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MOM At Mars, Mission Operations
Krit
post Sep 29 2014, 01:06 PM
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Another photo (from the ISRO Facebook Page)

"Regional dust storm activities over northern hemisphere of Mars - captured by Mars Color Camera on-board ISRO's Mars Orbiter Mission.
The image was taken from an altitude of 74500 km from the surface of Mars."


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vikingmars
post Sep 30 2014, 08:03 AM
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My interpretation, processed, de-noised and de-saturated...
Looks like the Red Planet people dreamed on in the 50's !
And CONGRATULATIONS again to India ! Enjoy... smile.gif
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Julius
post Sep 30 2014, 12:06 PM
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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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vikingmars
post Sep 30 2014, 12:34 PM
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Thanks Julius. But what is the "Ted's version", you are referring to, please ?
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Krit
post Sep 30 2014, 12:53 PM
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I suppose he is referring to this version.
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djellison
post Sep 30 2014, 01:28 PM
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QUOTE (Julius @ Sep 30 2014, 04:06 AM) *
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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Julius
post Sep 30 2014, 03:45 PM
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What about dust clouds resulting from a dust storm? Are they white in colour?
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djellison
post Sep 30 2014, 03:58 PM
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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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elakdawalla
post Sep 30 2014, 04:06 PM
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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


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Bjorn Jonsson
post Oct 1 2014, 12:51 AM
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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:

Attached Image


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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Bjorn Jonsson
post Oct 1 2014, 01:13 AM
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QUOTE (elakdawalla @ Sep 30 2014, 04:06 PM) *
Here's a roundup of links to processed versions I've seen -- have I missed any?

I also found versions by Don Davis and Mattias Malmer on Facebook.
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mcaplinger
post Oct 1 2014, 02:43 AM
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QUOTE (Bjorn Jonsson @ Sep 30 2014, 05:51 PM) *
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.


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Disclaimer: This post is based on public information only. Any opinions are my own.
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vikingmars
post Oct 1 2014, 07:38 AM
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QUOTE (elakdawalla @ Sep 30 2014, 06:06 PM) *
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 smile.gif
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Julius
post Oct 2 2014, 09:20 PM
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Only now I realize who vikingmars is! I have 'visions of mars' in my mars books collection..brilliant work!
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wildespace
post Oct 6 2014, 07:22 AM
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A quick Photoshop levels adjustment, using "Enhance Per Channel Contrast" with "Snap Neutral Midtones" box checked:

Attached Image


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.


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