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Why has Cassini not done a high-rez mosaic of Titan?
stephenv2
post Jan 27 2009, 07:27 PM
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I've not be able to find a good answer to this question. High resolution visible light images of all the major moons of Saturn seem to exist but I don't see anything much over 500 pixels and not very usuable. I desperately need one for my film. I realize that the hazy world may make it seems there is not much science value in this but I'm not 100% convinced of that. Plus, I suspect a really high resolution image (say a 16-image one) would be well worth the cost from a PR viewpoint and perhaps it would reveal some interesting info as well.

I have not found any real orbital/mission reason it could not be done before Cassini is finished. Anyone have any insight?


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volcanopele
post Jan 27 2009, 07:36 PM
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The biggest problem with creating a high-resolution visible color mosaic of Titan is the blandness of Titan's atmosphere. It would be difficult to piece the images together properly if there are no real features to set as control points. And as you point out, the science basis for using all that data volume is pretty limited.

Now, I can definitely see taking more single frame visible color images. I wonder if there is enough data volume available to splice them into out cloud monitoring observations.


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stephenv2
post Jan 27 2009, 08:11 PM
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QUOTE (volcanopele @ Jan 27 2009, 02:36 PM) *
The biggest problem with creating a high-resolution visible color mosaic of Titan is the blandness of Titan's atmosphere. It would be difficult to piece the images together properly if there are no real features to set as control points.


Sure, a little challenging but certainly not a reason not to do it. I would enjoy putting that mosaic together myself. I think the real issue is per the mission planning. I mean Titan is the moon we landed on - yet we don't have good photograph. Does this have anything to do with the general public's general ignorance of Huygens? This reminds of Apollo 8 and lack of planned photographs of earth. Fortunately, astronaunts with cameras were aboard and took perhaps some of the most important pictures in history.

I know if Cassini were manned we'd have a ton of nice photos of Titan. I think it's important that we get a least one before Cassini leaves.


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ugordan
post Jan 27 2009, 08:20 PM
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You're not missing out on much. At low phase angles, Titan is just a fuzzball as almost all haze structure in visible light is invisible. You could get away with just massively enlarging a smaller image and filtering it a bit - like this one. Compare to this shot of the south pole at native resolution - no structure visible either, at the very least it's lost in 8bit color banding.

For high phase, crescent views, things are a bit different and you would be actually able to see more details with a higher resolution shot as opposed to a distant snapshot. Even then, mostly over the north pole (in this Titan season).


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stephenv2
post Jan 27 2009, 08:33 PM
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QUOTE (ugordan @ Jan 27 2009, 03:20 PM) *
You're not missing out on much. At low phase angles, Titan is just a fuzzball as almost all haze structure in visible light is invisible. You could get away with just massively enlarging a smaller image and filtering it a bit - like this one. Compare to this shot of the south pole at native resolution - no structure visible either, at the very least it's lost in 8bit color banding.

For high phase, crescent views, things are a bit different and you would be actually able to see more details with a higher resolution shot as opposed to a distant snapshot.


I do agree about high phase, though I would prefer a full body shot. But, for the film, even slight enlargements produce artifacts that wreak havoc - I learned this from my 2 minute filmout test projected on 90ft wide IMAX screen that I did in September. The enlargement you sent would simply be usable as the color artifact on rim of Titan would look awful on filmout. It's precisely the 8-bit banding issue that native high resolution is so useful to me. It greatly minimizes 8-bit artifacts and I like to keep things at 50% in an 8k frame (roughly 8000 x 6000 pixels). The 3D motion I use puts even more demands and for images that I want to fill 50% of the screen, 100 Megapixel images are ideal.

Enlargements of images beyond even 125% using the best algorithms and filters available still look bad in IMAX.

While the body of Titan is a fuzzball, the real value of the large mosaic would be the great detail of the atmosphere layers in a global view. Would be beautiful and might reveal a little science.


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Posts in this topic
- stephenv2   Why has Cassini not done a high-rez mosaic of Titan?   Jan 27 2009, 07:27 PM
- - volcanopele   The biggest problem with creating a high-resolutio...   Jan 27 2009, 07:36 PM
|- - stephenv2   QUOTE (volcanopele @ Jan 27 2009, 02:36 P...   Jan 27 2009, 08:11 PM
|- - ugordan   You're not missing out on much. At low phase a...   Jan 27 2009, 08:20 PM
||- - stephenv2   QUOTE (ugordan @ Jan 27 2009, 03:20 PM) Y...   Jan 27 2009, 08:33 PM
|- - djellison   QUOTE (stephenv2 @ Jan 27 2009, 08:11 PM)...   Jan 27 2009, 08:36 PM
|- - stephenv2   Full inline quote removed - Admin Per the manned/...   Jan 27 2009, 08:44 PM
|- - djellison   QUOTE (stephenv2 @ Jan 27 2009, 08:44 PM)...   Jan 27 2009, 09:52 PM
- - volcanopele   Looks about right, ugordan   Jan 27 2009, 08:32 PM
- - imipak   It depends whose "best" are referred to,...   Jan 27 2009, 09:53 PM
|- - stephenv2   QUOTE (imipak @ Jan 27 2009, 04:53 PM) th...   Jan 28 2009, 01:17 AM
|- - stevesliva   QUOTE (stephenv2 @ Jan 27 2009, 09:17 PM)...   Mar 17 2009, 02:35 PM
|- - stephenv2   QUOTE (stevesliva @ Mar 17 2009, 09:35 AM...   Mar 17 2009, 03:06 PM
- - Phil Stooke   Uh - 'they' have done lots of high resolut...   Jan 27 2009, 11:00 PM
|- - stephenv2   QUOTE (Phil Stooke @ Jan 27 2009, 06:00 P...   Jan 28 2009, 01:23 AM
|- - titanicrivers   QUOTE (stephenv2 @ Jan 27 2009, 07:23 PM)...   Jan 28 2009, 02:26 AM
|- - stephenv2   QUOTE (titanicrivers @ Jan 27 2009, 09:26...   Jan 28 2009, 05:48 AM
- - Vultur   The trick for making an extrapolation look right w...   Jan 28 2009, 07:56 AM
- - djellison   You've asked for insight into mission reasons ...   Jan 28 2009, 09:21 AM
- - Greg Hullender   I am kind of curious why we don't seem to have...   Jan 29 2009, 11:54 PM
- - volcanopele   The southern trailing hemisphere has been poorly c...   Jan 30 2009, 12:03 AM
|- - Greg Hullender   QUOTE (volcanopele @ Jan 29 2009, 04:03 P...   Jan 30 2009, 04:39 AM
- - Phil Stooke   For what it's worth, Voyager 1 did take high r...   Jan 30 2009, 12:05 AM
- - nprev   Just out of curiosity, has anybody developed a goo...   Jan 30 2009, 01:33 AM
- - lyford   Ah, just film a cue ball in amber light with some ...   Jan 30 2009, 03:33 AM
- - volcanopele   Okay, yep that gap is real. Again, in later NT en...   Jan 30 2009, 04:47 AM
- - Greg Hullender   Oh I don't think "annoyed" is the ri...   Jan 30 2009, 04:23 PM


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