MOM At Mars, Mission Operations |
MOM At Mars, Mission Operations |
Sep 29 2014, 01:06 PM
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#16
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Newbie Group: Members Posts: 3 Joined: 30-January 14 Member No.: 7116 |
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Sep 30 2014, 08:03 AM
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#17
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Senior Member Group: Members Posts: 1089 Joined: 19-February 05 From: Close to Meudon Observatory in France Member No.: 172 |
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Sep 30 2014, 12:06 PM
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#18
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Member Group: Members Posts: 362 Joined: 13-April 06 From: Malta Member No.: 741 |
I'm no expert in image processing but I would think this version of red colour seems more real cos I don't believe the dust clouds to the upper left would be that white as depicted in Ted 's version.
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Sep 30 2014, 12:34 PM
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#19
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Senior Member Group: Members Posts: 1089 Joined: 19-February 05 From: Close to Meudon Observatory in France Member No.: 172 |
Thanks Julius. But what is the "Ted's version", you are referring to, please ?
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Sep 30 2014, 12:53 PM
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#20
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Newbie Group: Members Posts: 3 Joined: 30-January 14 Member No.: 7116 |
I suppose he is referring to this version.
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Sep 30 2014, 01:28 PM
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#21
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
I'm no expert in image processing but I would think this version of red colour seems more real cos I don't believe the dust clouds to the upper left would be that white as depicted in Ted 's version. Check out imagery from Hubble, or the Rosetta OSIRIS flyby imagery - white clouds are the norm. MEX has seen white fog, MGS MOC/WA saw white clouds. The MRO MARCI weather updates regularly show a sluice of white clouds around Mars. Even amateur ground based astronomers have seen white clouds on Mars. I've seen them thru a tiny telescope with my own eyes. |
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Sep 30 2014, 03:45 PM
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#22
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Member Group: Members Posts: 362 Joined: 13-April 06 From: Malta Member No.: 741 |
What about dust clouds resulting from a dust storm? Are they white in colour?
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Sep 30 2014, 03:58 PM
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#23
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
Obviously not - which is why the dust storms visible in every version of this I've seen retain their ochre / butterscotch color.
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Sep 30 2014, 04:06 PM
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#24
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
It's been interesting to see all the different takes on this photo. People seem to agree that the original was too red and saturated, but the corrections have been varied. Here's a roundup of links to processed versions I've seen -- have I missed any?
Original Ted Stryk Olivier de Goursac Judy Schmidt Fred Calef - with place names Elisabetta Bonora & Marco Faccin -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Oct 1 2014, 12:51 AM
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#25
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IMG to PNG GOD Group: Moderator Posts: 2254 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
Beautiful images so far and congratulations to the Indians. Clearly this mission is going to be the best source ever of global color views of Mars, maybe a bit like a 'super VMC'. Hopefully a 'PDS-like' version of the images will be released in the future to make more accurate processing of these images possible for us here.
The various versions of this image are interesting. Here is a quick-and-dirty version I did by reducing the color saturation a bit. I then corrected the color using Mars' global spectrum as a guide, together with what Mars has looked like to me through a telescope. Planetary color is highly subjective so I really don't know which one of the various versions posted here is the most realistic one. But I agree that the original image is probably too saturated and reddish and probably the blue channel should be brighter, at least in the dark areas (it's remarkably close to 0 in the darkest regions). Here is my version: The terminator is a bit ugly at lower left. This is a processing artifact; I may do a better version later. |
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Oct 1 2014, 01:13 AM
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#26
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IMG to PNG GOD Group: Moderator Posts: 2254 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
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Oct 1 2014, 02:43 AM
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#27
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
Hopefully a 'PDS-like' version of the images will be released in the future to make more accurate processing of these images possible for us here. From http://www.hou.usra.edu/meetings/lpsc2014/pdf/2449.pdf "MARS COLOR CAMERA ONBOARD MARS ORBITER MISSION: SCIENTIFIC OBJECTIVES & EARTH IMAGING RESULTS", A.S. Arya et al: QUOTE Data Product Schema : An MCC image is a Bayer filter mosaic, a color filter array (CFA) for arranging RGB color filters on a square grid of photo sensors. The demosaicing algorithm is employed to reconstruct a full color image. Level-1 product (calibrated data) generation involves detector wise photo response non-uniformity model correction as understood from pre launch laboratory calibration exercises; line/pixel loss correction and tagging the geographic coordinates to each pixel. Level-1, corrected are generated for users. The software
pipeline produces calibrated data to generate minimum Planetary Data System (PDS) compliance product. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Oct 1 2014, 07:38 AM
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#28
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Senior Member Group: Members Posts: 1089 Joined: 19-February 05 From: Close to Meudon Observatory in France Member No.: 172 |
It's been interesting to see all the different takes on this photo. People seem to agree that the original was too red and saturated, but the corrections have been varied. Thanks Emily for this interesting compilation. The somewhat "yellowish" (not pure white) color I found after my processings for the dust clouds on the northern hemisphere is consistent with MARCI team's Mars weather reports : "Regional storm activity picked up in the northern hemisphere, with large storms occurring from Utopia to Arcadia and arcuate-shaped storms following the Acidalia storm track into Chryse"... And in the southern hemisphere, ice crystal clouds appear white indeed. Also, Mars is not a "bright" planet. Thus, I believe my interpretation is a close representation to what the human eyes would see |
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Oct 2 2014, 09:20 PM
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#29
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Member Group: Members Posts: 362 Joined: 13-April 06 From: Malta Member No.: 741 |
Only now I realize who vikingmars is! I have 'visions of mars' in my mars books collection..brilliant work!
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Oct 6 2014, 07:22 AM
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#30
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Member Group: Members Posts: 238 Joined: 15-January 13 Member No.: 6842 |
A quick Photoshop levels adjustment, using "Enhance Per Channel Contrast" with "Snap Neutral Midtones" box checked:
I think this has resulted in colours very close to the colours of the surface as we have seen from raw Mastcam and MAHLI images. I remember reading in a few places that the pronouncedly red appearance of Mars when photographed from outside of its atmoshere is due to all the dust suspended in its atmosphere. -------------------- Curiosity rover panoramas: http://www.facebook.com/CuriosityRoverPanoramas
My Photosynth panoramas: http://photosynth.net/userprofilepage.aspx...;content=Synths |
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