30th Anniversary of the Voyager 1 Flyby of Jupiter Options

[volcanopele]

Today marks the 30th anniversary of Voyager 1's flyby of Jupiter. On March 5, 1979, Voyager 1 flew through the Jupiter system providing a wealth of information of Jupiter, its magnetic field, and moons. Thanks to Voyager 1, the Galilean satellites became worlds with real geology and amazing vistas. Voyager 1 also revealed Jupiter's ring system and Io's volcanism for the first time.

I've written up a longer post about the encounter with Io on my blog, which also has an animation of the flyby: http://gishbar.blogspot.com/2009/03/30th-a...1-flyby-of.html

[Bjorn Jonsson]

This is certainly extremely interesting. I tried recomputing the color balance of a Voyager 2 GRS mosaic I did back in 2001 ago but I now used calculations similar to those used above by Gordan and described in more detail in the VIMS thread. I think the color is significantly more realistic in the new version but beware that there might still be some bugs in my code so this might change slightly. Anyway, this is what it now looks like:



A smaller image showing the color in the old version of the mosaic:



The new version definitely looks more realistic in my opinion. It should be noted that I haven't done any gamma corrections.

By the way these are images of the Great Red Spot obtained by Voyager 2 on 6 July 1979 at a range of 3.8 million km. We are viewing the GRS from directly above in this mosaic so it shows the GRS' true shape better than the original images which were obtained with the spacecraft about 5 degrees north of the equatorial plane.

[ugordan]

I think the color is significantly more realistic in the new version but beware that there might still be some bugs in my code so this might change slightly.

A quick sanity check on your code would be to check a known neutral case input. If you are working with I/F reflectance data (i.e. solar spectrum divided out), then putting in a completely flat (say unity) spectrum into the calculation and illuminating it with the D65 illuminant (which is the sRGB white point), you should get a completely neutral grey RGB color as output.

If you are working with radiance data instead, you will end up with a yellowish-orange color as that is what sunlight color appears in the D65 white point. The effect would be similar to setting a digital camera white balance to daylight/overcast and taking a picture or something under an incandescent lightbulb.