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.
Juno's Perijove-05 Jupiter Flyby, Reconstructed in 125-Fold Time-Lapse, Revised
On March 27, 2017, NASA's Juno probe performed her Perijove-05 Jupiter flyby.
For this flyby, data volume was limited, and primarily dedicated to observations of Jupiter's polar regions.
Therefore only part of Jupiter's latitudes were covered well with close-up images.
This movie is an attempt to reconstruct the flyby on the basis of the JunoCam images taken.
Due to the gaps in good latitudinal coverage, the resolution of the movie is varying.
You may notice some surface areas of Jupiter with a clear turquoise or greensih cast.
Those aren't a Jupiter surface features, but effects of some overexposure, especially of the red channel.
On the other hand, the longer exposure improved the image quality near the terminator, including the poles the observation campaign was designed for.
The movie is a reconstruction of the period of time between 2017-03-27T07:30:00.000 and 2017-03-27T09:47:00.000 in 125-fold time-lapse.
It is based on 13 of the raw JunoCam images taken during Perijove-05, and on spacecraft trajectory data provided via SPICE kernel files.
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 25 images per second results in 125-fold time-lapse.
Resulting overlapping scenes have been blended using the ffmpeg tool.
In natural colors, Jupiter looks pretty pale. Therefore, the still images are approximately illumination-adusted, i.e. almost flattened, and consecutively gamma-stretched to the 4th power of radiometric values, in order to enhance contrast and color.
The movie starts with a reconstructed in-bound sequence approaching Jupiter from its north. Then the orbit approaches Jupiter down to an altitude of about 4,000 km near the equator.
This is followed by a transition into the outbound orbit, during which Jupiter's south polar region comes into sight.
JunoCam was built and is operated by Malin Space Science Systems in San Diego / California / USA.
Many people at NASA, JPL, SwRI, MSSS, and elsewhere have been, are, and will be required to plan and operate the Juno mission.