IMAGE PROCESSING GALLERY
One of the biggest challenges for Juno is Jupiter's intense radiation belts, which are expected to limit the lifetime of both Juno’s engineering and science subsystems. JunoCam is now showing the effects of that radiation on some of its parts. PJ56 images show a reduction in our dynamic range and an increase in background and noise. We invite citizen scientists to explore new ways to process these images to continue to bring out the beauty and mysteries of Jupiter and its moons.
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. We 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.
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. 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”.
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.
PIA25332: Juno's Star Camera Sees Europa Close-Up
“Taken by NASA's Juno spacecraft, this black-and-white photo of the surface of Jupiter's icy moon Europa reveals a curious feature – shaped somewhat like the musical symbol for a quarter note – surrounded by a vast network of linear ridges and dark blotches. It was obtained by Juno's Stellar Reference Unit (SRU) during the spacecraft's Sept. 29, 2022, flyby of Europa.
The image shows a region crisscrossed with a network of fine grooves and sets of complicated double ridges (pairs of long parallel lines indicating elevated features in the ice). In the upper right corner are dark stains possibly linked to seepage or the bubbling up of liquid from beneath the ice. Just below center and to the right is the surface feature that takes a form like a musical quarter note. The feature measures 42 miles (67 kilometers) north-south and 23 miles (37 kilometers) east-west. The white dots in the image are signatures of penetrating high energy particles from the severe radiation environment around the moon.
The image was taken at a distance of about 256 miles (412 kilometers) over the darkened hemisphere of Europa. It covers about 93 miles (150 kilometers) by 125 miles (200 kilometers) of the moon's surface.
The SRU is designed to provide images of starfields used for attitude determination. The camera, designed for low-light conditions, has proved itself a valuable science tool, discovering shallow lightning in Jupiter's atmosphere, imaging Jupiter's enigmatic ring system, and now providing a glimpse of Europa's most fascinating geologic formations.”