Juramike
Feb 13 2008, 12:03 PM
MarcF
Feb 13 2008, 03:35 PM
I didn't know that it was possible to change the viewing side during SAR scanning !!
Really great idea !! We will get a SAR view of Hotei and a nice resolution of the Huygens landing site.
I'm expecting some surprises.
Marc.
ngunn
Feb 14 2008, 10:58 AM
QUOTE (Juramike @ Feb 13 2008, 12:03 PM)
LPSC abstract provides an exciting preview:
Indeed it does. I'm really hoping that some more of the highland valley networks and lowland 'flood moraines' in the Huygens images will be resolved. With the recent VIMS close-up data (also eagerly anticipated) this flyby should wrap up Cassini's landing site imaging campaign. I expect a comprehensive synthesis of these results will be undertaken at this point.
rlorenz
Feb 14 2008, 03:21 PM
QUOTE (MarcF @ Feb 13 2008, 10:35 AM)
I didn't know that it was possible to change the viewing side during SAR scanning !!
Really great idea !!
It is nice to have the flexibility to do that, but you do lose a minute or two of imaging
during the turn (there is some data but degraded)
nprev
Feb 14 2008, 03:30 PM
QUOTE (rlorenz @ Feb 14 2008, 07:21 AM)
...you do lose a minute or two of imaging
during the turn (there is some data but degraded)
I figured that. Just out of curiosity, can the incident angle be changed sufficiently (and rapidly enough) to reimage the same area and hopefully produce a 3D composite, or is the relative velocity too great?
Juramike
Feb 14 2008, 11:00 PM
I'm really hoping that the "spooky dude" formation gets resolved, and that other similar "spooky dude" formations are also observed in other channels.
I've got a pet theory that the "spooky dude" formation and most of the channel was emplaced gouged during a huge earlier flood event going from E to W, followed afterwords by smaller flood event(s) going from W to E. I think that reversible channels (not tidal) might be common on Titan.
(The spooky dudes parabolic shapes point the wrong way for them to have been emplaced during a W to E flood. Also, the tops are nice and bright in DISR, indicating they were high and dry during the last flood and didn't get the "organic paint" washed off.)
If this is correct, other nearby channels may show similar patterns and parabolic shapes going from E to W.
(I'm assuming the spooky dude formation is a RADAR-brighter cobble pile and will be slightly brighter when observed by RADAR compared to muddy ice sands. There were a few bright pixels in the T8 Swath that might've been a hint of the spooky dude formation.)
And I'm really, really, really hoping that the Cassini RADAR Team makes this swath available to the public really quickly, like they did for the South Polar Dec 20th Swath.
-Mike
volcanopele
Feb 14 2008, 11:14 PM
Rev59 Looking Ahead article is now online:
http://ciclops.org/view.php?id=4788
Juramike
Feb 14 2008, 11:28 PM
From looking ahead: "The second half of the RADAR swath will also cover a part of far southeastern Adiri, seen by ISS as an interesting patchwork of bright and dark material."
I strongly suspect that Adiri is made of tectonic ridges going EW but with broader undulations that run N-S. When the two are combined, you get the cool-o checkerboard pattern seen in SE Adiri. (In the T8 RADAR Swath you can see that some sections of the long EW ridges have a thinner ice sand mantle. They have been partially buried by dune sands and darker smoother organic-ice muds.) The bright dark checkerboard pattern is also seen by ISS.
A different look angle might get some great 3D information that might confirm this.
-Mike
rlorenz
Feb 17 2008, 10:24 PM
QUOTE (nprev @ Feb 14 2008, 10:30 AM)
I figured that. Just out of curiosity, can the incident angle be changed sufficiently (and rapidly enough) to reimage the same area and hopefully produce a 3D composite, or is the relative velocity too great?
Not sure what you mean here by 3D composite- this sounds like spotlighting (dwelling on the same spot)
which beats down the speckle noise by getting more looks, but of course then you lose
areal coverage. We've done a little bit of spotlighting with HiSAR, but not near closest approach
as spotlighting then would sacrifice good coverage
nprev
Feb 17 2008, 11:28 PM
Ralph, I was basically asking if Cassini can take a look at the same area during the same pass maybe a minute apart for stereo imaging. This spotlighting techniques sounds like what I meant, and understand that some coverage would have to be sacrificed; probably not worth doing often, since there's a lot of first-look radar mapping yet to be done.
ugordan
Feb 18 2008, 05:41 PM
Excuse me for stealing the thread here a bit, but there's one thing puzzling me (English not being my first language):
Click to view attachmentI was always under the impression the construct
Huygen's means belonging/related to something/someone named
Huygen so in this case it would be wrong to spell it that way, rather
Huygens' seems correct. I thought the former was a common spelling error with names ending with 's' in the english language, but I'm seeing it more and more lately and it makes me wonder - is that valid spelling?
dvandorn
Feb 18 2008, 05:47 PM
Ugordan -- you're right, they're wrong.
-the other Doug
nprev
Feb 18 2008, 05:57 PM
Good eye, Gordan; incorrect usage of the possessive apostrophe is
extremely common among native English-speakers in the US.
BTW, if you never told anyone that English wasn't your first language, nobody would ever know; you are incredibly fluent!
centsworth_II
Feb 18 2008, 05:58 PM
I think the correct form would be "Huygens" with no apostrophe
at all. "The Huygens landing site" is using Huygens as a name
for the site. If the phrase were "Cassini searches Titan for Huygens'
landing site," -- without "the" before Huygens -- then Huygens'
would be correct.
ugordan
Feb 18 2008, 06:01 PM
That makes sense, centsworth_II. No apostrophe in this case sounds right.
Well, back to our regular program schedule now.
dvandorn
Feb 18 2008, 07:08 PM
A very simple way to check if you're using the right construction is to replace the noun that naturally ends with an 's' with a noun that doesn't. In this case, let's replace it with the noun 'Viking' (another planetary lander), and the result:
"the Viking's landing site"
does read poorly. In this case, obviously, you don't need a possessive at all. It all hinges on the use of the definite article -- without the 'the,' you would use a possessive form.
-the other Doug
rlorenz
Feb 19 2008, 07:53 AM
QUOTE (centsworth_II @ Feb 18 2008, 12:58 PM)
I think the correct form would be "Huygens" with no apostrophe
at all. "The Huygens landing site" is using Huygens as a name
for the site.
Yeah, I've seen (US) people who really should know better write
Huygen's more often than I'd expect.
Of course, you could dodge the issue and say 'Hubert Curien Memorial Station'
Or not.
belleraphon1
Feb 19 2008, 11:46 PM
ngunn
Feb 21 2008, 04:53 PM
I notice the offending apostrophe has been removed. I wonder if you helped, Gordan?
All squeezed into the back seat now for tomorrow's flyby.
edstrick
Feb 23 2008, 10:31 AM
Has any data been posted to the raw images brouser fur maybe 5 days?... I don't think the current LARGE batch of B-ring dark side monitoring images (I think that's what they are) have changed for that long.
volcanopele
Feb 23 2008, 05:36 PM
Yeah, they are having issues again. Not sure why. We have gotten images since those B-ring images.
Sunspot
Feb 24 2008, 04:41 PM
QUOTE (volcanopele @ Feb 23 2008, 05:36 PM)
Yeah, they are having issues again. Not sure why. We have gotten images since those B-ring images.
Hmmm...it's been like it for 12 days now, are they aware it's not updating?
Juramike
Feb 27 2008, 07:30 AM
It looks like some raw images from the Titan encounters might be up, but I'm not able to see any of the images or read the files.
Anyone else having this problem?
Doc
Feb 27 2008, 07:44 AM
QUOTE (Juramike @ Feb 27 2008, 10:30 AM)
It looks like some raw images from the Titan encounters might be up, but I'm not able to see any of the images or read the files.
Anyone else having this problem?
I too am having a problem. The images dont appear at all.
What the heck is going on?!
Juramike
Feb 27 2008, 10:24 PM
New images are up!!!
Here's a nice image of the Ciclops-dude of Belet:
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00103240.jpg(Adiri to the East)
-Mike
Some of the closer images seem a bit "fuzzier" than normal, maybe due to the filter set used?
Lots of clouds over Titan..?
Click to view attachmentOriginal image found
here...
ugordan
Mar 2 2008, 10:23 AM
I'm only seeing one obvious cloud, the streaky one up in the north. The brighter region south of the equator is I believe a terrain feature (possibly something seasonal), see
this thread for example. Take note that the obvious clouds (the south pole one and a hint of a north polar cloud) have a different color than the brighter terrain in both types of multispectral composites.
Matt
Mar 4 2008, 07:00 PM
A new radar image appeared about an hour ago, showing radar bright channels on Hotei Arcus, but now it's vanished!
Hopefully it will be back again soon.
volcanopele
Mar 4 2008, 07:08 PM
Yeah, it is not up at the moment, but to give you an idea:
http://photojournal.jpl.nasa.gov/catalog/PIA02568Ducks and runs...
ugordan
Mar 4 2008, 07:15 PM
QUOTE (volcanopele @ Mar 4 2008, 08:08 PM)
Yeah, it is not up at the moment, but to give you an idea:
LOL at the coincidence. That imagery was taken on Feb 22, 2000, exactly 8 years before the "missing" RADAR image.
Time flies, doesn't it?
Webscientist
Mar 5 2008, 09:48 AM
I've also seen the latest radar image of Hotei Arcus with these radar bright channels.
When I take a look at Hotei Arcus in VIMS images, I have the impression it is the outcome of a meteoritic impact. I assume that the bright staff has been ejected to the east. I see a steep slope on the west part of the assumed irregular crater and a more progressive slope to the east probably because the meteor came from the west or north west.
I propose three hypothesis for the nature of the bright channels or grooves:
first: the pseudo channels are a consequence of methane (...) rain.
Second: the pseudo channels have been carved by some materials resulting from the impact.
Third: the pseudo channels are pseudo lava tubes, in other words channels througout which a liquid like carbon dioxide or liquid water have run.
Of course, I don't see in a crystal ball. So It is only a point of view. It could also be a cryovolcanic phenomenon...
Matt
Mar 5 2008, 06:43 PM
bright channels seemed to flow away from bright rugged terrain in the south down to darker, lower terrain, but it I thought it looked as though their might have been two different types of deposit; younger, darker deposits overlaying older, slightly brighter (rougher?) deposits. I only saw the image briefly and at it's lowest resolution though....so I may have completely misinterpretad it.
Matt
Mar 5 2008, 06:51 PM
I think I'd go for a combination of 1 and 2 regarding your propositions
But would really like to see the image again at higher res
titanicrivers
Apr 25 2008, 01:58 AM
Has anyone seen the T41 SAR hi res image posted in a public forum. It was mentioned in abstracts and presentations in Feb and March conferences but I've yet to see it except on global map in one of Emily's Planetary Society blogs from 2 weeks ago. I was curious about the consensus on what Hotei Arcus proved to be! (that 'smile' reminded me of an old impact basin partially filled in or eroded away.
ngunn
Apr 25 2008, 07:56 AM
A lot of people (including me) are very keen to see this swath in particular. I think the release of SAR images is having to wait for a revised assessment of Titan's rotation state to establish a more secure system of geographical coordinates. I don't know if this affects the processing of the images themselves or just delays their publication.
titanicrivers
May 11 2008, 06:17 AM
I wonder if the SAR crew are awaiting the T-43 flyby data so as to make a stereo composite of Hotei Arcus to enhance its identity via a topography mapping. Would make a nice short paper.
titanicrivers
Jul 21 2008, 06:05 PM
Came accross this poster abstract from a recent Planetary Science meeting:
P23A-04
Titan's Surface Geology from the Cassini RADAR
* Lopes, R M (rosaly.m.lopes@jpl.nasa.gov), Jet Propulsion Laboratory, Caltech, Pasadena, CA 91109, United States et. al.
With respect to Hotei Arcus:
"The T41 flyby, which took place in February 2008, obtained SAR coverage of the Hotei Arcus region, which has been suggested as cryovolcanic and possibly currently active [Nelson et al., submitted to Icarus]. SAR images obtained to date show that cryovolcanism is not ubiquitous on Titan, and that some features interpreted as cryovolcanic, such as Ganesa Macula appear to be old and modified by other processes. The flows in the Hotei Arcus region appear well-preserved and are younger than surrounding terrains, implying that cryovolcanic activity may have occurred relatively recently. Mapping of geological units from SAR data is revealing the distribution and relative ages of geological materials which, in turn, helps us to understand the evolution of Titan's surface."
Has anyone seen the images that would have accompanied this presentation?!
Other interesting abstracts from that meeting (some on Titan) are at www.esa.int/esaMI/Cassini-Huygens/SEMLMXLVGJE
Juramike
Jul 21 2008, 06:23 PM
Good catch, titanicrivers!
[A quick Google search turns up that P23-A04 is also a portion of the gene sequence of the malaria genome. That link might come in handy someday.]Here is the link to the Titan abstract.
A few other quotes plucked from the abstract (emphasis in bold mine):
"
Channels and drainage features appear common at all latitudes, indicating that erosion by liquids has been a major modification process."
"
cryovolcanism is not ubiquitous on Titan"
Hopefully the Nelson et al. paper cruises through peer review. Definitely something to look forward to...
(Maybe they'll release the T41 RADAR Swath soon after?)
-Mike
[Ha! Looks like titanicrivers beat me to clipping out the abstract! Post modified so as to not be redundant with titanicrivers' post above]
titanicrivers
Jul 21 2008, 10:05 PM
QUOTE (Juramike @ Jul 21 2008, 01:23 PM)
Good catch, titanicrivers!
[Ha! Looks like titanicrivers beat me to clipping out the abstract! Post modified so as to not be redundant with titanicrivers' post above]
Lol ! Sometimes these little Eureka-moments can make one's day! Can imagine how exciting the raw data is to the primary investigators when they receive it from Cassini!
remcook
Jul 22 2008, 10:02 AM
I think the Nelson et al. paper refers to analysis of VIMS cubes, showing apparent changes of brightness at hotei arcus. He seems to be promoting this idea for quite some time already. see:
http://adsabs.harvard.edu/abs/2007AGUFM.P22B..03Nhttp://adsabs.harvard.edu/abs/2007LPI....38.2158Nhttp://adsabs.harvard.edu/abs/2006AGUFM.P12A..06Nhttp://adsabs.harvard.edu/abs/2006DPS....38.5209Nhttp://adsabs.harvard.edu/abs/2006epsc.conf..404Nhttp://adsabs.harvard.edu/abs/2006cosp...36.2128Nhttp://adsabs.harvard.edu/abs/2005DPS....37.4612NMust be hard to get through the review process.
I assume the reason for the late release (and quick pulling on the website) of the SAR data of Hotei Arcus is that they are trying to get it in Science/Nature.
titanicrivers
Oct 14 2008, 04:08 AM
[quote name='ngunn' date='Apr 25 2008, 01:56 AM' post='112814']
A lot of people (including me) are very keen to see this swath in particular.
R. Lopes and colleagues have presented their findings at DPS 2008 concerning Hotei Arcus. An enhanced T41 radar image of Hotei Arcus appears below. It is worth logging into her slide presentation given earlier today. Link to all the talks here:
http://dps08.astro.cornell.edu/AAS_WebcastSchedule_2008.html .Her presentation is in: Session 34: Titan: Subsurface:
http://cornellmediasite.cit.cornell.edu/me...c7-17e07b541bdbHer presentation starts at slide 75. To get there quickly click on "text slide list" and scroll down to slide 75 and click on "slide 75 00:23:42"
Click to view attachment
ngunn
Oct 14 2008, 08:04 AM
That was interesting indeed, but I note that the Huygens landing site is still under wraps.
ngunn
Dec 19 2008, 01:12 PM
Thanks to Bjorn for this:
http://www.unmannedspaceflight.com/index.p...ic=5697&hl=Does this mean we now have the SAR covering the Huygens landing site?
peter59
Jan 6 2009, 07:04 PM
Huygens Landing Site and Hotei Arcus.
Click to view attachmentEnjoy !
volcanopele
Jan 6 2009, 07:16 PM
Looks like that is only the Huygens landing site area, don't see Hotei Arcus in there.
Juramike's favorite sliced carrot is at right in that view.
Juramike
Jan 6 2009, 08:03 PM
...and the part that would show whether or not there was a central rise at the centroid of the sliced carrot feature is...just....out..of..view.....
arrrgh!
Any chance this will arrive on VP's RADAR Swath page soon?
volcanopele
Jan 6 2009, 08:30 PM
Alright, alright, I'm on it
volcanopele
Jan 6 2009, 10:36 PM
I've added the three swaths from T41 to my RADAR swath page, as well as the T30 swath that finally showed up on the PDS a couple of months ago:
http://pirlwww.lpl.arizona.edu/~perry/RADAR/
Juramike
Jan 6 2009, 10:52 PM
Wow! Thank you!
That T41 Hotei Arcus portion is just totally enigmatic. I'm having a hard time seeing exactly how it aligns with the ISS images.
ngunn
Jan 6 2009, 11:33 PM
A SAR feast indeed! Long awaited and much appreciated. As usual I cannot trust my objectivity when peering at these images, especially the Huygens area, so I look forward to someone doing a proper job of correlation with the Huygens DISR panorama. I think the 'spooky dude' can be discerned.
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