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Juno Perijove 17, December 21, 2018
Gerald
post Jan 23 2019, 02:07 AM
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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.
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tanjent
post Jan 24 2019, 03:48 AM
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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.
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Gerald
post Jan 24 2019, 11:26 AM
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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.
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Gerald
post Feb 10 2019, 11:52 PM
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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.
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Sean
post Feb 11 2019, 01:36 AM
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I forgive you Gerald! smile.gif


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Sean
post Feb 11 2019, 12:23 PM
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Composite made from animation stills...





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Sean
post Feb 12 2019, 03:30 PM
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4k upscale test ( using a new method ) of Gerald's recent PJ17 animation sequence...


4k version on Youtube

...some adjustments to apply before final.


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Sean
post Feb 13 2019, 09:19 PM
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2 frame composite...





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Sean
post Feb 14 2019, 06:25 PM
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2 frame composite...







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Sean
post Feb 14 2019, 08:03 PM
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2 frame composite...






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Brian Swift
post Mar 19 2019, 12:11 AM
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My take on GRS/Oval animation using frames 34 to 40. (Large size submitted to MissionJuno)
Attached Image
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Brian Swift
post May 3 2019, 05:20 PM
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360° VR, 8K PJ17 Flyover Time-lapse posted to https://youtu.be/sWnhrBj-PI4
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nprev
post May 4 2019, 05:10 AM
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Beautiful work, Brian, thanks! smile.gif


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A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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