IMAGE PROCESSING GALLERY
For those of you who have contributed – thank you! Your labors of love have illustrated articles about Juno, Jupiter and JunoCam. Your products show up in all sorts of places. I have used them to report to the scientific community. We are writing papers for scientific journals and using your contributions – always with appropriate attribution of course. Some creations are works of art and we are working out ways to showcase them as art.
If you have a favorite “artist” you can create your own gallery. Click on “Submitted by” on the left, select your favorite artist(s), and then click on “Filter”. For other tips about the gallery click on the “Gallery Organization” tab.
We have a methane filter, included for the polar science investigation, that is almost at the limits of our detector’s wavelength range. To get enough photons for an image we need to use a very long exposure. In some images this results in scattered light in the image. For science purposes we will simply crop out the portions of the image that include this artifact. Work is in progress to determine exactly what conditions cause stray light problems so that this can be minimized for future imaging.
The JunoCam images are identified by a small spacecraft icon. You will see both raw and processed versions of the images as they become available. The JunoCam movie posts have too many images to post individually, so we are making them available for download in batches as zip files.
You can filter the gallery by many different characteristics, including by Perijove Pass, Points of Interest and Mission Phase.
A special note about the Earth Flyby mission phase images: these were acquired in 2013 when Juno flew past Earth. Examples of processed images are shown; most contributions are from amateurs.
The spacecraft spin rate would cause more than a pixel's worth of image blurring for exposures longer than about 3.2 milliseconds. For the illumination conditions at Jupiter such short exposures would result in unacceptably low SNR, so the camera provides Time-Delayed-Integration (TDI). TDI vertically shifts the image one row each 3.2 milliseconds over the course of the exposure, cancelling the scene motion induced by rotation. Up to about 100 TDI steps can be used for the orbital timing case while still maintaining the needed frame rate for frame-to-frame overlap. For Earth Flyby the light levels are high enough that TDI is not needed except for the methane band and for nightside imaging.
Junocam pixels are 12 bits deep from the camera but are converted to 8 bits inside the instrument using a lossless "companding" table, a process similar to gamma correction, to reduce their size. All Junocam products on the missionjuno website are in this 8-bit form as received on Earth. Scientific users interested in radiometric analysis should use the "RDR" data products archived with the Planetary Data System, which have been converted back to a linear 12-bit scale.
Closeups of NTB and NEB
These 3 overlapping images show the intricate cloud textures and colours across the newly reviving NTB and the highly disturbed NEB. They capture a unique transient stage in the great NTB jet outbreak; the orange NTB(S) developed in recent weeks, plus turbulent streaks N and S of it. Two tiny dark spots within the orange belt are notable (one also visible in image 110).
The N. Tropical Zone is currently filled with intense disturbance resulting from the NTBs outbreak. One of the dark grey streaks which like a multicoloured caterpillar. A conspicuous loop at right looks like an anticyclonic (clockwise) circulation, but is not so distinctive in ground-based images just before and after.
JunoCam targeted the northern NEB because people had voted for a spot which was actually barge B-2; but B-2 was not in the field of view’. However, the day before perijove-3, a new white spot was discovered much closer to JunoCam’s target field by Chris Go(see next post). JunoCam just caught this on the horizon. It could develop further so ground-based observers will follow it closely.
Image 111 was taken at closest approach from an altitude of only 4147 km, so in the central region is the highest-resolution image ever taken of Jupiter. It covers a NEBs dark formation (infrared ‘hot spot’) is shown, which appears as a swathe of grey streaks. --John Rogers.