TY - JOUR
T1 - Principal components analysis of Mars in the near-infrared
AU - Klassen, David R.
N1 - Funding Information:
Much of the data was acquired by, or in concert with, Jim Bell so I thank him for these data and the help with the reduction, initial analyses, and discussions of results. I also thank the telescope operators, day crew, and support staff of the NASA IRTF, without whom the observations could not have been made. I am especially indebted to Bill Golisch, Dave Griep, and Charlie Kaminski for their many years of help with the acquisition of Mars spectral images from the IRTF. I also thank Cornell students Richard Zentko and Scott Southard for assistance with the data analysis software. Mars cylindrical mapping and some stellar photometry were performed with the help of Rowan students Bill Peppard, Ted Scabarozi, Brian Fanslau, and Thomas Wark. Much thanks to Michael Wolff and his DISORT “boot camp” and Michael D. Smith & David A. Glenar through the NASA-ASEE fellowship program for their help with atmospheric modeling. I also thank the two anonymous reviewers for their helpful commentary and suggestions. This work was supported by grants from the NASA Planetary Astronomy, NSF-RUI, and NASA Planetary Geology Programs.
PY - 2009/11
Y1 - 2009/11
N2 - Principal components analysis and target transformation are applied to near-infrared image cubes of Mars in a study to disentangle the spectra into a small number of spectral endmembers and characterize the spectral information. The image cubes are ground-based telescopic data from the NASA Infrared Telescope Facility during the 1995 and 1999 near-aphelion oppositions when ice clouds were plentiful [Clancy, R.T., Grossman, A.W., Wolff, M.J., James, P.B., Rudy, D.J., Billawala, Y.N., Sandor, B.J., Lee, S.W., Muhleman, D.O., 1996. Icarus 122, 36-62; Wolff, M.J., Clancy, R.T., Whitney, B.A., Christensen, P.R., Pearl, J.C., 1999b. In: The Fifth International Conference on Mars, July 19-24, 1999, Pasadena, CA, pp. 6173], and the 2003 near-perihelion opposition when ice clouds are generally limited to topographically high regions (volcano cap clouds) but airborne dust is more common [Martin, L.J., Zurek, R.W., 1993. J. Geophys. Res. 98 (E2), 3221-3246]. The heart of the technique is to transform the data into a vector space along the dimensions of greatest spectral variance and then choose endmembers based on these new "trait" dimensions. This is done through a target transformation technique, comparing linear combinations of the principal components to a mineral spectral library. In general Mars can be modeled, on the whole, with only three spectral endmembers which account for almost 99% of the data variance. This is similar to results in the thermal infrared with Mars Global Surveyor Thermal Emission Spectrometer data [Bandfield, J.L., Hamilton, V.E., Christensen, P.R., 2000. Science 287, 1626-1630]. The globally recovered surface endmembers can be used as inputs to radiative transfer modeling in order to measure ice abundance in martian clouds [Klassen, D.R., Bell III, J.F., 2002. Bull. Am. Astron. Soc. 34, 865] and a preliminary test of this technique is also presented.
AB - Principal components analysis and target transformation are applied to near-infrared image cubes of Mars in a study to disentangle the spectra into a small number of spectral endmembers and characterize the spectral information. The image cubes are ground-based telescopic data from the NASA Infrared Telescope Facility during the 1995 and 1999 near-aphelion oppositions when ice clouds were plentiful [Clancy, R.T., Grossman, A.W., Wolff, M.J., James, P.B., Rudy, D.J., Billawala, Y.N., Sandor, B.J., Lee, S.W., Muhleman, D.O., 1996. Icarus 122, 36-62; Wolff, M.J., Clancy, R.T., Whitney, B.A., Christensen, P.R., Pearl, J.C., 1999b. In: The Fifth International Conference on Mars, July 19-24, 1999, Pasadena, CA, pp. 6173], and the 2003 near-perihelion opposition when ice clouds are generally limited to topographically high regions (volcano cap clouds) but airborne dust is more common [Martin, L.J., Zurek, R.W., 1993. J. Geophys. Res. 98 (E2), 3221-3246]. The heart of the technique is to transform the data into a vector space along the dimensions of greatest spectral variance and then choose endmembers based on these new "trait" dimensions. This is done through a target transformation technique, comparing linear combinations of the principal components to a mineral spectral library. In general Mars can be modeled, on the whole, with only three spectral endmembers which account for almost 99% of the data variance. This is similar to results in the thermal infrared with Mars Global Surveyor Thermal Emission Spectrometer data [Bandfield, J.L., Hamilton, V.E., Christensen, P.R., 2000. Science 287, 1626-1630]. The globally recovered surface endmembers can be used as inputs to radiative transfer modeling in order to measure ice abundance in martian clouds [Klassen, D.R., Bell III, J.F., 2002. Bull. Am. Astron. Soc. 34, 865] and a preliminary test of this technique is also presented.
UR - https://www.scopus.com/pages/publications/70349758079
UR - https://www.scopus.com/pages/publications/70349758079#tab=citedBy
U2 - 10.1016/j.icarus.2009.03.041
DO - 10.1016/j.icarus.2009.03.041
M3 - Article
AN - SCOPUS:70349758079
SN - 0019-1035
VL - 204
SP - 32
EP - 47
JO - Icarus
JF - Icarus
IS - 1
ER -