Stellar Reference Unit Images Options

[Brian Swift]

Images from SRU "Supplementary Data 2" published in:
Becker, H.N., Alexander, J.W., Atreya, S.K. et al. Small lightning flashes from shallow electrical storms on Jupiter. Nature 584, 55–58 (2020). https://doi.org/10.1038/s41586-020-2532-1

Spreadsheet sheet names for images: PJ11_Image12,PJ13_Image11, PJ13_Image12, PJ14_Image11, PJ14_Image12, PJ15_Image12, PJ15_Image13, PJ16_Image19, PJ17_Image13

A Mathematica HistogramTransform[] operation was applied after the spreadsheet data was converted to images.

JunoSRUImages by bswift, on Flickr

[Brian Swift]

One question for the group--does anyone know how much coverage the Juno Stellar Reference Unit navigation camera collected on the dark side of Ganymede?...

As far as I can tell, there have been no releases of Stellar Reference Unit data to the PDS. However, I think future SRU data will be archived based on wording in "Juno Extended Mission" section of "Report of the 2020 NASA Planetary Missions Senior Review" :

"The panel recommends that NASA work with the Juno team to support the archiving of SRU data from the prime mission. Consideration should also be given to delivering data to PDS from J􏲕uno'􏲔s Radiation Monitoring in􏲐vestigation,"

Further, from "NASA Response to the 2020 Planetary Mission Senior Review":

- The Juno mission will archive EM data from several engineering experiments which have proven useful scientifically during the PM.
- Additionally, the Juno mission has been asked to provide a supplementary proposal to PSD to archive engineering experiment data acquired during the PM that were not originally archived.

Some SRU CCD information from “The Juno Radiation Monitoring (RM) Investigation” H.N. Becker et al. (paywalled) section 2.3 "SRU CCD Focal Plane Array":

512x512 resolution
0.0325 degrees per pixel (similar to JunoCam)
17-micron pixel pitch, and 200,000 electron full well
2.7-ms integration dwell time between shifts
f( R )= a0 + a1 R + a2 R^2 + a3 R^4
a0 = 0.999432579, a1 = −0.0295412410, a2 = 0.2733020107, and a3 = −1.9368112951
time needed for full image transfer to the spacecraft, ∼ 15 minutes

In addition to the SRUs, the Advanced Stellar Compass (ASC) cameras (2 pair) are part of Magnetic Field Investigation. The Radiation Monitoring paper discusses aspects of the ASC relevant to radiation monitoring, but not imaging. The NASA Senior Review report didn't mention archiving ASC images.

Also, this post has SRU images I produced from spreadsheets in a Nature paper: http://www.unmannedspaceflight.com/index.p...st&p=247827

[NMRguy]

Thanks Brian! This is really helpful.

At a minimum, this may open up Dark Side/Planetshine Outer Planetary satellite imagery opportunities if Program Managers want to spend the money integrating an SRU-class camera into these future proposals. We'll see what the overall Juno SRU imagery collection yields on the three innermost Galilean moons.


As to the Advanced Stellar Compass sensors, I remember that the Juno team released some Juno/ACS imagery data during the 2013 Earth flyby, including a fun little video of the Moon orbiting the Earth. Resolution is much poorer than SRU data, for sure. ( https://www.planetary.org/space-images/the-...-seen-from-juno )

[Brian Swift]

Europlanet Science Congress session "Jovian Satellite and Ring Observations from the Juno Stellar Reference Unit, plus Plans for the Dark Side Perijoves"
Abstract at: https://meetingorganizer.copernicus.org/EPS...PSC2022-95.html but no images.

Also see there is an entry for SRU images in PDS, but "ARCHIVE_STATUS = PRE PEER REVIEW" so images not available there yet.
https://pds.nasa.gov/ds-view/pds/viewProfil...U-EDR-2-L0-V1.0

[stevesliva]

Neat. That abstract says that jupitershine revealed terra incognita on Ganymede.

[mcaplinger]

At a minimum, this may open up Dark Side/Planetshine Outer Planetary satellite imagery opportunities if Program Managers want to spend the money integrating an SRU-class camera into these future proposals.

On a three-axis stabilized spacecraft, any camera can do this by using a long exposure time. It's only because Juno is a spinner that it becomes so difficult. And the SRU is terribly constrained as a general-purpose imager. No reflection on it, it's a star camera and was never intended for this application.

[Brian Swift]

Just noticed link to SRU images on JPL Photojournal in MissionJuno Europa preview article:
https://photojournal.jpl.nasa.gov/instrumen...im&sort=ASC