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.
PJ55 Jupiter approach reconstructed from JunoCam data with parts in 450-fold and 30-fold time-lapse
This video covers the Jupiter approach portion of Juno's Perijove 55 flyby, when NASA's Juno spacecraft approached Jupiter's northern circumpolar region after the Io flyby.
The first part displays 132.5 real-time minutes starting at 2023-10-15T07:45 (including fade-in) in 450-fold time-lapse and with a field of view of 80°x45°.
After a fast zoom-in over about 15 rendered still images to a field of view of 32°x18°, the video continues with a 30-fold time-lapse. The video ends near 2023-10-15T10:40, just before the spacecraft crossed Jupiter's terminator to its night side.
The video is based on 15 Perijove 55 JunoCam RGB images (product ids JNCE_2023288_55C00041_V01 to JNCE_2023288_55C00062_V01, skipping a few). The stills of the first portion of the video are rendered in time-steps of 15 real-time seconds. The stills of the second portion of the video are rendered in time-steps of one real-time second.
Both parts are converted into a video file with a rate of 30 frames per second.
For calibration purposes, after decompanding, assembling and patching the raws from several camera artefacts, linear radiometric factors (0.734; 1.0; 3.023) were applied to the (R;G;B) channels. Those weights were derived from the PJ54 RGB sequence.
The Jupiter images have mostly been illumination adjusted and gamma-stretched to the 4th power of square-root encoding in order to enhance colors and contrast.
For each of the included raw images, the stills used for their respective video scene were rendered based on Juno's SPICE trajectory data. Those scenes were blended into a continuous sequence of stills, and finally converted into an MP4 video file using the ffmpeg utility.
The stills were processed from the raws using home-made proprietary software.