T28 (April 10th 2007) Options

[belleraphon1]

Titan T28 mission description is now available. Note grountracks displayed on pp 9-10.
http://saturn.jpl.nasa.gov/multimedia/prod...description.pdf

[ugordan]

These groundtrack graphs are awesome, I hope they keep them in the future.

[ngunn]

The groundtracks polar plot on page 10 includes the first version I've seen of the ISS Titan Map in polar format. In our lakes discussions here I mentioned that the South polar one in particular would be very useful for comparisons between the two polar regions.

On Ciclops Sector 6 I posted a query about whether such a projection could be made available but received no reply.

Now this appears in the Mission Description, indicating that such a polar version does indeed exist somewhere. Does anybody here have access to it in its original, non-PDS, unannotated form?

[ugordan]

The south polar coverage on that ground track map looks the same as Ta south polar coverage to me, with the clouds artificially removed. Then there's this release showing Ontario Lacus and I believe it's a polar view with the red mark marking the south pole. I'm not aware of any other polar views.

[ngunn]

Thanks ugordan. Yes I know that view, though I didn't know it was an actual polar projection. However it's nice at last to see the whole hemisphere with the lat and long grid. It gives a clearer idea of the relative positions of Ontario Lacus, Mezzoramia and the other features. They must have a hi-res version somewhere, so why not release it?

[ugordan]

As I said, I believe that polar view from the groundtrack plot was just using the updated Titan map which was projected onto a globe and then this was produced. The updated map IIRC uses the Ta data (it's not terribly up-to-date for other regions as well) for the south pole which if memory serves me is a pretty low resolution view (300 000 km C/A) so releasing a separate polar view of it would be of little use.

On the other hand, yes, it would have been nice if that Ontario Lacus mosaic clearly stated it's a polar projection and also a version with a lat/long grid would have been nice.

[ngunn]

Sure, I realise that the map uses mostly lower res and not fully up-to-date data and that the images themselves are a better place to go for whatever details are available. I'm not expecting to see any new details in a polar version, I just like having the geographical context made explicit. It helps with formulating questions like why is Ontario Lacus (probably) wet and southern Mezzoramia (probably) dry? It would also be useful for plotting future RADAR noodles - and other planned imagery - on, now that there is heightened interest in the high latitudes.

[belleraphon1]

All...

I feel the pain too and would like to see better projections but there really has not been much south pole coverage in any detail as yet in the mission.

looking at http://cassinicam.com/titanflybys/ by Joe Knapp looks like some better coverage of the south pole (and some of my other faveorite regions) is coming up later this year (In addition to more north polar passes in this quarter).


Jul 19 07 (T34) - Belet

Oct 02 07 (T36) - South Pole

Nov 19 07 (T37) - Xanadu

Dec 05 07 (T38) - South Pole

Dec 20 07 (T39) - South Pole

Jan 05 08 (T40) - Xanadu

According to Emily's site http://planetary.org/explore/topics/saturn/titan_radar.html
T39 will have south pole SAR coverage.

Good stuff is coming .....

Craig

[volcanopele]

The latest "Looking Ahead" post on the CICLOPS site for Rev42 and T28 is online:

http://ciclops.org/view.php?id=2901

[belleraphon1]

Thanks volcanopele.....

from the latest "Looking Ahead"

"Cassini encounters Titan for the 29th time on April 10, with a closest approach distance of only 990 km (615 mi). Like the last few encounters with Titan, this flyby (known as T28) will allow for imaging of the northern portion of Titan’s trailing hemisphere following closest approach. The Cassini cameras will take two mosaics of this region. These mosaics (and a lower resolution context mosaic) focus on an area centered at 45º North Latitude, 240º West Longitude, north of the dark region named Belet. The T28 observations will allow for a follow-up on discoveries made in T25, T26, and T27 images, such as a set of lineaments north of Belet … features which were also observed by the RADAR instrument during T21 (December 12, 2006). The discovery of northern mid-latitude clouds in late February suggests that these observations may also allow for cloud tracking. During closest approach, the Cassini RADAR instrument will obtain a Synthetic Aperture Radar (SAR) swath covering similar terrain as the swath obtained in February, during the T25 encounter (see PIA09182). This RADAR swath will cover, like the T25 swath, the northern portion of a Caspian Sea-sized dark region discovered by ISS in February. Shortly after closest approach, VIMS will obtain several high-resolution observations of the northern half of the trailing hemisphere, including the dark lineaments mentioned above. "

Very Cool!!!!! RADAR saw the lineaments on T21!

And clouds at mid-northern latitudes.... seasons are a changin!?

Craig

I do not

[ngunn]

T28 raw images up now.

[remcook]

This seems much more up close than previously. Lots of weirdness on the surface there (crater? http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107207 ) of which this is my favourite I think:

http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107204

You couldn't see this area very well from the last flyby, not these lattitude stripes anyway I think. Dune fields cutting into somthing else??? Very cool anyway

tiger stripes?/rivers?/weirdness:
http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107189
http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107185

Anyone got a needle?

[JRehling]

Anyone got a needle?

The dunes (which have never looked so clear in ISS images that I can recall) should be going east-west, so north is either to the left or to the right. (I know, that sounds like the kind of directions you'd get in New England.)

[remcook]

in the ciclops page VP linked it's the area in the middle I think ( shaped like a ">") so these stripes look to go along lines of latitude.

the needle was a stitching reference, not so much a compass reference

[ugordan]

Err, what dunes? Are you referring to precise vertical dark strips? Those are artifacts from the camera, enhanced by binning and histogram stretch. These kinds of artifacts are present in practically all telemetry modes of the cameras and as of the time the calibration volumes were archived in the PDS, their cause was unknown.