[X] My Assistant

[ugordan]

I guess the news belongs to the Mars forum as well, but since I'm more of a Huygens guy myself, I figured this is a better place:

http://www.esa.int/esaCP/SEMA96ULWFE_index_0.html

[alan]

Does this mean the Nature articles are about to be released too?

[DDAVIS]

Does this mean the Nature articles are about to be released too?

Doggone well about time. I would like to see the final image mosaics from Huygens, with color overlays from the spectral data, as we saw in the test images.

Don

[ugordan]

I would like to see the final image mosaics from Huygens, with color overlays from the spectral data, as we saw in the test images.

I wouldn't hold my breath for color mosaics like that, they would need pretty accurate reconstruction of where the spectrometer was looking at (not that it samples only a single point, rather it averages the entire FOV, IMHO). In any case, the color resolution would probably turn out very low and the whole scene uniformly colored, sort of like that one uniformly hued surface image.
I seem to remember Marty Tomasko saying that most of the spectra they've taken is very similar.

[DDAVIS]

[quote=ugordan,Nov 22 2005, 03:23 PM]
I wouldn't hold my breath for color mosaics like that, they would need pretty accurate reconstruction of where the spectrometer was looking at (not that it samples only a single point, rather it averages the entire FOV, IMHO). In any case, the color resolution would probably turn out very low and the whole scene uniformly colored, sort of like that one uniformly hued surface image.


Perhaps, but this test image, at:

http://www.lpl.arizona.edu/~kholso/images/.../mosaic_c_3.jpg

shows some resolution of color information. In addition, the quality of the images in the tests seems to be suspiciously better than the performance of the flown camera. I suppose low contrast in the Titan view provided an opportunity for compression artifacts to have a field day.

Don

[ugordan]

  Perhaps, but this test image, at:

http://www.lpl.arizona.edu/~kholso/images/.../mosaic_c_3.jpg

shows some resolution of color information. In addition, the quality of the images in the tests seems to be suspiciously better than the performance of the flown camera. I suppose low contrast in the Titan view provided an opportunity for compression artifacts to have a field day.

Not to mention that 7 years of cosmic radiation damage to the CCD had also done its job. Also, the test images were taken from a low altitude and they (the team)were able to provide complete coverage of the area beneath by rotating the camera. Huygens' descent was pretty much chaotic tumbling...

[DDAVIS]

[quote=ugordan,Nov 22 2005, 04:54 PM]
Not to mention that 7 years of cosmic radiation damage to the CCD had also done its job.

Were those CCD cameras markedly more sensative to Cosmic Rays than those used in Cassini or Galileo? I might expect distinctive defects on each and every frame of the three Huygens cameras caused by 'hits' on the CCD.



Also, the test images were taken from a low altitude and they (the team)were able to provide complete coverage of the area beneath by rotating the camera. Huygens' descent was pretty much chaotic tumbling...


Certainly, and they lost half the pictures due to a screw-up, I am not talking about coverage so much as inherent quality of the returned images. If you look at the test image mosaic, at:

http://www.lpl.arizona.edu/~kholso/images/...00_big_merc.jpg

you can see the sky at top displaying nominal gradations of brightness, which along with the rest of the image reveals little visible compression artifacting. Was the compression ratio in the earthbound tests the same as that actually used during the mission?

Don