Jezero Delta Campaign, Sols 414-1000, 21 Apr 2022- 23 Dec 2023 |
Jezero Delta Campaign, Sols 414-1000, 21 Apr 2022- 23 Dec 2023 |
Apr 21 2022, 07:21 PM
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#16
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Member Group: Members Posts: 362 Joined: 13-April 06 From: Malta Member No.: 741 |
Think we can kick off the new phase of exploration at Jezero.
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Apr 30 2022, 08:40 PM
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#17
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Member Group: Members Posts: 680 Joined: 9-May 21 From: Germany Member No.: 9017 |
Tau : any clue as to what minerals the colors represent? Sorry, no clue. The colors are somewhat arbitrary, because the results of the principal components analysis depent on the overall image content and some manual adjustments. Irrespective of this, radiometrically calibrated multispectral image data are required for mineral determination. An idea of the calibration and processing pipeline is given by this paper, this paper, and this document. With radiometrically calibrated data and mineral spectra libraries, it might be possible, see the "Mineralogy" chapter and Fig. 3 in this paper. The rover has further instruments for elemental and mineral analysis (SuperCam, SHERLOC). |
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Apr 30 2022, 09:11 PM
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#18
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Member Group: Members Posts: 234 Joined: 14-January 22 Member No.: 9140 |
I think with PCA, all that you can safely say about two highly contrasting colors is that there is a difference between two things, but there's no definite information about the nature of that difference, and it could easily be some combination of illumination, texture, composition or possibly other things, in any unknown combination.
For example, when you see the color patterns where oil or gasoline and water are on wet pavement, the color differences have absolutely nothing to do with compositional differences. An image of snow and ice might show considerable variation in color even though every bit of solid present is pure H2O. Moreover, with the PCA, the contrasts seen across one part of the image are further altered by what happens to be present in other parts of the image. We may easily be looking at one more or less constant composition of the rocks in these photos with different history of weathering, burial, dust cover, etc. |
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