Voyager mosaics and images of Jupiter, A fresh look at some ancient stuff Options

[Phil Stooke]

This paper:

Synnott, S. P. "Orbits of the small inner satellites of Jupiter." Icarus 58, no. 2 (1984): 178-181.

probably has the information you need to identify the moon.

Phil

[jccwrt]

Thanks for the tip! I did manage to track that paper down, but it appears that this wasn't a listed observation. However, at this point I'm leaning towards Amalthea, since it appears to be more consistent with the shadow's size than Adrastea.

[jccwrt]

Another mosaic of Jupiter's southern hemisphere, capturing some white ovals and some turbulence they're creating in their wake.


South Temperate Zone Ovals and Turbulence by Justin Cowart, on Flickr

[Ian R]

Lovely stuff, Justin!

[jccwrt]

Thanks, Ian!

Here's a narrow-angle mosaic of Jupiter's cloud tops about 10 hours prior to closest approach. To me this looks like one of the last high-resolution mosaics of Jupiter's cloudtops, after this Voyager switched to targeted observations and support imaging for a little while, and the phase angle was rapidly worsening so many narrow-angle images taken a few hours later ended up severely underexposed. The color was taken using orange and violet images from a wide-angle color set that was taken simultaneously.


Voyager 1 At Jupiter Near Closest Approach by Justin Cowart, on Flickr

[Astroboy]

UV version of the famous Voyager 1 GRS zoom movie. I believe these specific images haven't appeared online before in the form I've presented them in:

[Ian R]

Wonderful!

[jccwrt]

Excellent work!

[Astroboy]

Thanks guys! It really means a lot to be praised by big leaguers like y'all when my processing capabilities are this limited; basically all I can do at the moment is take Planetary Rings Voyager and Cassini .jpegs and stabilize the targeted object in Final Cut Pro manually, frame by frame, because I can't access any professional photo editors and have no idea how to write command prompts. Plus I use a Mac, and maybe I haven't done enough reading but that also seems to limit the number of utilities potentially at my disposal.

If I could have one question answered, it'd be this: how do I know I'm mixing differently filtered images correctly? I know which images are supposed to fill in for which RGB channels, but I have no idea how much of each filter I'm supposed to mix, and so I've had Uranus come out looking white and basically like a cue ball, Neptune looking pale red, Saturn looking slightly purple, etc. And I've been using the highest level processed images - the cleaned up ones with geometrical corrections and calibrations. I know stuff like Voyager images will never feature the kind of color humans would see due to the wavelengths chosen for some of the filters, but I just get the feeling there's a proper way for these filters to be combined and I'm not doing it, because my color keeps coming out like nothing I've seen on here or anywhere else.

I'm not interested in getting color that is completely accurate to what a human eye would see, or in cleaning up images any more than they've already been cleaned in the processed versions, or in interpolating a very short, choppy series of frames - I just want to be able to stabilize and animate image sequences with color that is authentic to the data, using synthetic green channels if necessary. Then I can work on finding a way to warp the images to align different filters more accurately and create animations out of multiple mosaics!

[Ian R]

Astroboy,

I wish I had the time to write a more detailed response, but if you need a helping hand to guide you through the process of producing color composites from archived data, you can't do much better than going through Emily's wonderful series of tutorials:

http://www.planetary.org/explore/space-top.../tutorials.html

Good luck!

[elakdawalla]

Thanks, Ian, but Astroboy's question is beyond what I cover in my tutorials and is something I've had problems with on Voyager data as well. It's possible there are scaling factors and offsets in the calibrated data that are specified in the headers but are not getting applied when you do whatever you do to open the images. That's what I'd look at first. Astroboy, can you point to an example of a couple of files you're trying to use and are having color problems with? Since you mention JPEGs I wonder if you are downloading the "Browse" versions of the images, which are automatically contrast-stretched, instead of the archival versions.

[Herobrine]

Modified Astroboy's nice GIF by filling in the missing pieces of Jupiter to give it more visual continuity. The 'filled-in' parts are not accurate; I just used garbage that looks decent in motion.
(Click for GIF)

[Gerald]

... I just want to be able to stabilize and animate image sequences with color that is authentic to the data, using synthetic green channels if necessary....

In a somewhat similar scenario M.Caplinger suggested to interpolate the green channel. Depending of the wavelengths passing through the filters, some appropriate weights may be recommendable.
With more channels available, interpolation with 2nd or 3d order parabola might be possible (I've never tried this with colors).
Higher-order polynomials oscillate too much to be useful.

[jccwrt]

A 3x2 mosaic of a barge in the north equatorial belt. It's a narrow-angle clear filter mosaic, colorized with violet, orange, and synthetic green wide-field images. Taken on March 4, 1979 at a distance of approximately 157,900 km.

[Astroboy]

I put together 36 consecutive wide angle orange frames of one longitude from V1's 2x2 mosaic sequence and got another "zoom movie" I don't think has appeared anywhere before: