[X] My Assistant

[Guest_AlexBlackwell_*]

I guess it's never too early.

Titan-14 Science Highlights

Ultraviolet Imaging Spectrometer (UVIS) – will probe haze optical properties, atmospheric nitrogen emissions and hydrocarbon absorption, and absorption by methane of the Lyman-alpha interplanetary background which helps us understand the distribution of methane in the thermosphere of Titan.

Radio Science Subsystem (RSS) - A T14 ingress/egress occultation of Titan will provide high spatial-resolution electron number density profile of the ionosphere, temperature-pressure and absorption profiles of the neutral atmosphere , as well as information about the small-scale structure of the atmosphere (gravity waves, turbulence, layers). An inbound and outbound RSS bistatic scattering observations of Titan's surface will provide information about the dielectric constant, nature, and roughness of the region probed.

Composite Infrared Spectrometer (CIRS) - will perform high spectral resolution studies of Titan's limb in the far-infrared regime unseen by Voyager, to search for new species and to map the vertical distribution of CO, CH4, HCN and H2O. CIRS will also continue existing campaigns of global temperature and composition mapping, extending spatial and temporal coverage.

Radio and Plasma Wave Spectrometer (RPWS) – Study the interaction of the magnetosphere with Titan at intermediate distances for evidence of ion pickup, radio emissions, density profiles, and the general wave environment.

[volcanopele]

At the rate you are going Alex, you will posting the T44 preview in a couple of weeks

[Guest_AlexBlackwell_*]

At the rate you are going Alex, you will posting the T44 preview in a couple of weeks

Oh, I'll let T44 clear Aftermarket first

[Big_Gazza]

I thought T14 was going to include a SAR pass? Starting in southern Shangri-La, and heading east skirting southern Belet before dipping down and fizzing out before reaching Tsegihi.

Is this still the plan? I'm a certifiable SAR-junkie craving for a hit, so I certainly hope so

[Guest_AlexBlackwell_*]

I thought T14 was going to include a SAR pass? Starting in southern Shangri-La, and heading east skirting southern Belet before dipping down and fizzing out before reaching Tsegihi.

Is this still the plan? I'm a certifiable SAR-junkie craving for a hit, so I certainly hope so

Cassini RADAR team member Ralph Lorenz put it best during the T11-T14 TOST Preview meeting: "T14 - nothing."

[volcanopele]

T14 is a bistatic pass, not a RADAR SAR pass. I think the tracks shown on the Cassini Cam page include both RADAR SAR and Bistatic passes and don't differentiate between the two.

For SAR junkies, the next SAR pass will take place on July 22 for T16. This pass comes very close to the north pole (swath reaches as far north as ~80N). All the passes from T16 through T19 have SAR. T17 (Sept. 7) is a half-SAR pass (only the time after, or before can't remember which, C/A has SAR), and covers western Fensal and northeast Xanadu. T18 (Sept. 23) is another half swath at north polar latitudes reaching as far north as ~67N. Finally, T19 (Oct. 9) will be another North polar pass (reaching as far north as 82N), overlapping the T16 swath in some areas.

[Guest_BruceMoomaw_*]

Well, bistatic radar is not to be sneezed at in understanding the place.

[The Messenger]

Well, bistatic radar is not to be sneezed at in understanding the place.

http://www.aas.org/publications/baas/v32n3/dps2000/121.htm

Bistatic-scattering is a well-established technique for determination of the nature and physical properties of planets and their satellites...Information regarding surface properties is recovered from analysis of the received echo intensity, polarization, and spectral properties. In particular, echo polarization over the Brewster-angle-range of icy surfaces (50-65 deg.) yields direct estimates of the (composite) surface dielectric constant independent of surface roughness (if surface scattering is dominant). Observations over a range of scattering angles yield additional diagnostic information regarding the nature of the scattering mechanism and related physical surface properties (liquid vs. solid, surface vs. volume, surface roughness, …etc).

After a few of these passes, we should have a much better idea about how wet the sand is

[Decepticon]

Does this Bistatic-scattering create a image?

[Guest_BruceMoomaw_*]

I would imagine that -- if they point the spacecraft's radar dish in an appropriate way -- analysis of the echoes of the radar pulses received on Earth for signal strength, timing and Doppler dispersion could allow us to break them down into at least a low-resolution imaging map, in just the same way that the spacecraft itself does so when it recieves its own radar echoes. Bistatic radar was used a number of times on Magellan, but I don't know how good the spatial resolution of the resultant echoes was.)

[Phil Stooke]

Some Venus bistatic data have been presented as maps... it's a long time since I looked at it, but I think it was Venera data - probably the earlier Venera orbiters - and in Cosmic Research or some such place. The coordinates given were hard to interpret, I seem to recall (E or W? N or S?). They only covered very small areas.

Phil

[edstrick]

The first bistatic planetary radar observations, I believe, were by Mariner 6 and/or 7! A plot of the received spectrum of the signal as the spacecraft were going into (I think, don't know about exiting without digging in the "stacks" for a probable xerox of a paper in Icarus) occultation, shows the carrier frequency of the signal and a doppler shifted weak reflected signal that converged with the direct signal and disappeared at occultation. Viking orbiters did a few experimental bistatic passes too.

I believe plots exist of bistatic signals from the Pioneer Venus probes bouncing off the surface before impact. Not much signal, lots of noise, but "kewl"

[Thorsten]

T14 Flyby page is up!

http://saturn.jpl.nasa.gov/multimedia/prod...description.pdf

[Decepticon]

I'm looking forward to seeing images of Elba Facula.

When ESO took images of this part of titan it has always struck me as being a massive crater/basin. Since then there really doesnt seem to be much evidence for that.

Here's the image I'm am talking about.

[volcanopele]

I'm looking forward to seeing images of Elba Facula.

When ESO took images of this part of titan it has always struck me as being a massive crater/basin. Since then there really doesnt seem to be much evidence for that.

Here's the image I'm am talking about.

Our best imaging of Elba Facula came in T11.