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Posted by: Decepticon Aug 6 2005, 03:35 PM

It's been a while since a Titan flyby, Exciement builds up once again!

Posted by: volcanopele Aug 6 2005, 05:23 PM

This is an all-CIRS pass so not much for ISS on T6 But not to worry, T7 is only a couple of weeks later, complete with a RADAR swath.

Posted by: tedstryk Aug 6 2005, 06:04 PM

I'll admit I am confused by this...I understand why at close range a CIRS pass would limit ISS highres mosaics, but during approach and with WA imagery, couldn't global imagery at least be obtained? Is this a data rate problem? My understanding was that the remote sensing instruments were boresighted. On another note, any nontargeteds of interest?

Posted by: Decepticon Aug 6 2005, 06:22 PM

Is CIRS So bad? Can surface detail be seen?

Posted by: remcook Aug 6 2005, 06:52 PM

CIRS cannot see the surface and spatial resolution is limited. But it is the prime instrument for atmospheric composition determination.

I think it's more a matter of politics: dividing the time so that every instrument has its share of good observations. But I'm sure there will be SOME ISS images. Right?

Posted by: Decepticon Aug 6 2005, 07:16 PM

Any would be great. VP can comfirm this I guess?

Posted by: volcanopele Aug 6 2005, 11:35 PM

We get some imaging on T6, as ride-alongs with CIRS. But it is pretty limited in coverage, though there are wacs, but I tend not to be excited about those.

Posted by: volcanopele Aug 18 2005, 09:10 PM

T6 preview now up:

http://volcanopele.blogspot.com/2005/08/titan-6-flyby-info.html

T6 pdf:

http://saturn.jpl.nasa.gov/multimedia/products/pdfs/T6_descr_050815_updating3_FINAL.pdf

Posted by: JRehling Aug 18 2005, 09:26 PM

Jason, will the ISS ridealong give us best-yet coverage of the broad region around the western portion of the H? For now, I'm as eager to see the global picture get sharpened from >10 km resolution to <3 km resolution as I am to see more subkilometer closeups. This geometry will let us "patch" a big fuzzy area of the map. I assume that wide angle snaps will do this if narrow angle snaps before the flyby don't; can you verify that?

We're getting close to time to start making the first decent Titan globes...

Posted by: volcanopele Aug 18 2005, 09:33 PM

There will be some 2-5 km WAC imaging, but I usually shun those, because of the lack of an MT1 filter on the wide-angle camera. Now T7 in September, THAT's the encounter I am looking forward too

Posted by: remcook Aug 19 2005, 08:36 AM

details, details! What's the main focus of T7? (there will be radar too, right?)

I'm looking forward to this flyby, although there's no time to actually analyse the data till after DPS. Especially some south pole limb observations could be very handy!

Posted by: JRehling Aug 19 2005, 05:48 PM

It looks from the T6 coverage map like the 2-5 km coverage will hit the areas I was craving for. I assume that will be MT1 with the WAC -- the resolution that is quoted would be a joke if it were with the clear filter.

Of the portions of Titan in daylight, we've still got about a third of it to go to get nice (< 3 km / pixel) coverage. Those multiple flybys hitting the same longitudes over and over sure hurt the drive towards completeness! (Unavoidable, I know, and nice for other reasons -- but they hurt when one's waiting for the map to be filled in!)

3 km / pixel will look nice on a 12" globe, making "pixels" of about 140 dpi, which is very nice, and of course many areas will be mapped even better. (Yes, that's a unit conversion that could kill MCO many times over.) When the first pass over the north pole takes place after equinox (it may be around autumn 2010 when that is possible), save a spot on your desk for a really high-quality Titan globe. Now we just need some broad VIMS data to slap a color overlay on the ISS base. And a non-garish interpretation of those colors...

Posted by: volcanopele Aug 19 2005, 05:53 PM

The WAC images will be in CB3 filter (those looking at the surface). The MT1 filter is not on the wide-angle camera and we need it to correct the photometry. So for mapping purposes, the wide-angle camera is useless (for me anyway).

Posted by: volcanopele Aug 19 2005, 06:03 PM

Same region as this time, but we have a long period of prime observations, allowing for a much nicer mosaic than in T4 and T5.

Posted by: JRehling Aug 19 2005, 06:13 PM

This is interesting to me. Do we really need same-time base images (in MT1) to correct the photometry? It seems to me the MT1 image would be pretty easily simulable for the most part. You get an awful lot of the variance just by assuming a Lambertian sphere (fuzzy that up to get the atmosphere reaching above the limb, although that is irrelevant for surface mapping anyway), and most of the rest of the MT1 comes from latitude-dependent brightness variation, without much longitudinal variation give or take the rare cloud, right? So couldn't you just generate a pseudo-MT1 image using a very bland cylindrical map with latitudinal variation only, and make a final product by "diff"ing the CB3 image from the pseudo-MT1?

Posted by: volcanopele Aug 19 2005, 07:13 PM

That is another way to do it, but we are not at that point. we need more information on the properties of the haze particles in order to do this correctly. Until then, we continue to use MT1 images.

Posted by: Decepticon Aug 21 2005, 11:51 PM

No Nt on this pass?

Posted by: JRehling Aug 22 2005, 06:09 PM

I'm away from any useful image-processing software, but it looks to me as though a couple of Aug 17 images, even in the clear filter, might have added best-yet coverage of the longitudes west of the Huygens landing site. See

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=47625

Anybody with Photoshop, 10 minutes, and a yearning for exploration want to check this out??

Posted by: volcanopele Aug 22 2005, 07:26 PM

Actually, that image shows Senyko-east Aztlan region, not very close to the Huygens landing site. That is just a little farther east than the area to be covered during this encounter.