variable cloud altitudes since the bright clouds (e.g. the zones) should be slightly higher in the atmosphere than the dark clouds (e.g. the belts). I have seen possible hints of this in my processing but it is very subtle and could also be due to tiny pointing inaccuracies or even some other factors.
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Bjorn Jonsson
post Aug 4 2018, 11:44 PM
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And here is image PJ14_33 in approximately true color/contrast versions and in enhanced versions:

Attached Image
Attached Image
Attached Image

Attached Image

Attached Image
Attached Image
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Sean
post Aug 15 2018, 03:08 PM
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Forgot to post this version of early Perijove 14...







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Sean
post Aug 16 2018, 12:54 AM
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PJ14_21 / Gerald's work





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Brian Swift
post Sep 7 2018, 02:11 AM
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Pipeline updates test image PJ14_36, includes debias/flat-field correction, and new color balance.
NASA/JPL-Caltech/SwRI/MSSS/BrianSwift

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Brian Swift
post Sep 8 2018, 08:01 PM
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360 degree "VR" slideshow of PJ14 color images.
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Sean
post Jul 20 2019, 11:55 AM
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PJ14_20 update [ GE/SD ]





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