#32, #33, #34:
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#35, #36, and #37:
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Image #40, processed from Gerald's drafts. Interesting to note that Oval BA ('Little Red Spot') is currently passing south of the GRS. Interesting to note that it shows very little coloration in this image, especially relative to previous JunoCam images where the system has a brownish core. It's especially interesting in comparison to the planning maps on the SwRI site, which appear to show a reddish Oval BA relative to the South Tropical Zone as recently as August. Definitely worth monitoring to see if a weakening trend is in progress.

PJ17_41 from Brian Swift output


and PJ17_40 + lightly processed


...PJ17_37 + enhanced

PJ17_38 after Gerald...

Image PJ17_36 in an approximately true color/contrast version and an enhanced version. The Great Red Spot and Oval BA are prominent:

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As has been mentioned above, the color of Oval BA has faded a lot recently. It's still slightly more reddish/yellowish than the whitish zones whereas in e.g. the Voyager images, the color of the three ovals that later merged to form Oval BA was very similar to the color of the zones. It seems to me that the color has now become somewhat similar to the color of Oval BA in the Cassini images of Jupiter (this needs to be checked more carefully though).

And this a reprojected version of the same image. It simulates the view of Jupiter from Earth:

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Draft Overview of Perijove 17


Overview of Juno's Perijove 17

Nice!

Thank you all for these stunning images - I've been mesmerised by Jupiter's beauty for 40 years and this is bringing the wonder back.

PJ17 Oval BA animation


Made with 9 frame reprojection by Gerald

PJ17_34-38


5 frame reprojection from Gerald

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Great animation! These 9 frames cover how many hours?

start / end

PJ17_32: 17:24 UT

PJ17_40: 18:07 UT

PJ17_GRS animation


9 frames / 32-40

Made from Gerald's reprojected stack.

Detail from PJ17_34-38

PJ17_35 after Gerald...

Two images showing details from PJ17_21. Compared to the original data this is enlarged by a factor of 3:

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These are approximately true color/contrast images but the brightness of the haze and blue sky at the limb has been increased slightly relative to the brightest parts of the image (the contrast in the brightest areas is also slightly reduced as a result of this). The processing reveals that the amount of limb haze is variable.

The GRS animation made me shiver. Wow. I'll be watching this again and again.

The GRS animation is awesome, especially when one considers the oblique viewing angle of the original images.

But here are approximately true color/contrast and enhanced versions of image PJ17_27 ("PJ17 Equatorial Zone south"):

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Juno's orbit is evolving and it's obvious from the PJ17 images that the viewing geometry is now significantly less favorable for imaging around the time of closest approach than it was earlier in the mission. The majority of the original PJ17_27 image data contains black space. If I understand correctly what's happening, this is going to get even less favorable but eventually things start getting better again (I suspect that may happen within a year but I haven't checked the SPICE reference trajectory yet).

Composite of JNCE_2018355_17C00038_V01 & JNCE_2018355_17C00040_V01, from the perspective/location of the former.

Been getting much better results since dropping my own renderer and using Blender.


Jupiter - Perijove 17

Here is an intermediate breadcrumb of one of the topics I'm currently working on, that's analysing the dynamics of Jovian weather systems on the basis of JunoCam image pairs:
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This is an excerpt of an analysis of pixel displacement fields, here applied to PJ17 Oval BA.
The upper left image is describing a steady vector potential, based on the two maps in the bottom row. This can be interpreted as the solenoid (divergence-free) component of a steady 2D-flow. The upper right is the amount of the first derivative of the vector potential, hence describes kind of a velocity. The other tiles try to visualize the vector potential and the derived velocity field.
Some disclaimers: I'm going to translate this into physically meaningful units. The velocity maps will look a little different after considering map distortions and proper scaling. So, be careful, when trying to interprete these intermediate products. The results are also subject to various systematic and statistical effects, which need to be specified and quantified for any scientifically meaningful interpretation. Nothing of this is substantially peer-reviewed. All errors are mine.
The answer to the frequently asked question of which software I'm using: A C++ compiler. Almost everything is proprietary and implemented from scratch on the basis of C-standard libraries like stdio.h or math.h. Runtime for the small example above was on the order of 100 CPU core hours. (I know, that GPUs exist. But I'm ready to write shader code only for simple algorithms.) For access to SPICE kernels, I'm saving s/c trajectory position data to text files using the NAIF/SPICE utility spy.exe.

Shader code? I'm afraid your conception of GPU programming is about 15 years out of date! CUDA is an ideal match for this kind of work, and even something simple like OpenMP might do well. I highly recommend that you check it out.

Thanks! I'll consider CUDA or something similar for some portions of the upcoming tasks. GPU code might make sense in some cases, multithreading doesn't. I can easily load the CPUs of a given number of computers with 100% by just starting an arbitrary number of parallel processes, if I like. The above analysis is based on 300 runs distributed over the CPU cores available for the job.

Another composite of Perijove 17 images, this time using JNCE_2018355_17C00035_V01 & JNCE_2018355_17C00039_V01. Using the camera perspective of the former.

Lots of blending and color/contrast enhancement.


Jupiter - Perijove 17

Is the great red spot really rotating noticeably in just the brief time interval of a fraction of a Perijove flyover?
I think it must be an artifact of the changing viewing angle, but Sean's GIF animation surely does give the appearance of turning a couple of degrees.

The analysis of the cloud velocity field of Oval BA in post #71 is based on two images taken within about 10 minutes. The white arrows represent the infered motion within 10 hours. The velocity field can be determined in a meaningful quantitative way from images taken within 10 real-time minutes. Sean's animation is covering a longer time interval. So, the answer is a clear yes. Here the set of maps Seán's animation is derived from. They require some additional registering. But it's well feasible.
Here is an animation of the south polar region during PJ15.
Or here a denoised MP4 version.
Here a +/-25 days steady flow extrapolation, also infered from a south polar PJ15 image pair.

... and here a preliminary analysis of a larger region, on the basis of two PJ17 images.

If a pole-to-pole pass takes about 90 minutes, it will be difficult to remain within camera range of any point in the low latitudes for more than 10 minutes, won't it? For polar regions there should be more time to register motion, but still the fact that you can infer so much longer-term dynamics from the available comparisons is remarkable. It testifies to the quality of both the optics and the processing. Very nice work.

Thanks! Near closest approach, it's very hard to retrieve any dynamical data. There, we get a mixture of dynamics and parallax. Thus far, I've been able to retrieve meaningful dynamical data from image pairs taken within six minutes, when the geometry between images isn't changing too much. For closest approach with 3,500 km above the cloud tops, the viewing angle is changing by 120 degrees or so within two minutes. I think, that for those images, it's easier to retrive 3D stereo data than dynamics. But usually, those images are too blurred and of low contrast to find significant displacement fields. At least, it's quite a bit harder to analyse them properly. As a rule of thumb, I'd say, that for ususal perijove passes, it's possible to retrieve more or less reliable velocity data outside +/-45 degrees latitude relative to the latitude of closest approach. Since this closest approach is shifting northward with each PJ pass, the quality of the data for an analysis of the southern hemisphere, including the latitude range of the GRS is improving. But I'm not yet quite at the very limit of processing the images. So, it might be possible to extend the analysis of the dynamics a little further towards the point of closest approach. I'll continue to try.

PJ17 flyby is on youtube.
Here the MP4 version, MP4 scenes, and stills.
Near closest approach, there are some visible alignment inaccuracies between the blended scenes. I hope, that you can forgive me.

I forgive you Gerald!

Composite made from animation stills...

4k upscale test ( using a new method ) of Gerald's recent PJ17 animation sequence...


4k version on Youtube

...some adjustments to apply before final.

2 frame composite...

2 frame composite...

2 frame composite...

My take on GRS/Oval animation using frames 34 to 40. (Large size submitted to MissionJuno)
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360° VR, 8K PJ17 Flyover Time-lapse posted to https://youtu.be/sWnhrBj-PI4

Beautiful work, Brian, thanks!

Collage of PJ17 images, exaggerated color/contrast.
You can download and explore the full resolution (21920-by-15334) image from Flickr.
PJ17 Jupiter Image Collage, Exaggerated Color/Contrast by bswift, on Flickr

Mission extension requested for close flybys of Io, Europa, and Ganymede. Keep your fingers crossed.

https://spaceflightnow.com/2020/10/12/juno-...jupiters-moons/