Regularization of Mars Reconnaissance Orbiter CRISM along‐track oversampled hyperspectral imaging observations of Mars
Abstract
Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) hyperspectral image data have been acquired in an along-track oversampled (ATO) mode with the intent of processing the data to better than the nominal ∼18 m/pixel ground resolution. We have implemented an iterative maximum log-likelihood method (MLM) that utilizes the instrument spectral and spatial transfer functions and includes a penalty function to regularize the data. Products are produced both in sensor space and as projected hyperspectral image cubes at 12 m/pixel. Preprocessing steps include retrieval of surface single scattering albedos (SSA) using the Hapke Function and DISORT-based radiative modeling of atmospheric gases and aerosols. Resultant SSA cubes are despiked to remove extrema and tested to ensure that the remaining data are Poisson-distributed, an underlying assumption for the MLM algorithm implementation. Two examples of processed ATO data sets are presented. ATO0002EC79 covers the route taken by the Curiosity rover during its initial ascent of Mount Sharp in Gale Crater. SSA data are used to model mineral abundances and grain sizes predicted to be present in the Namib barchan sand dune sampled and analyzed by Curiosity. CRISM based results compare favorably to in situ results derived from Curiosity's measurement campaign. ATO0002DDF9 covers Marathon Valley on the Cape Tribulation rim segment of Endeavour Crater. SSA spectra indicate the presence of a minor component of Fe^(3+) and Mg^(2+) smectites on the valley floor and walls. Localization to 12 m/pixel provided the detailed spatial information needed for the Opportunity rover to traverse to and characterize those outcrops that have the deepest absorptions. The combination of orbital and rover-based data show that the smectite-bearing outcrops in Marathon Valley are impact breccias that are basaltic in composition and that have been isochemically altered in a low water to rock environment.
Additional Information
© 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Available online 23 September 2016. This work was supported in part from NASA through Contract 110609 from The Johns Hopkins University/Applied Physics Laboratory for participation in the CRISM Science Team, Cornell University Subaward 77301–10534 for participation in the Opportunity rover mission, and Contract 110609 from The California Institute Technology/Jet Propulsion Laboratory for participation in the Curiosity rover mission. We thank K. Li for optimization of the MLM code and A. A. Fraeman for early work on regularization. Many thanks to Valerie Fox, Kathryn Powell, and Susan Slavney for comments on the manuscript. Data analysis made use of ENVI (Exelis Visual Information Solutions, Boulder, Colorado). Computations were performed in part using the facilities of the Washington University Center for High Performance Computing, which were partially provided through grant NCRR 1S10RR022984-01A1.Attached Files
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Additional details
- Eprint ID
- 71967
- Resolver ID
- CaltechAUTHORS:20161111-160255004
- NASA
- 110609
- Johns Hopkins University
- 77301-10534
- Cornell University
- 110609
- Caltech/JPL
- 1S10RR022984-01A1
- National Center for Research Resources (NCRR)
- Created
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2016-11-16Created from EPrint's datestamp field
- Updated
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2022-11-29Created from EPrint's last_modified field