Juno Perijove 13 Options

[mcaplinger]

The first batch of PJ13 images have been posted to missionjuno.

[Bjorn Jonsson]

Here are my versions of image PJ13_27 ("North North North Temperate Belt"). Approximately true color/contrast:



And enhanced versions:




The subspacecraft latitude is ~40 degrees north; areas near near this latitude have been especially photogenic since Juno's arrival. Because the perijove point has been moving farther north as the mission progresses, the image resolution in this area is now somewhat higher than it was earlier in the mission.

For this image, lossless compression (Huffman) was used. The most obvious difference this makes is in the blue channel images which are always significantly darker than the red and green ones. The enhanced images are also free from the spurious 'contouring' that is sometimes visible in low contrast areas in images containing compression artifacts.

An interesting-looking feature is visible not far from the right edge at ~(1325,1120) in the 'central' image. In enhanced versions of PJ13_27 that I saw shortly after the flyby it seemed to me that this might be a big, dark and very long cloud shadow. However, this is an illusion. Closer inspection, especially in images without exaggerated contrast, reveals that this is simply a dark cloud of the same (or similar) color as several nearby features. Also it turns out that the sun is ~40 degrees above the horizon at this location, i.e. no long shadows at this location. Here is an enlarged crop from the true color/contrast image, centered on this feature:



A subset of the image metadata:

IMAGE_TIME = 2018-05-24T05:31:00.639
MISSION_PHASE_NAME = PERIJOVE 13
PRODUCT_ID = JNCE_2018144_13C00027_V01
SPACECRAFT_ALTITUDE = 7922.7 km
SPACECRAFT_NAME = JUNO
SUB_SPACECRAFT_LATITUDE = 40.6834
SUB_SPACECRAFT_LONGITUDE = 15.2981
TITLE = PJ13 North North North Temperate Belt
Resolution at nadir: ~5.5 km/pixel