Difference between revisions of "October 25, 2009"
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<em>image by [mailto:revans_01420@yahoo.com Rick Evans]</em><br /> | <em>image by [mailto:revans_01420@yahoo.com Rick Evans]</em><br /> | ||
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| − | I created this image of [http://www.lpod.org | + | I created this image of [http://www.lpod.org/archive/2004/03/LPOD-2004-03-02.htm Mons Hansteen], a lunar [http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1975LPICo.234..189W&amp;data_type=PDF_HIGH&amp;whole_paper=YES&amp;type=PRINTER&amp;filetype=.pdf red spot], by performing principal component image analysis (PCA) on the five Clementine UVVIS multispectral band images (i.e. 415, 750, 900, 950 and 1000 nm). PCA is a tool sometimes used in multispectral geology [http://rst.gsfc.nasa.gov/Sect5/Sect5_3.html studies] to reveal variations in mineral composition. Using <em>Photoshop</em> the Clementine images were loaded respectively into five alpha channels of a color image with the R, G and B channels deleted. With all alpha channels selected, [http://reindeergraphics.com/index.php?option=com_content&task=view&id=24&Itemid=47 FoveaPro 4.0] software was used to create a PCA transform and then to transform the alpha channel images into their respective principal component images. The first three resulting PCA images were then loaded respectively into the R, G and B channels of a color image producing the final image shown above. Mons Hansteen and all other lunar red spot features show up with a very distinctive reddish hue in such images. Lunar red spots seem to absorb preferentially in the ultraviolet region of the spectrum compared to the visible; other lunar mafic features including the central peaks of Tycho are fascinating to observe with this technique as well. <br /> |
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<em>[mailto:revans_01420@yahoo.com Rick Evans]</em><br /> | <em>[mailto:revans_01420@yahoo.com Rick Evans]</em><br /> | ||
Revision as of 17:19, 22 March 2015
Red Arrowhead
image by Rick Evans
I created this image of Mons Hansteen, a lunar red spot, by performing principal component image analysis (PCA) on the five Clementine UVVIS multispectral band images (i.e. 415, 750, 900, 950 and 1000 nm). PCA is a tool sometimes used in multispectral geology studies to reveal variations in mineral composition. Using Photoshop the Clementine images were loaded respectively into five alpha channels of a color image with the R, G and B channels deleted. With all alpha channels selected, FoveaPro 4.0 software was used to create a PCA transform and then to transform the alpha channel images into their respective principal component images. The first three resulting PCA images were then loaded respectively into the R, G and B channels of a color image producing the final image shown above. Mons Hansteen and all other lunar red spot features show up with a very distinctive reddish hue in such images. Lunar red spots seem to absorb preferentially in the ultraviolet region of the spectrum compared to the visible; other lunar mafic features including the central peaks of Tycho are fascinating to observe with this technique as well.
Rick Evans
Lunar History Note: Today is the 184th birthday of perhaps the greatest selenographer of the 19th century -J.F. Julius Schmidt (1825-1884). Thanks to Mark Tillotson for the reminder!
Related Links
Rükl plate 40
Yesterday's LPOD: Das Mystery
Tomorrow's LPOD: Wonder Rille
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