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.
Juno's Perijove-35 Ganymede and Jupiter Flyby, Reconstructed in 150-Fold Time-Lapse
On July 20, 2021, NASA's Juno probe flew by Ganymede, before she successfully performed her Perijove-35 Jupiter flyby about 15 hours later on July 21, 2021.
The movie consists of two sequences, a Ganymede flyby sequence, and a Jupiter flyby sequence.
The Ganymede sequence covers about 40 real time minutes.
Jupiter flyby portion of the movie is a reconstruction of the 4 hours between 2021-07-21T06:30:00.000 and 2021-07-21T10:30:00.000 in 150-fold time-lapse.
The movie is based on 52 of the JunoCam images taken, and on spacecraft trajectory data provided via SPICE kernel files.
Two of the PJ35 Ganymede images and 50 of the PJ35 Jupiter images have been used.
In steps of five real-time seconds, one still images of the movie has been rendered from at least one suitable raw image. This resulted in short scenes, usually of a few seconds.
Playing with 30 images per second results in 150-fold time-lapse.
Resulting overlapping scenes have been blended using a home-made software tool.
The final still images were converted to MP4 using ffmpeg.
In natural colors, Jupiter looks pretty pale. Therefore, the still images are approximately illumination-adusted before further post-processing, i.e. almost flattened, and consecutively gamma-stretched to the 4th power of radiometric values, in order to enhance contrast and color.
Like for all its previous flybys, Juno approached Jupiter roughly from north, and left Jupiter looking towards the soutern hemisphere.
JunoCam was built and is operated by Malin Space Science Systems in San Diego / California / USA.
Many people at NASA, JPL, SwRI, and elsewhere have been, are, and will be required to plan and operate the Juno mission.