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Posted by: mcaplinger Jan 3 2020, 06:01 AM

PJ24 happened back on 12/26 but the spacecraft was in solar conjunction until around the end of the year and we are just starting to get the data back. With the holidays it may be next week before images start showing up on missionjuno, so stay tuned.

Posted by: PaulH51 Jan 3 2020, 12:18 PM

I'm sure they're worth waiting for

Posted by: mcaplinger Jan 3 2020, 10:39 PM

The first three images from the somewhat but not very close flyby of Ganymede (it's about 78 pixels across) are up now.

Posted by: Gerald Jan 4 2020, 01:57 AM

http://junocam.pictures/gerald/uploads/20200104/
and slightly post-processed crops thereof:

We are looking towards Ganymede's northern hemisphere.
Hershef and the nearby chain of bright crater ejecta (60 to 70°E, 40 to 60°N) are well-discernible, amongst other known features.

https://upload.wikimedia.org/wikipedia/commons/8/8a/Ganymede-JupiterMoon-GeologicMap-SIM3237-20140211.png.

Posted by: Gerald Jan 4 2020, 08:35 PM

Cylindrical map derived from #003 and #004:

Tentative names:


http://junocam.pictures/gerald/uploads/20200104a/.

Posted by: Gerald Jan 4 2020, 08:37 PM

North polar hemispherical map (azimuthal, equidistant)

Tentatively annotated version:


[edit: replaced annotated map by revised version]

Posted by: Bjorn Jonsson Jan 7 2020, 12:26 AM

An approximately true color/contrast version of image PJ24_004 of Ganymede enlarged by a factor of 3 (left) and a computer generated image with a latitude/longitude grid (right):

Posted by: palebutdot Jan 7 2020, 08:31 AM

Perijove 24 Jupiter images are now trickling in!
https://www.missionjuno.swri.edu/junocam/processing?id=7951

Posted by: Kevin Gill Jan 7 2020, 03:02 PM

First few Jupiter images processed from Perijove 24

PJ24-22:
https://flic.kr/p/2ibcqfP
https://flic.kr/p/2ibcqfP

PJ24-22 (Detail):
https://flic.kr/p/2ibi7CN
https://flic.kr/p/2ibi7CN

PJ24-19:
https://flic.kr/p/2ibeq3g
https://flic.kr/p/2ibeq3g

Posted by: volcanopele Jan 7 2020, 03:34 PM

No plume that I can see at Chalybes (two Io swaths down)

EDIT: now including the two images of Io from PJ24. Only very broadscale bright spots are visible (Surt "Regio", the bright area near 60/330, and Ra "Regio")

Posted by: Bjorn Jonsson Jan 7 2020, 11:13 PM

This is a heavily processed north polar projection map generated from image PJ24_17. In particular it has been processed to reveal features that are faintly illuminated by Jovian skylight on the nightside near the terminator. Processing images like this is now easier for me than it used to be thanks to a new empirical model of Jovian skylight near the terminator that is used when removing the effects of the varying illumination (I'm still tweaking the parameters though, therefore some post processing was necessary in Photoshop). This processing reveals what seems to be a part of the north polar cyclone very close to the north pole. Several circumpolar cyclones are also visible.

Posted by: Sean Jan 8 2020, 08:03 PM

PJ24_24 Eichstadt/Doran
https://flic.kr/p/2ic5XBa

Posted by: Gerald Jan 9 2020, 03:12 AM

Here a version of the north polar CPCs, a north polar map rotated clockwise by 37 degrees relative to 0 degrees System III to the right:

The center of the upper edge should be aligned to the pole.

Posted by: Gerald Jan 9 2020, 03:31 AM

Links to more processed versions of PJ24 images I've uploaded thus far:
Drafts:
http://junocam.pictures/gerald/uploads/20200104/
http://junocam.pictures/gerald/uploads/20200107/
http://junocam.pictures/gerald/uploads/20200107c/

Reprojections:
http://junocam.pictures/gerald/uploads/20200107a/
http://junocam.pictures/gerald/uploads/20200107b/
http://junocam.pictures/gerald/uploads/20200108/

Maps:
http://junocam.pictures/gerald/uploads/20200109/
http://junocam.pictures/gerald/uploads/20200109a/
http://junocam.pictures/gerald/uploads/20200109b/

An attempt of a map of the northern hemisphere of Io, 0 degrees longitude to the bottom:

Posted by: Gerald Jan 9 2020, 03:46 AM

Here a forth-back animation of the northern CPCs:

Noteworthy the slowdown of the angular velocity towards the center of at least some of the northern CPCs.

Posted by: Sean Jan 9 2020, 11:44 PM

Detail from PJ24_24
https://flic.kr/p/2icGQBF

Detail from PJ24_23
https://flic.kr/p/2icKj38

Posted by: Brian Swift Jan 15 2020, 11:20 PM

Animation of lens flare and Ganymede moving over CCD from PJ24_02.
Somewhat interesting to me is part of flare in lower left that gets brighter and dimmer, but doesn't change position through the spin.

At closest point in this sequence, Sun is about 2º degrees outside camera field of view.
If Sun were to be imaged by JunoCam it would only be about about 4 pixels across.
Images are displayed at realtime rate, but only cover half of a spin (the other half are just black space).

Posted by: fredk Jan 16 2020, 12:38 AM

Dust on lens? Or a reflection of something fixed relative to the lens?

Posted by: mcaplinger Jan 16 2020, 01:52 AM

Could be a glint off the solar panels or something on the panel structure. The spacecraft was more or less spinning around the sun line at this time since it was so close to conjunction, so the illumination on the panels wouldn't have changed very much during the spin.

Posted by: Kevin Gill Jan 16 2020, 02:38 AM

The first Southern Fisheye Composite.

JNCE_2019360_24C00042_V01
JNCE_2019360_24C00043_V01
JNCE_2019360_24C00044_V01
JNCE_2019360_24C00045_V01
JNCE_2019360_24C00046_V01

Rendered from the perspective of '43

https://flic.kr/p/2ifBijw
https://flic.kr/p/2ifBijw

Posted by: Brian Swift Jan 16 2020, 06:53 AM

Mike, just curious, did telemetry show any increase in focal plane temp while Sun was so close to field of view?

Also, has much analysis been done on what effect imaging the Sun would have on the CCD?
Given the1/25th Sun brightness, and spin duty cycle, I could imagine having the Sun imaged on the CCD might not be fatal/damaging.

Posted by: mcaplinger Jan 16 2020, 03:32 PM

Rather a lot. Even at 1 AU not enough energy lands on the CCD to damage it thermally. If you tried to image with the sun near the center of the detector, there is an electronic effect that could damage the sensor; see https://www.onsemi.com/pub/Collateral/AND9183-D.PDF for details. You may recall that there was an orbit with an unusual orientation that Junocam didn't image for, this was the reason.

I haven't looked at the temperature data but I don't expect anything significant.

Posted by: Brian Swift Jan 17 2020, 07:19 AM

Thanks for the link. At the time I didn't understand how keeping the camera off would prevent damage.
It looks like the tech note came out post launch, so I wouldn't expect the system to have the shutter disable circuit.
Though it's not clear to me if the damage would occur if the shutter was only pulsed some duration after the Sun had moved off the sensor.

Posted by: Bjorn Jonsson Jan 21 2020, 11:11 PM

This is an orthographic mosaic of images PJ24_23, PJ24_24 and PJ24_25 in approximately true color/contrast and enhanced versions:

The mosaic is centered on planetographic latitude 53 degrees north. North is up.

BTW I noticed a 'gap' in the PJ24 product IDs, there is an image number 38 and image 40 but it's as if 39 is missing. Is there an image PJ24_39 that still hasn't appeared at the Juno website?

Posted by: mcaplinger Jan 21 2020, 11:22 PM

We're keeping that one secret because of the big conspiracy, but you caught us.

Seriously, it still has a data gap that hasn't been filled in by DSN replays.

Posted by: nprev Jan 22 2020, 02:38 PM

Possibly OT, but has any ongoing, permanent degradation (i.e hot pixels, etc.) due to radiation exposure been noted in the imager? Just curious.

Posted by: mcaplinger Jan 24 2020, 02:07 AM

If you look very closely you can see a steady increase in warmish pixels, but nothing that affects imaging to any significant degree. At least that's what I would say, all of the images are available for anyone to examine -- we take a dedicated radiation monitoring image at the end of each pass to look for changes.

Certainly you can see a lot of transient particle hits in parts of the orbit, some orbits more than others.

As the orbit evolves the spacecraft will get more radiation dose per perijove, but so far so good.

Posted by: nprev Jan 24 2020, 08:49 AM

Gotta say, it's performed spectacularly. Thanks, Mike.

Posted by: Bjorn Jonsson Feb 4 2020, 12:07 AM

This is a time-lapse processed from five images (PJ24_13, 15, 17, 19 and 21):

These images were obtained over a period of 14 minutes. In effect they show a Jovian sunset from above.

The images have been reprojected to a polar map. The north pole is towards lower left and the prominent clouds at lower left are centered at planetographic latitude ~60 degrees north.

The original images have been heavily processed here. The contrast and color has not been enhanced (except for some changes in the dimly lit areas very close to the terminator) but the brightness has been greatly increased near the terminator. Some of the original images (especially the last two) are quite noisy and dark near the terminator and this results in some processing artifacts. Despite this, many interesting changes can be seen near the terminator as the sun sets, for example clouds that get more reddish and shadows that get darker and bigger.

A 'tweened' version is also available on Vimeo:

https://vimeo.com/389125877

Posted by: Gerald Feb 4 2020, 05:35 PM

Regarding animations: Despite the increasingly challenging observational conditions, it's still (PJ24) possible to resolve the cloud motion in the south polar region:

Each of the two frames of the blink gif is a stack of four images.

Posted by: Brian Swift Feb 4 2020, 07:07 PM

AR Quick Look globes for PJ24 (viewable in Safari on devices running iOS 13 or later) at:
http://www.mandelbits.com/arworlds.html

PJ24 Flyover animation (4K60FPS) on YouTube at https://youtu.be/3fwycMt2JX4

Posted by: Gerald Feb 11 2020, 02:44 PM

This is a partial answer to http://www.unmannedspaceflight.com/index.php?s=&showtopic=8245&view=findpost&p=246670.

The striping artifacts are most evident in the methane band images. And we have a nice methane band engineering image in PJ24.
During the cruise phase after Earth flyby, I was fairly convinced, that the striping artifacts are mostly an effect of interframe transfer smear and straylight, and studied this extensively.

In order to test for the flat field as a major cause in the less bright Jupiter environment, here an experiment with the mentioned PJ24 image, rendered into a crop of a cylindrical map:

I've run a sequence of an assumed simple familiy of flat fields with one continuous parameter ("codimension 1"). It shows, that one part of the swath shows less striping artifacts for one parameter value, while another part of the swath (but for the same CCD pixel position) shows less artifacts for another parameter value.
I'm considering this as evidence for the hypothesis, that the striping artifacts cannot be removed, at least not completely, by an appropriate constant flat field, but require (additional) modelling of interframe transfer smear and stray light. (I'm aware of the methane band filter characteristics varying with the incidence angle on the CCD. So there remains some residual uncertainty about this conclusion.)
I've been able to model part of the interframe transfer smear and the stray light for EFB images. But I failed to refine the model (within the available time) to a degree that adjustments by those model assumptions introduced less artifacts than we had without those adjustments, meaning that these effects are more complex than I first thought.
I found incidence and emission angle the most significant, but not the only contributors to illumination effects.