New Hi-res Jupiter Maps from Cassini Options

[Tom Tamlyn]

--><div class='quotetop'>QUOTE(Toma B @ Mar 27 2006, 09:07 AM) </div><div class='quotemain'><!--quotec-->
WOW!!!
5 years after flyby...

Cassini\'s Best Maps of Jupiter
[/quote]


Robert Mitchell, Cassini misssion manager, made some interesting comments about Cassini's Jupiter observations in a Von Kármán lecture delivered before orbital insertion. He said that a substantial amount of Jupiter data was languishing unread in storage.

He said in a joshing sort of way that he had embargoed further review of the Jupiter data until the instrument teams had submitted their cruise sequences. In a more serious tone of voice he said that the data were untouched because there was no funding for reviewing them.

It was just a passing comment. He could have meant that the data were lying around in the PDS waiting for someone to get around to reading them.

However, I thought that he meant that they were inaccessibly locked in raw transmission data for want of funding to extract them, so that even a scientist with time and budget to spare couldn't use them. (I gather that NASA doesn't routinely release the raw data, but it would be interesting to know.)

TTT (dunno why the quote is messed up)

This post has been edited by Tom Tamlyn: Mar 29 2006, 10:53 PM

[scalbers]

Also the color balance of my map is probably more realistic, at least compared to what Jupiter looks like to me through a telescope. However, Jupiter's color is somewhat subjective.


Several renderings based on these maps can be seen on my Jupiter page.

Hello Bjorn,

I was wondering if there's any simple way to modify the colors of some of the Cassini Jupiter releases to make them appear like your more realistic color renditions?

[Bjorn Jonsson]

Since I did my map from calibrated PDS images the details of the processing will be different but here is a quick and dirty way of modifying a well known image:

Replace the red channel (CB2) with a new synthetic image: CB1syn = 1.106251 x (0.774 x CB2 + 0.226 x BL1)
Combine this with the green and blue channels into a new color composite.

Modify the color balance of the color composite to make the NEB whitish by multiplying red with 1.022 and green with 1.095.

IMO this results in some improvement but the colors are not identical to my map. One reason is that the calibrated blue PDS images are darker than the blue image in this example so you'll need to vary the exact values of the parameters used when making CB1syn (probably increase the weight of CB2). When making the map I had to make a synthetic green color channel but it was close to the average of CB2 and BL1 so I didn't replace the green channel in this example (I think in the CICLOPS images the exact average of CB2 and BL1 is used for green).

I'm attaching the resulting image.

Attached thumbnail(s)

 

[djellison]

Bjorn - time to bitch slap the BBC
http://news.bbc.co.uk/1/hi/sci/tech/4860912.stm

Doug

[scalbers]

Thanks Bjorn for the expert advice. I tried this out on the latest Cassini map pretty much as you stated it and posted the result on my website. Any opinions for further adjustment? I'll have to try some telescope observations this spring to check it out.

http://laps.noaa.gov/albers/sos/sos.html#JUPITER