Abstract. The Thermal Emission Spectrometer (TES) investigation on Mars GlobalThe TES data are calibrated to a 1-o-precision of 2.5 -6 X 10 -8 W cm -2 sr-1/cm -•, 1.6 x 10 -6 W cm -2 sr -•, and -0.5 K in the spectrometer, visible/near-IR bolometer, and IR bolometer, respectively_. These instrument subsections are calibrated to an absolute accuracy of-4 x 10 -8 W cm -2 sr-•/cm -• (0.5 K at 280 K), 1-2%, and -1-2 K, respectively. Global mapping of surface mineralogy at a spatial resolution of 3 km has shown the following: (1) The mineralogic composition of dark regions varies from basaltic, primarily plagioclase feldspar and clinopyroxene, in the ancient, southern highlands to andesitic, dominated by plagioclase feldspar and volcanic glass, in the younger northern plains. (2) Aqueous mineralization has produced gray, crystalline hematite in limited regions under ambient or hydrothermal conditions; these deposits are interpreted to be in-place sedimentary rock formations and indicate that liquid water was stable near the surface for a long period of time. (3) There is no evidence for large-scale (tens of kilometers) occurrences of moderate-grained (>50-•m) carbonates exposed at the surface at a detection limit of -10%. (4) Unweathered volcanic minerals dominate the spectral properties of dark regions, and weathering products, such as clays, have not been observed anywhere above a detection limit of -10%; this lack of evidence for chemical weathering indicates a geologic history dominated by a cold, dry climate in which mechanical, rather than chemical, weathering was the significant form of erosion and sediment production. (5) There is no conclusive evidence for sulfate minerals at a detection limit of -15%. The polar region has been studied with the following major conclusions: (1) Condensed CO2 has three distinct end-members, from fine-grained crystals to slab ice. (2) The growth and retreat of the polar caps observed by MGS is virtually the same as observed by Viking 12 Martian years ago. (3) Unique regions have been identified that appear to differ primarily in the grain size of CO2; one south polar region appears to remain as black slab CO2 ice throughout its sublimation. (4) Regional atmospheric dust is common in localized and regional dust storms around the margin and interior of the southern cap. Analysis of the thermophysical properties of the surface shows that (1) the spatial pattern of albedo has changed since Viking observations, (2) a unique cluster of surface materials with intermediate inertia and albedo occurs that is distinct from the previously identified lowinertia/bright and high-inertia/dark surfaces, and (3) localized patches of high-inertia material have been found in topographic lows and may have been formed by a unique set of aeolian, fluvial, or erosional processes or may be exposed bedrock.• •Raytheon Santa Barbara Remote Sensing, Goleta, California. IntroductionThe Thermal Emission Spectrometer (TES) experiment is designed to address a wide range of science objectives, including the de...
[1] The mosaicking of global planetary data sets allows for the examination of local, regional, and global scale processes on all planetary bodies. Processing techniques that allow us and other users to crate mosaics of tens of thousands of images are documented along with the associated errors introduced by each image-processing algorithm. These techniques (e.g., non-uniformity correction, running contrast stretches, line and row correlated noise removal, and random noise removal) were originally developed for the 2001 Mars Odyssey Thermal Emission Imaging System (THEMIS) infrared multispectral imager data but can be adapted and applied to other data sets by the alteration of input parameters. The techniques for mosaicking planetary image data sets (e.g., image registration, blending, and normalization) are also presented along with the generation of qualitative and quantitative products. These techniques are then applied to generate THEMIS daytime and nighttime infrared, Viking, Context Imager (CTX), and Mars Orbiter Camera (MOC) visible mosaics using a variety of input and output types at a variety of scales. By creating mosaics of the same area using different data sets such as those that illustrate compositional diversity, thermophysical properties, or small-scale morphology, it is possible to view the surface of the planet and geologic problems through many different perspectives. In addition to the techniques used to create large-scale seamless mosaics, we also present the THEMIS daytime and nighttime relative temperature global mosaics, which are the highest resolution (100m/pixel) global scale data sets available for Mars to date.
Gale crater is the landing site of the Mars Science Laboratory (MSL) rover, Curiosity. Here we present Thermal Emission Imaging System Visible Imaging Subsystem (THEMIS‐VIS) mosaics in gray scale and in false color of Gale crater. We use these data products, in addition to THEMIS thermal infrared decorrelation stretch (DCS) mosaics, thermal inertia derivations, and near‐infrared spectra to investigate the MSL traverse area and sand across Gale crater. We identified several THEMIS‐VIS color units in the MSL traverse area that may correlate to the amount of sand cover that is present on each unit. This suggests that THEMIS‐VIS color is extremely useful in identifying dark basaltic sand, which appears as blue in THEMIS‐VIS false color images. We test this hypothesis by identifying small (~several pixels) blue patches on the southeast side of the central mound in Gale crater and confirming that they are patches of sand in High Resolution Imaging Science Experiment (HiRISE) images. Sand dunes on the crater floor exhibit variations in all data sets utilized in this study, with the Bagnold dunes and the western sand sea exhibiting the most notable differences. We propose that these differences are the result of a thin layer of dust that covers the western sand sea, although we do not rule out possible effects from grain size sorting.
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