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Combining data from many perijoves, For images/mosaics that are not perijove-specific
Bjorn Jonsson
post Apr 6 2018, 09:08 PM
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This thread is for images/mosaics that combine data from more than one perijove pass or compare data (e.g. the appearance of specific features on Jupiter) from two or more perijoves. In other words, it is for images and related stuff not specific to a single perijove.


It is possible to use the JIRAM infrared images to attempt to guess what areas not imaged by JunoCam might look like at visual wavelengths.

Below is a montage showing versions of a mosaic of JunoCam images from perijoves 1, 3, 4 and 5. The effects of the varying global illumination have been removed. The mosaic shows Jupiter's north polar region in orthographic projection from directly above. Because the north pole is in darkness, an inverted, heavily processed and colorized JIRAM mosaic was used to fill the gap at the north pole. This represents an attempt to guess what this area might look like in visible light. Small scale details in the cloud morphology should be fairly accurate/realistic but the overall contrast, brightness and color are based partially on a visual comparison of the JunoCam and JIRAM data farther from the pole where useful data from both instruments is available. It is difficult to guess how accurate this is but it is definitely far better than leaving this area blank! The JIRAM data appears a bit different from the JunoCam data in the mosaic but this is mainly because the JIRAM images suggest that the overall color and brightness in the area very near the pole (including the central cyclone) really are different from areas farther from the pole. Another factor is that the JIRAM data is of somewhat higher resolution. Also unlike JunoCam, the difficult illumination conditions in the polar region do not affect the JIRAM images. And here is the montage:

Attached Image


The montage shows the following:

Upper left: An approximately true color/contrast mosaic of Jupiter's north polar region.
Upper right: A mosaic of Jupiter's north polar region with enhanced colors and contrast.
Lower left: The approximately true color/contrast version with a latitude/longitude grid. Latitudes are planetographic.
Lower right: A diagram showing the areas covered by the different source images/data. Unless otherwise noted the data is from JunoCam.
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Bjorn Jonsson
post Apr 6 2018, 10:16 PM
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Here is a comparable montage featuring a mosaic covering the south polar region. This is from JunoCam data; it is a mosaic of two perijove 6 images, one perijove 7 image and one perijove 8 image. The color very near the pole might be somewhat inaccurate due to the very low illumination levels near the pole in the original images. The position of the circumpolar cyclones during PJ6 was used as a reference when creating the mosaic, however this is of minor importance since their movement is negligible. In contrast, the areas farther from the pole change a lot more and seams between the different perijoves were originally obvious in the mosaic. These seams have been removed for cosmetic reasons.

Attached Image


Like the north polar montage, this montage shows the following:

Upper left: An approximately true color/contrast mosaic of Jupiter's north polar region.
Upper right: A mosaic of Jupiter's north polar region with enhanced colors and contrast.
Lower left: The approximately true color/contrast version with a latitude/longitude grid. Latitudes are planetographic.
Lower right: A diagram showing the areas covered by the different source images/data.

QUOTE (Glenn Orton @ Apr 6 2018, 09:33 PM) *
Hey, Bjorn,

May I show this at a Juno team meeting?

Do you have anything similar for the south pole (no relying on JIRAM results necessary).

You are welcome to show these mosaics at a Juno team meeting.
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