Roger N Clark (Former Employee)

The last 16 years witnessed a rapid growth in understanding the composition and aqueous alteration of Mars’ surface from orbital data from the Observatoire pour la Mineralogie, l’Eau, les Glaces et l’Activité (OMEGA) [1] and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) [2]. Both are sensitive to water-, hydroxyl-, sulfate-, and carbonate-bearing and ferric phases that...

Remote surface measurements by imaging spectrometers play an important role in planetary and Earth science. To make these measurements, investigators calibrate instrument data to absolute units, invert physical models to estimate atmospheric effects, and then determine surface properties from the spectral reflectance. This study quantifies the uncertainty in this process. Global missions...

Natural and anthropogenic hazards have the potential to impact all aspects of society including its economy and the environment. Diagnostic data to inform decision-making are critical for hazard management whether for emergency response, routine monitoring or assessments of potential risks. Imaging spectroscopy (IS) has unique contributions to make via the ability to provide some key...

Isotopic ratios have long been used to learn about physical processes acting over a wide range of geological environments, and in constraining the origin and/or evolution of planetary bodies. We report the spectroscopic detection of deuterium in Saturn's rings and satellites, and use these measurements to determine the (D/H) ratios in their near-surface regions. Saturn's moons, Phoebe...

Ancient hydrothermal systems are a high-priority target for a future Mars sample return mission because they contain energy sources for microbes and can preserve organic materials (Farmer, 2000; MEPAG Next Decade Science Analysis Group, 2008; McLennan et al.,2012; Michalski et al.,2017). Characterizing these large, heterogeneous systems with a remote explorer is difficult due to...

Commercially produced vermiculite insulation from Libby, Montana, contains trace levels of asbestiform amphibole, which is known to cause asbestos-related diseases. When vermiculite insulation is found in a building, evaluation for its potential asbestos content traditionally involves collecting a sample from an attic or wall and submitting it for time-consuming analyses at an off-site...

We have assembled a library of spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns [μm]). Laboratory samples of specific minerals, plants, chemical compounds, and manmade materials were measured. In many cases, samples were purified, so that unique spectral features of a...

Cross crater is a 65 km impact crater, located in the Noachian highlands of the Terra Sirenum region of Mars (30°S, 158°W), which hosts aluminum phyllosilicate deposits first detected by the Observatoire pour la Minéralogie, L’Eau, les Glaces et l’Activitié (OMEGA) imaging spectrometer on Mars Express. Using high-resolution data from the Mars Reconnaissance Orbiter, we examine Cross...

IntroductionThis circular provides an overview of selected activities that were conducted within the U.S. Geological Survey (USGS) Integrated Methods Development Project, an interdisciplinary project designed to develop new tools and conduct innovative research requiring integration of geologic, geophysical, geochemical, and remote-sensing expertise. The project was supported by the USGS...

Imaging spectroscopy mapping software assists in the identification and mapping of materials based on their chemical properties as expressed in spectral measurements of a planet including the solid or liquid surface or atmosphere. Such software can be used to analyze field, aircraft, or spacecraft data; remote sensing datasets; or laboratory spectra. Tetracorder is a set of software...

Mineral maps based on Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data were used to study late Miocene advanced argillic alteration at Cuprite, Nevada. Distributions of Fe-bearing minerals, clays, micas, sulfates, and carbonates were mapped using the Tetracorder spectral-shape matching system. The Al content of white micas increases toward altered areas and near intrusive...

This chapter reviews detection of materials on solid and liquid (lakes and ocean) surfaces in the solar system using ultraviolet to infrared spectroscopy from space, or near space (high altitude aircraft on the Earth), or in the case of remote objects, earth-based and earth-orbiting telescopes. Point spectrometers and imaging spectrometers have been probing the surfaces of our solar...