Rev 015 Sept 23-26, 2005, Calypso-Tethys-Hyperion Options

[Decepticon]

Should be a good one. Less than 2 weeks away.

[Decepticon]

Tethys just before closest approach. http://space.jpl.nasa.gov/cgi-bin/wspace?t...porbs=1&brite=1

Hyperion Just before closest approach. http://space.jpl.nasa.gov/cgi-bin/wspace?t...porbs=1&brite=1

[Decepticon]

Update: From tedstryk Thred.

09/23/2005 15 Distant Flyby (altitude = 91,000 km; 57,000 mi) of moon Calypso
09/23/2005 15 Distant Flyby (altitude = 70,000 km; 43,000 mi) of moon Mimas
09/23/2005 15 Distant Flyby (altitude = 98,000 km; 61,000 mi) of moon Prometheus
09/24/2005 15 Close Flyby (altitude = 1,500 km; 900 mi) of moon Tethys
09/26/2005 15 Close Flyby (altitude = 500 km; 300 mi) of moon Hyperion

[volcanopele]

Update: From tedstryk Thred.

hmm, didn't know about the Prometheus and Mimas encounters...

[tedstryk]

I really hope that they take advantage of Mimas flyby if it will cover regions not covered in the last flyby and is almost as close. The Tethys coverage looks spectacular!

[volcanopele]

Wow, that was released already?!?

That should provide some great views of Ithaca Chasma. I should note that the 150 m/pixel colored square near the center of the map, that covers portions of the center part of Ithaca Chasma, probably doesn't exist. The software we use to create these maps for some reason creates thinks our movement of the boresight to the center of the disk at the start or end of an observation is a frame, which in this case it isn't. I've learned how to get rid of those, so hopefully they won't show up in the T8 map.

[tedstryk]

I have been working on a Tethys related issue during the last few days. There is one sliver of the Voyager highres mosaic that was not lost in the scan platform problem. However, they couldn't locate it, because due to the problem, they weren't sure how the camera was pointed. Although the image, at 2.2 km/pixel, is not all that great by Cassini standards, I was still curious about the mystery. I have reprocessed it using the faux-super resolution technique I used on the Galileo Amalthea image. I then tried to locate features on Steve Albers' map. I think some of the features clearly match up, and while some seem missing on Steve's map, that may be due to the fact that this is still by far the best image of this area and the other images for the region are so poor. It will be right on the limb for Cassini when it is close, so part of it will be covered in a very forshortened way - not sure about all of it. Do you all think I have identified it correctly. Here is its location at a feature match-up.



Also, here is the image by itself, without lines on it.

[um3k]

Ted, try rotating the Voyager image 90 degrees counterclockwise. Then, look near the north pole on the map. This image may be helpful: http://www.solarviews.com/cap/sat/tethys.htm
Also this, showing the image sequence: http://www.planetary.org/saturn/tethys.html
It may also be helpful to change to map to a polar projection.
Good luck.

[tedstryk]

Ted, try rotating the Voyager image 90 degrees counterclockwise. Then, look near the north pole on the map. This image may be helpful: http://www.solarviews.com/cap/sat/tethys.htm
Also this, showing the image sequence: http://www.planetary.org/saturn/tethys.html
It may also be helpful to change to map to a polar projection.
Good luck.

That is the original angle (90 degrees counter clockwise). But the features don't match anything polar. I have studied the image that is next closes you suggest, but it doesn't seem to fit up there. The problem is that there is no accurate orientation data. But it clearly seems to match this place on the map. The next best image on both of those links are from the same single frame, and it certainly doesn't "nest" in it at its original orientation.

[Decepticon]

Wow, that was released already?!?

I have yet to unerstand why they release them So late in the first place.

Maybe its a good sign.

[tedstryk]

I have yet to unerstand why they release them So late in the first place.

Maybe its a good sign.

My understanding is that they release them, and then they have to filter through a bunch of beaurocratic press office type places before they appear.

This technique (referring to the faux-super resolution technique I was speaking of in my earlier post - sorry - I switched gears without warning!) really does help with enlarging images. Here is a voyager image of
Janus using the same methodology
While with a single image it doesn't actually improve resolution, it makes the resolved features look sharper and less pixelated.

[Decepticon]

Once again, WOW!

[tfisher]

My understanding is that they release them, and then they have to filter through a bunch of beaurocratic press office type places before they appear.

This technique really does help with enlarging images.  Here is a voyager image of
Janus using the same methodology.  While with a single image it doesn't actually improve resolution, it makes the resolved features look sharper and less pixelated.

I had never before heard of bureaucratic press offices being used as a filter for image processing. But apparantly it works quite well, judging by the your results. That's a quite nice Janus image.

[edstrick]

Tedstryk: ..."There is one sliver of the Voyager highres mosaic that was not lost in the scan platform problem."...

Historical note. Some of the lost Voyager imagery including the Tethys hirez mosaic was *NOT* lost due to the scan platform problem. As Voyager was approaching the ring plane crossing, it did another of the regular roll maneuvers which variously optimized magnetosphere studies by pointing fields of view of charge particle detectors and plasma wave antennas, and also optimized sky-accessibility for scan-platform instruments. They came out of a roll maneuver with about a 1 degree roll offset from the desired attitude. I don't recall if it was gyro-drift problems <maybe due to radiation> or "operator" error. As a result, the scan platform narrow angle camera, with a 1/2 or 1/3 degree field of view (can't remember), neatly mosaiced a patch of sky next to Tethys. They were also not on the rings during ring plane crossing. They got WA ringplane data, not NA.

Shortly AFTER this, the scan platform stuck during a high-rate slew and the excrement hit the fan.

[tedstryk]

.  As a result, the scan platform narrow angle camera, with a 1/2 or 1/3 degree field of view (can't remember), neatly mosaiced a patch of sky next to Tethys. 

This solves a mystery that has long bothered me: Given the distance from Tethys, it seemed the odds that it would have even gotten a sliver with a stuck platform were somewhere between slim and none.