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Unmanned Spaceflight.com _ Cassini's ongoing mission and raw images _ Rev 148 - Apr 29-May 30, 2011 - Titan T76

Posted by: Juramike May 6 2011, 03:12 AM

RGB composite of May 3, 2011 WAC images. Tweaked to get more sharpness (see flickr http://www.flickr.com/photos/31678681@N07/5691754011/ for processing details).


Posted by: Juramike May 14 2011, 02:55 AM

Surprise! An image of the southern hemisphere of Saturn reveals a South Temperate Zone storm! Methanovision [MT3,MT2,CB2] composite:



As far as I am aware, this southern disturbance was first spotted on May 10, 2011 by Efrain Morales (Puerto Rico) using an earth-based telescope: http://www.jaicoa-observatory.com/Sat_10_05_2011_0208ut-EMo.jpg

Posted by: Juramike May 14 2011, 03:35 AM

RGB composite of May 12, 2011 southern hemisphere image using RED, GRN and VIO images with some serious channel mixing done. The oval storm is dark in visible wavelengths, with a brighter surrounding ring of clouds.


Posted by: Juramike May 14 2011, 12:58 PM

Enhanced constrast of the CB2 image ("Wart-o-Vision") shows all the little bumps an knots in the Southern hemisphere in the overlay (and deliberate non-blend) of two frames taken several hours apart (a smaller storm can be seen to the E):




Animated blink of the two frames shows cloud motions and what looks to be a clockwise (cyclonic in S hemisphere) motion of storm oval:



[Animated GIF: click to animate]

Processing details on flickr.

Posted by: Juramike May 14 2011, 05:32 PM

Abstractly beautiful...


Posted by: ugordan May 14 2011, 05:40 PM

Lovely. Looks like a painting.

Posted by: Juramike May 14 2011, 05:43 PM

Thanks! When I was looking at the raws I immediately thought of American artist Georgia O'Keeffe.

Posted by: Juramike May 17 2011, 12:56 AM

Low phase view of Saturn, in RGB and Methanovision infrared composite on May 15, 2011. The storm center is the smudge in the upper right near the terminator.


Posted by: Ian R May 17 2011, 06:51 PM

Great work Mike! wink.gif

I couldn't resist doing my own version of the CB/G/B composite:


Posted by: S_Walker May 18 2011, 04:10 PM

I also put together a CB.G.B composite of the 5/15 data. What is extremely interesting with these images is that while the spacecraft’s geometry is poor to look for spokes, note the crepe ring shadow has a distinct thinning about 1/3 of the way towards the left from the center of the globe. This is real and rotated with the rings between each exposure. Very distinct evidence of "spokes" actually thinning the region, I'd venture to guess.


The exposures were captured through the CB2, G, and B filters. Cloud features were warped slightly to compensate for the planet’s rotation between exposures.

Posted by: ugordan May 18 2011, 06:59 PM

QUOTE (S_Walker @ May 18 2011, 06:10 PM) *
Very distinct evidence of "spokes" actually thinning the region, I'd venture to guess.

I would think those are bright clouds peeking through. I though spokes are virtually non-existent in the C ring?

Posted by: S_Walker May 18 2011, 07:19 PM

QUOTE (ugordan @ May 18 2011, 02:59 PM) *
I would think those are bright clouds peeking through. I though spokes are virtually non-existent in the C ring?


Not sure, but did say I was guessing. They also show nicely on the NAC images from the 13th that Mike posted a few days ago.

Posted by: Juramike May 19 2011, 03:19 AM

Cassini MethanoVision composite of Saturn on May 16, 2011:


Posted by: Juramike May 19 2011, 03:35 AM

Two frame blink animation of May 15 and May 16 images coordinated on key features in the tubulent wake region. The storm is moving W relative to the wake turbulence. Parts of the wake can be seen to rotate counterclockwise.


[click to animate]

Posted by: S_Walker May 19 2011, 11:32 AM

How would I find out the exact times certain images were recorded? For example, images W00067528.jpg and W00067533.jpg appear to have been recorded one Saturnian day apart. I'd like to measure the movement of features between the two images, so exact image times become important.

Posted by: S_Walker May 19 2011, 12:11 PM

Animation of CB2 WAC images recorded 5/15 and 5/16. Couldn't get it to play on my flickr page...


Posted by: S_Walker May 19 2011, 12:14 PM

Excellent Mike! BTW, how do you get an animated gif to play on flickr? Tried uploading one last night but it doesn't work. You can see my animation in the "looking ahead" thread, unless the mods decide it doesn't belong there (though I put it there as part of a question).

Posted by: djellison May 19 2011, 01:47 PM

You have to click the option to see it 'full size'

Posted by: S_Walker May 19 2011, 01:58 PM

QUOTE (djellison @ May 19 2011, 09:47 AM) *
You have to click the option to see it 'full size'

Doesn't work, at least on the two animated GIFs I loaded. I bet it's because I have a free account, rather than a "pro" account.

Posted by: elakdawalla May 19 2011, 02:29 PM

QUOTE (S_Walker @ May 19 2011, 03:32 AM) *
How would I find out the exact times certain images were recorded? For example, images W00067528.jpg and W00067533.jpg appear to have been recorded one Saturnian day apart. I'd like to measure the movement of features between the two images, so exact image times become important.

When the raws page was first launched, you could figure this out fairly easily because you could search on time as well as date. But they removed that capability at the request of the imaging team. So now the only way I know of to find out the time that an image was taken -- apart from asking an imaging team member very nicely -- is to use the http://pds-rings.seti.org/tools/viewer2_sat.html. I plug in the date of the image and 12:00 UTC and then nudge forward and backward in time until I can produce a view that matches the image. This is far easier for views of moons (or views of Saturn containing moons) than it is for Saturn images, because the moons move around so fast.

Posted by: elakdawalla May 19 2011, 02:31 PM

I think that's correct. A "pro" account doesn't cost very much though. The Amateur Space Images website that was supposed to launch in March (ahem. I know. It's in alpha right now, still working it) will allow you to upload and display animated gifs.

Posted by: S_Walker May 19 2011, 03:10 PM

QUOTE (elakdawalla @ May 19 2011, 10:31 AM) *
I think that's correct. A "pro" account doesn't cost very much though. The Amateur Space Images website that was supposed to launch in March (ahem. I know. It's in alpha right now, still working it) will allow you to upload and display animated gifs.


Thanks!

Posted by: JohnVV May 19 2011, 11:11 PM

QUOTE
How would I find out the exact times certain images were recorded? For example, images W00067528.jpg and W00067533.jpg appear to have been recorded one Saturnian day apart. I'd like to measure the movement of features between the two images, so exact image times become important.

to add to the very good answer above

once the images are on PDS in the label (.lbl) then the time is listed down to the thousandth of a sec.
example :N1637461416_1.LBL N1637461416_1.CUB
http://www.imagebam.com/image/d80f1d133019152
IMAGE_TIME = 2009-325T01:40:25.491

Posted by: ugordan May 23 2011, 11:14 AM

Oh my... ohmy.gif

http://saturn.jpl.nasa.gov/photos/raw/rawimagedetails/index.cfm?imageID=237664
http://saturn.jpl.nasa.gov/photos/raw/rawimagedetails/index.cfm?imageID=237672
http://saturn.jpl.nasa.gov/photos/raw/rawimagedetails/index.cfm?imageID=237675

Posted by: Poolio May 23 2011, 12:01 PM

Wow, those are some of the most striking images we've seen yet.

Posted by: Decepticon May 23 2011, 04:29 PM

Someone Please Color that!

Thats my new Desktop smile.gif

Posted by: dilo May 23 2011, 05:42 PM

QUOTE (Decepticon @ May 23 2011, 04:29 PM) *
Someone Please Color that!

Attempt with RGB combination N00171682+3+4 (with motion compensation):

 

Posted by: dilo May 23 2011, 06:33 PM

In a similar attempt on Titan+Saturn I wasn't able to reach good colors, so I made a hand-colorization of N0017167 with enhanced contrast and removed hot-pixel:


I hope is worth a wallpaper... rolleyes.gif

Posted by: Decepticon May 23 2011, 07:09 PM

Excellent!

Posted by: kyokugaisha May 23 2011, 10:07 PM

Quick composite colourisation of N00171681 using N00171684/3/2 and a little unsharp mask.


Posted by: kyokugaisha May 23 2011, 10:41 PM

And the same for N00171680 using N00171680/79/78.


Posted by: ngunn May 23 2011, 10:58 PM

What an entrance - those are really good. Thanks!

Posted by: kyokugaisha May 23 2011, 11:10 PM

No probs! Everyone is normally so quick on here.

Here is the last one using N00171692/1/0 over N00171689. This was a bit harder as I've tried to keep Saturn's unlit side in the background thus leaving some compression artifacts.


Posted by: ngunn May 23 2011, 11:16 PM

Brilliant again! A good call keeping Saturn visible - I really like what you're doing. You'll have more fans in the morning.

Posted by: machi May 24 2011, 12:44 AM

Very nice kodak moments and beautiful processed images rolleyes.gif .
But I think, that famous image with Enceladus' geysers, Titan and rings is still unbeaten cool.gif .

Posted by: elakdawalla May 24 2011, 03:15 AM

Speaking of which, that data is now public (part of the last PDS release) and is much better in that format than the raw JPEG format, but no one has yet stepped forward to redo that awesome group effort version of the image....

Posted by: S_Walker May 24 2011, 12:16 PM

My attempt at Tethys, Titan, and ring-lit Saturn.


Posted by: elakdawalla May 24 2011, 07:49 PM

Moved several posts discussing the use of IMG2PNG to convert/calibrate Cassini images into the http://www.unmannedspaceflight.com/index.php?showtopic=4979.

Posted by: Ian R May 27 2011, 11:52 AM

My attempt at producing a stacked, up-sampled, Titan-only and colour-corrected composite:


Posted by: john_s May 27 2011, 09:20 PM

Gorgeous images! It seems kinda churlish to point out that they are all are upside down, with north at the bottom...

John

Posted by: S_Walker May 27 2011, 10:01 PM

QUOTE (john_s @ May 27 2011, 05:20 PM) *
Gorgeous images! It seems kinda churlish to point out that they are all are upside down, with north at the bottom...

John


It's customary for planetary imagers to depict images south up because until the mid-70's, everyone observing the planets used newtonian reflectors.

Posted by: ugordan May 27 2011, 10:22 PM

Then the next logical question comes to mind - why haven't we been doing that for the first 4 years of Cassini's mission...

Posted by: john_s May 27 2011, 11:56 PM

For those who aren't familiar with the conventions, amateur astronomers often display telescopic planetary images with south at the top, to approximate the view through the eyepiece of many telescopes (for observers in the Earth's northern hemisphere). Professional astronomers, and planetary scientists (professional and amateur) working with spacecraft images, usually put north at the top unless there's a good reason not to do so. Personally, I'd like to see the amateur astronomers change their convention, in this digital age, so we can all look at the solar system the same way...

John

Posted by: Ian R May 30 2011, 11:09 AM

Here's a (north up) version, with Dione just peeking out behind Titan:


Posted by: stevesliva May 31 2011, 02:34 AM

QUOTE (john_s @ May 27 2011, 07:56 PM) *
For those who aren't familiar with the conventions, amateur astronomers often display telescopic planetary images with south at the top, to approximate the view through the eyepiece of many telescopes (for observers in the Earth's northern hemisphere). Professional astronomers, and planetary scientists (professional and amateur) working with spacecraft images, usually put north at the top unless there's a good reason not to do so.


I'd wondered why that was, when the storm on Saturn and the impact on Jupiter made it apparent. Makes sense. Maybe we'll use the metric system and the British will drive on the correct side of the road soon, too.

Posted by: AndyG May 31 2011, 08:47 AM

Oi! We do drive on the correct side of the road.

It, urrrmm, keeps our sword arms free. rolleyes.gif

Andy

Posted by: Stu May 31 2011, 09:21 AM

QUOTE (stevesliva @ May 31 2011, 03:34 AM) *
and the British will drive on the correct side of the road soon, too.


Oh, we do drive on the right side... the side that lets us have a good view of the dragons, Red London buses and CorBlimeyMaryPoppins! chimmernee sweeps that are just everywhere... laugh.gif

Posted by: S_Walker May 31 2011, 11:57 AM

QUOTE (john_s @ May 27 2011, 07:56 PM) *
For those who aren't familiar with the conventions, amateur astronomers often display telescopic planetary images with south at the top, to approximate the view through the eyepiece of many telescopes (for observers in the Earth's northern hemisphere). Professional astronomers, and planetary scientists (professional and amateur) working with spacecraft images, usually put north at the top unless there's a good reason not to do so. Personally, I'd like to see the amateur astronomers change their convention, in this digital age, so we can all look at the solar system the same way...

John


It's not a big deal, really. After all, there is no "up" in space...

Posted by: NGC3314 May 31 2011, 01:24 PM

QUOTE (S_Walker @ May 31 2011, 05:57 AM) *
It's not a big deal, really. After all, there is no "up" in space...


Most folks here may not be old enough to recall that there were once two conventions for east and west on the Moon's surface - the astronomical convention corresponded to which limb faced which horizon (matching celestial east and west). That yielded to the astronautical convention, matching the terrestrial sense, about the time it appeared people might be going there and such agencies as the USAF got into the lunar cartography business. I suspect this switch saved more confusion that we can easily imagine. The switch was http://the-moon.wikispaces.com/IAU+Directions in 1961.

A quick Google check shows that, for example the 1953 Questar map reproduced on the telescope barrel labels the western limb on the side of Mare Crisium.

Posted by: john_s May 31 2011, 07:57 PM

And of course Mare Orientale is in the middle of the moon's western hemisphere...

Meanwhile, there are still two conflicting definitions of "North" on Pluto and other retrograde-spinning worlds, and for planetary satellites, scientists use west longitudes while engineers sometimes use east longitudes, so all is not yet harmonious.

John

Posted by: ilbasso Jun 1 2011, 05:39 PM

This was of course before Lunar Orbiter took pictures of the East and West Poles, laying the controversy to rest.

Posted by: S_Walker Jun 1 2011, 07:18 PM

I may be too young to remember the flipping of east/west for lunar coordinates, but am reminded of it every other month while editing our lunar columnist.
For planetary images, scientists prefer north up images, while all the planetary groups (BAA, ALPO, etc) require south up for the images.

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