Want to know what areas Cassini will be observing in future passes? The solar system simulator now allows you to see through Titan's clouds

http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1

Sorry, I didn't notice this thread before Alan, but perhaps you will comment on my observation that the SSS has the wrong face of Titan as the Saturn-facing hemisphere.

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If you agree, can this be remedied?

[quote name='alan' date='May 9 2009, 07:19 PM' post='140164']
Want to know what areas Cassini will be observing in future passes? The solar system simulator now allows you to see through Titan's clouds

Here's the actual view of Titan from Cassini on May 10th (click on image below) showing that SSS's view is incorrect regarding the Titan surface actually illuminated (i.e. Adiri is actually in darkness in the Cassini photo). The Celestia grid view shows the correct orientation and visible surface of Titan for the Cassini photo.

Oops

How far are they off, is it 180 degrees or some intermediate value.

It almost seems like its 180 degrees, as if the wrong hemisphere was originally designated the Saturn-facing hemisphere. This equinox period during which many raw images of Titan were taken, dated and posted on the Cassini web site should be a good time to align your otherwise beautiful graphic of Titan with the raw image surface photos, much like I have done for the Celestia program Titan images shown above. There are probably more precise ways to do this but aligning the images with different sets of photos taken weeks apart might be a sensitive way to check both the rotational and orbital motions of Titan. One might look at the Ciclops web site for the different Titan encounters for the last 5 visits or so and the mission description which has views of Titan from Cassini usually 2 hrs before and 2 hours after a close encounter.

Comparing the SSS with Cassini from Aug. 25, 2009. SSS set to show Titan from Cassini on Aug 25, 2009 @ 21:25 UTC. Both SSS and Cassini wide angle camera image are from about 172.3 k Km (click on image below). Celestia grids help to quantitate the differences between the actual view from the spacecraft (right panels) and the SSS projected views (left panels). SSS shows the opposite hemisphere close to 180 degrees away and seems to have the view with north up rather than leaving it as a raw image from the camera-spacecraft perspective. Hopefully corrections to the SSS Titan surface rendering program module can be made to closely match such Cassini images and saved so that other time epochs will be rendered more accurately.

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The SSS appears back on line ! (for the Messenger Mercury flyby I believe). Unfortunately it still appears to have Titan with an about-face error and wrong hemsphere facing Saturn. Perhaps that can be attended to after the Mercury flyby.

Just doing a reality check ... hmmm it appears the Solar System Simulator program still has Titan 180 degrees out of sync and oriented with N straight up.

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(Apologies for this reminder, but a fix would be welcome!)

Checking the SSS again. Using the more precise Celestia grid and the Cassini image of Titan (N00149278)from 12/30/2009. Again the SSS shows the opposite Titan face. The center longitude is 80W for the SSS and 260W for the actual image. This more accurate measurement confirms the SSS image is off by 180 degrees longitude, showing the opposite hemisphere. Hopefully this can be easily remedied.
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<Hint> The feedback link for Solar System Simulator is at the bottom its page. </Hint>

Thanks Alan. I had originally sent a note to David Seal at NASA before posting in the SSS thread but did not get a reply and so I thought you might be involved in the programming and might facilitate a correction. I will send another comment to David Seal.
Bob

hi a question are you using volcanopele's add on with his spice kernels ?
this is what i get
Titan as seen from earth today at UTC 12:00
jpl sss
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celestia - eye balled
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Hey guys this problem with the SSS is fixed now. Titan has corrected its orientation.

How nice of it to indulge us

Which reminds me, I need to post an update to that with brand new kernels...

just a list posted over at shatters would do it .

Wow the SSS for Titan is fixed !!!
Its a great app and resource now!
Many thanks.
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SSS we have a problem . . .
The Solar System Simulator program has developed a glitch: when the Cassini spacecraft is entered the program has a crash landing!!!
Here's a typical error message :http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=-82&vbody=1001&month=8&day=12&year=2010&hour=00&minute=00&fovmul=1&rfov=60&bfov=30&porbs=1&showsc=1
I've gotten this on 4 different computers. Anyone have the same experience or know of a workaround?

titanicriversthat is a normal "500 internal server error "

they are down
try again tomorrow .

Cassini, or any of the Saturnian objects on the SSS is down, the rest seems to work. My wild guess is they ran out of trajectory data on one of those objects (possibly Cassini). From memory, the old (pre-XXM) long-term trajectory files for Cassini ended around a month after the end of the extended mission, so that may be it.

According to the SSS, there have been some nice line-ups of the planets as seen from Mars lately. Perhaps Earth, Venus and Jupiter are bright enough to see in the Martian twilight sky at whatever latitude has the ecliptic most perpendicular to the horizon.

(Sorry, but Saturn is on the other side of the sky from Mars. I didn't notice that this was under the Saturn folder! Perhaps this will entertain you until the SSS gets Saturn back?)

bob

Yahoo! The Solar System Simulator for Cassini and Titan has been repaired. I used it to make a nice composite for the most recent CL1 CB3 images from August 17th showing an apparent cloud near Sotra Facula.

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