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Posted by: alan Feb 7 2005, 11:22 PM

I wonder when we will see the rest of this SAR pass at full resolution
http://s04.imagehost.org/view.php?image=/1848/SAR-Ta-crop.jpg

Posted by: Decepticon Feb 7 2005, 11:23 PM

WOW! What is it? Radar map from Huygens?

Posted by: volcanopele Feb 7 2005, 11:50 PM

It's the Cassini RADAR SAR strip from Ta

Posted by: alan Feb 7 2005, 11:54 PM

Its the entire SAR (Synthetic Aperature Radar) pass from October at low resolution. So far I've seen less than half of it on the cassini site, just the prettiest parts I found it here http://www.lpi.usra.edu/meetings/lpsc2005/pdf/2294.pdf

Posted by: Decepticon Feb 8 2005, 01:38 AM

Whoa, I didn't realize there was more.

Posted by: Fred Feb 8 2005, 04:07 AM

It's also low res in that pdf file. Where can we see it at full resolution? There are large black areas in it-- lakes maybe? Why didn't they post the whole thing on the Cassini website?

Posted by: alan Feb 8 2005, 04:25 AM

The pdf was in a list of presentations for the Lunar and Planetary Science Conference from March 14-18, I suspose we will see a higher resolution version of it afterwards.

Posted by: Roby72 Feb 8 2005, 11:46 AM

Is it possible to use the SAR on other moons also ?

Roby72

Posted by: Decepticon Feb 8 2005, 01:42 PM

Enceladus would be a possible target?

Can it be used to look for subsurface lakes/oceans?

Posted by: pioneer Feb 8 2005, 05:17 PM

I think it already has. Wasn't it used on Phoebe before SOI and found ice below the dark surface?

Posted by: ngunn May 26 2006, 02:42 PM

A general query about SAR on future flybys. I note from Emily's blog that on some flybys the SAR may operate at 'less than optimal altitude'. I assume this means at greater altitude than optimal, and that the coverage strips will be wider at the expense of resolution. In view of the diversity of Titan's surface and highly variable degree to which radar and infra-red albedos correlate this may be no bad thing. I wonder if anyone has suggested doing some SAR from significantly higher altitudes deliberately just to get comparative albedos in radar and IR over a bigger sample of the terrain. Would this be possible with the instument?

I'm off on holiday now - hope for enlightenment on my return.

Posted by: Richard Trigaux May 26 2006, 06:36 PM

SAR on close Enceladus flyby would be fine, it could be powerful enough to somewhat penetrate the ice and show underground water ducts or pockets. But I don't know if this is possible:
-The instrument is not designed for such a short range, could it work?
-there is a problem with the orientation of Cassini, which would at the same time use the large gain antenna and the camera. Camera will pass first, of course.

Posted by: BruceMoomaw May 26 2006, 08:04 PM

They've just been using it for scatterometry and radiometry on the other icy moons, because those measurements can be made at a considerable distance, allowing time to re-orient the spacecraft to point its cameras and spectrometers at the moon during the closest part of the flyby. The SAR and altimetry can only be done at close range (I believe closer than 2000 km) -- meaning that if you use them on a moon, you have to sacrifice your visual imaging and spectral mapping, which simply isn't worthwhile for any moon whose surface you can see unobstructed by haze (especially given the small number of achievable close flybys of other moons).

Enceladus, as Richard suggests, just might be an exception if they make several more close passes -- SAR can penetrate (I believe) about 10 meters under the ice, which means that it might be able to locate near-surface water pockets. But this is a long-shot possibility for the extended mission.