Looking ahead article is up: http://ciclops.org/view/5795/Rev117

I think this will be the SAR pass that parallels T8 in Belet.

I think this will be the SAR pass that parallels T8 in Belet.
[/quote]

Sure looks that way based on Dr. Spilker's Presentation http://saturn.jpl.nasa.gov/files/20090728_...5yr_Spilker.pdf. (a modified page 21 of her presentation featuring T61 and T8 SAR is shown below); also noted is the reported origin for the April 2008 tropical storm. As there's some overlap of T8 and T61 and one is pre storm one might look for subtle fluvial changes in the lower mid-portions of the swaths. T8 swath can be viewed here http://www.planetary.org/explore/topics/sa...n_radar.html#t8

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Mission description now available: http://saturn.jpl.nasa.gov/files/20090825_...description.pdf

From TR's map above, it also looks like those two bright blobs of 'rotten terrain" off W Adiri will get stereo SAR coverage as well.
It will be interesting to see if they have any appreciable relief above the dunes as compared to the W edge of Adiri itself.

(My money is that they are pretty flat and low-lying....)

Image of the night side of Titan taken August 22, 2009. RGB composite channel-balanced and cosmic ray hits cleaned up:

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"From TR's map above, it also looks like those two bright blobs of 'rotten terrain" off W Adiri will get stereo SAR coverage as well."

Another interesting area that may get stereo SAR coverage is the geologically diverse area featured in image PIA 03568 (taken from the western portion of T8 SAR, as noted in the graphic below). This area has a channel with sapping-like branches and small 'lake-like' areas at each end and has been discussed by Mike previously in this forum. Unfortunately the resolution of T61 will not be as favorable as the channel will be at the extreme western end of the swath. The channel may have already had stereo coverage to an extent by the T 21 swath (although I've not seen that full swath published).
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[quote name='Juramike' date='Aug 24 2009, 07:49 PM' post='145177']
Image of the night side of Titan taken August 22, 2009. RGB composite channel-balanced and cosmic ray hits cleaned up:

Beautifully done Mike.
Reminds me of an annular eclipse of the sun just before (or after) mid eclipse.

I'l second that - a great image. The green tinge over one hemisphere only is interesting.

What's the cause of that green tinge? The filters used to make the image? Or is it real?

Probably me getting carried away with the green channel. I shoulda oughta used Planetary Photojournal image PIA11468 as a reference to balance the colors.

Comparison view: http://photojournal.jpl.nasa.gov/catalog/PIA11468

The stereogrammetry of the T8-T21 overlap was released as PIA11829. The channel can be seen at the far left (and yep, it looks relatively deep).

Thanks Mike. And yes I didn't dig deep enough for Jason Perry's site has the complete T21 swath: http://pirlwww.lpl.arizona.edu/~perry/RADAR/ The portion of T21 with the channel is shown below, rotated and enhanced slightly. T8 obviously had the higher resolution coverage.
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FWIW, it looks to me like a channel registration issue. It's not trivially easy to align 3 filters on something as fuzzy as Titan's limb.

Oh sure, blame the victim.

- Jason

For these things, I boost the brightness off all three color channels until I can clearly see the detached haze layer, then align the three layers based on that layer. Then I use the regularly stretched versions, align them with the corresponding channel image, then merge.

Me too, VP, but the problem with raws is that haze layer is often lost in the compression artifacts.

Here's my alignment:
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This has just gotta be some weird combination of optical and compression artifacts, but it looks funky:
http://saturn.jpl.nasa.gov/multimedia/imag...3/W00059352.jpg

Pretty much optical effects only - dust rings, scattered light and internal reflections. Reminds me of one of the earliest Titan flybys in the mission, same kind of observations but this was farther out.

Yes! I noticed that one too. It's a nice piece of artwork indeed. Maybe we should have a go at thinking of captions. Here's one:

The real strange world and a couple of empty bottles

T61 provided another great opportunity to look at Titan through the filtered eyes of Cassini's wide angle camera (WAC). The sequence below shows a Celestia grid view of the Titan hemisphere that was sequentially imaged by WAC using a CL2 CB3 filter for surface features, an MT3 CL2 filter for zonal features of the lower stratospheric haze and finally a CL1 VIO filter which typically emphasizes the detached haze and north polar hood atmospheric structures.
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Nice animation, TR!

Anyone know how this compares to past combinations? Are we starting to see any seasonal shifts?

I've been looking back at WAC images using the MT3 filter from 2004 and they appear similar to the most recent one from T61 at first glance. The northern hemisphere is brighter (greater stratospheric haze particulates?). A north polar hood is seen on most VIO and UV filter images from 2004-2009. Looking at Voyager 2 images from 1981 one sees a 'brighter' southern hemisphere with a darker north polar hood but the images are taken throught different filters and so I'm not sure brighter has the same significance as brighter in Cassini's MT3 filter. Images from each of these time periods appear in the graphic below.

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Keep in mind that the bright/dark asymmetry differs depending on whether you are looking in the infrared or the UV/visible. The Voyager image has a shorter wavelength, so areas with more haze absorb more light (like the northern hemisphere) while areas with with less haze reflect more light and are brighter. You can see that in the violet filter image from the T61 wide-angle image set: http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=200184 In the IR, particularly in methane band filters, like with the MT3 image you point to, this pattern is reversed, the northern hemisphere is brighter.

The north-south asymmetry is probably caused by a difference in particle concentration, not particle size. In the infrared methane bands (like the MT3) the haze is scattering sunlight, while methane is absorbing. More haze will then show up brighter. In the blue/UV, the haze is actually more absorbing than scattering and darker than the Rayleigh scattering atmosphere. More haze will then show up darker. (see one of many of Ralph's papers on this)

Thank you VP and remcook for the enlightment and education!!! If I understand then it would be more appropriate to compare the Voyager image with the Cassini CL1 VIO image. Doing this suggests the stratospheric haze appearance now is very similar to that of 1981 when Voyager visited. This makes sense given Saturn's 29.6 year orbit and so Voyager's visit (28-29 years ago) found Saturn (and Titan) approximately the same season as now. The image below depicts all this.

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Some additional images of Titan following T61 flyby show the effects of the various filters on the stratospheric haze layers. The very cool Cassini-Huygens spacecraft was created by Gordon Morrison (copyright ©2006-2009). If one was to show Cassini in its current state, the Huygens probe would not be attached and there would be some gold foil covering up part of the spacecraft.

I think it is possible to use the more commonly acquired filtered images to create a "Methan-o-vision" version for Titan (like Aquavision uses the IR2, IR4, and WV channels with a complex channel mix).

Here is the idea and a possible translation (meaning-wise: H2O is to Earth as CH4 is to Titan) between the different channels in Aquavision and Methan-o-vision:

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Here's the Methan-o-vision image of Titan from the T61 flyby images:

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Funky combination of CL1 CB3, CL1 BL1, and inverted MT3 CL2 with a funky channel mix.
(Leveling and contrast enhancement of filtered images prior to loading into the channels).

Dull aqua-white is methane in the southern regions (not diminished by haze)

Yellow-orange are surface features: bright terrain and sand seas

Dark red brown is the polar hood, rich in haze products.

-Mike

T61 RADAR swath.
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... and T61 Inbound SAR-Low Imaging

PRODUCT_ID = "BIBQH08S158_D203_T061S03_V02"
MAP_RESOLUTION = 128.0<PIX/DEG>
MAP_SCALE = 0.35111116<KM/PIX>
MAXIMUM_LATITUDE = 17.65234839<DEG>
MINIMUM_LATITUDE = -32.15522020<DEG>
EASTERNMOST_LONGITUDE = 133.28073514<DEG>
WESTERNMOST_LONGITUDE = 182.68330998<DEG>
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PRODUCT_ID = "BIBQH04S159_D203_T061S04_V02"
MAP_RESOLUTION = 128.0<PIX/DEG>
MAP_SCALE = 0.35111116<KM/PIX>
MAXIMUM_LATITUDE = 24.87025192<DEG>
MINIMUM_LATITUDE = -32.15522020<DEG>
EASTERNMOST_LONGITUDE = 134.13051656<DEG>
WESTERNMOST_LONGITUDE = 185.61758703<DEG>
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PRODUCT_ID = "BIBQF07S158_D203_T061S02_V02"
MAP_RESOLUTION = 32.0000000<PIX/DEG>
MAP_SCALE = 1.4044446<KM/PIX>
MAXIMUM_LATITUDE = 17.6523484<DEG>
MINIMUM_LATITUDE = -32.1552202<DEG>
EASTERNMOST_LONGITUDE = 133.2807351<DEG>
WESTERNMOST_LONGITUDE = 182.6833100<DEG>
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Shouldn't that be HiSAR?

<ducks>

and
PRODUCT_ID = "BIBQH01N303_D203_T061S06_V02"
MAP_RESOLUTION = 128.0<PIX/DEG>
MAP_SCALE = 0.35111116<KM/PIX>
MAXIMUM_LATITUDE = 12.23214946<DEG>
MINIMUM_LATITUDE = -9.62625315<DEG>
EASTERNMOST_LONGITUDE = 293.93021440<DEG>
WESTERNMOST_LONGITUDE = 312.37412317<DEG>
Click to view attachment

What is this? weird