A5053219234- Planetary Science and Exploration
- Geochemistry and Geologic Mapping
- Remote-Sensing Image Classification
- Astro and Planetary Science
- Space Exploration and Technology
- Advanced Image Fusion Techniques
- Spectroscopy and Chemometric Analyses
- Paleontology and Stratigraphy of Fossils
- Image Processing and 3D Reconstruction
- Sparse and Compressive Sensing Techniques
- Geology and Paleoclimatology Research
- Image Retrieval and Classification Techniques
- Mineral Processing and Grinding
- Atmospheric and Environmental Gas Dynamics
- Marine and environmental studies
- Space Science and Extraterrestrial Life
- Scientific Research and Discoveries
- Spectroscopy Techniques in Biomedical and Chemical Research
- Isotope Analysis in Ecology
- Image Processing Techniques and Applications
- Image and Signal Denoising Methods
- Hydrocarbon exploration and reservoir analysis
- Optical Imaging and Spectroscopy Techniques
- Remote Sensing and Land Use
- Industrial Vision Systems and Defect Detection
University of Massachusetts Amherst
2015-2024
Stanford University
2006-2019
Amherst College
2019
Mitsubishi Electric (Japan)
2019
University of Electro-Communications
2019
Tohoku University
2019
Tokyo Denki University
2019
Nagoya University
2019
Niigata University
2019
University of Massachusetts Boston
2016
Imaging spectrometers measure electromagnetic energy scattered in their instantaneous field view hundreds or thousands of spectral channels with higher resolution than multispectral cameras. are therefore often referred to as hyperspectral cameras (HSCs). Higher enables material identification via spectroscopic analysis, which facilitates countless applications that require identifying materials scenarios unsuitable for classical analysis. Due low spatial HSCs, microscopic mixing, and...
Observations by the Mars Reconnaissance Orbiter/Compact Imaging Spectrometer for in Mawrth Vallis region show several phyllosilicate species, indicating a wide range of past aqueous activity. Iron/magnesium (Fe/Mg)–smectite is observed light-toned outcrops that probably formed via alteration basalt ancient cratered terrain. This unit overlain rocks rich hydrated silica, montmorillonite, and kaolinite may have subsequent leaching Fe Mg through extended events or change chemistry. A spectral...
Juventae Chasma contains four light‐toned sulfate‐bearing mounds (denoted here as A–D from west to east) inside the trough, mafic outcrops at base of and in wall rock, layered deposits opal ferric sulfates on plateau. Hyperspectral visible/near‐infrared Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectra were used identify monohydrated polyhydrated sulfate (PHS) material bright mounds. Most signatures closely resemble those szomolnokite (FeSO 4 ·H 2 O), characterized by a...
New results from the Compact Reconnaissance Imaging Spectrometer for Mars and High Resolution Science Experiment Context Imager cameras on Orbiter provide insights into origin of interior layered deposits in Valles Marineris analysis a thick, well‐exposed section western Candor Chasma. Most deposit is dominated spectrally by nanophase ferric oxide like that found globally distributed eolian dust, with addition prevalent component monohydrated sulfates. A rippled mantle containing both...
Mawrth Vallis contains one of the largest exposures phyllosilicates on Mars. Nontronite, montmorillonite, kaolinite, and hydrated silica have been identified throughout region using data from Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). In addition, saponite has in observation within a crater. These individual minerals are distinguished by features at 1.38–1.42, ∼1.91, 2.17–2.41 μ m. There two main phyllosilicate units region. The lowermost unit is nontronite bearing,...
Abstract Silica has the highest demonstrated potential of any phase to preserve microfossils on Earth and therefore may host biosignatures Mars. We detected hydrated silica in Jezero crater, landing site National Aeronautics Space Administration's Mars 2020 rover mission, by applying Dynamic Aperture Factor Analysis/Target Transformation images from Compact Reconnaissance Imaging Spectrometer for Hydrated detections with were verified using commonly accepted analysis methods. The morphology...
Spectral mixture analysis (also called spectral unmixing) has been an alluring exploitation goal since the earliest days of imaging spectroscopy. No matter spatial resolution, signatures collected in natural environments are invariably a various materials found within extent ground instantaneous field view instrument. In this paper, we give comprehensive enumeration unmixing methods used practice, because their implementation widely software packages, and those published literature. We have...
Visible, near-infrared, thermal, and Mössbauer spectroscopic data from the exposed, bright track soil at "Paso Robles" site within Gusev crater, Mars, indicate presence of Fe3+-sulfates possibly Fe3+-phosphates admixed with host soil. When analyses are combined constraints imposed by chemical data, determined dominant Fe3+-sulfate component is hydrous, all methods suggest that it probably ferricopiapite or some closely related, structurally similar species, mixed other Fe3+ sulfates such as...
Abstract There is ample evidence of both ancient and long‐lasting fluvial activity chemical alteration in the Libya Montes region south Isidis Basin. The hosts Noachian to Amazonian aged surface rocks with extensive outcrops olivine‐ pyroxene‐bearing material. also features and/or deposits hosting Fe/Mg‐smectite, Fe/Mg‐smectite mixed carbonate other Fe/Mg‐rich phyllosilicates, Al‐smectite. These units likely formed through connected hydrothermal resulting from formation Basin pervasive...
Superpixel segmentation algorithms attempt to group contiguous image pixels which are in homogeneous regions into segments (superpixels). maps have proven successful improving the performance of unmixing on hyperspectral images. For images (HSIs), segment members must contain spectrally similar pixels, a requirement we refer as uniformity. Existing superpixel been applied HSIs provide no guarantees uniformity inside segments. In absence such guarantees, only viable option is make small...
High spectral resolution brings hyperspectral images with large amounts of information, which makes these more useful in many applications than obtained from traditional multispectral scanners low resolution. However, the high data dimensionality increases burden on computation, storage, and transmission; fortunately, redundancy domain allows for significant reduction. Band selection provides a simple reduction scheme by discarding bands that are highly redundant, thereby preserving...
Abstract Carbonate minerals have been detected in Jezero crater, an ancient lake basin that is the landing site of Mars 2020 Perseverance rover, and within regional olivine‐bearing (ROB) unit Nili Fossae region surrounding this crater. It has suggested some carbonates margin fractured unit, a rock formed fluviolacustrine environment, which would be conducive to preservation biosignatures from paleolake‐inhabiting lifeforms. Here, we show carbonate‐bearing rocks outside crater same range...
We consider the problem of factorizing a hyperspectral image into product two nonnegative matrices, which represent bases for spectra and mixing coefficients, respectively. This spectral unmixing is nonconvex optimization problem, very difficult to solve exactly. present simple heuristic approximately solving this based on idea alternating projected subgradient descent. Finally, we results applying method 1990 AVIRIS Cuprite, Nevada show that our are in agreement with similar studies same data.
The primary objective of NASA's Mars Science Laboratory (MSL) mission, which will launch in 2011, is to characterize the habitability a site on through detailed analyses composition and geological context surface materials. Within framework established mission goals, we have evaluated value possible landing Mawrth Vallis region that targeted directly some most geologically astrobiologically enticing materials Solar System. area around contains vast (>1 × 106 km2) deposit phyllosilicate-rich,...
Refined calibrations of CRISM images are enabling identification smaller deposits unique aqueous materials on Mars that reveal changing environmental conditions at the region surrounding Mawrth Vallis. Through characterization these clay-sulfate assemblages and their association with layered, phyllosilicate units this region, more details geochemical history can be gleaned. A stratigraphy including five distinct mineral horizons is mapped using compositional data from over CTX HRSC imagery...
Olivine group minerals are ubiquitous in extrusive igneous rocks and play an important role constraining equilibria for samples the upper mantle above. All Raman spectra of olivine solid solution between forsterite (Fo, Mg2SiO4) fayalite (Fa, Fe2SiO4) have a high-intensity doublet 800 880 cm–1. Previous studies used small sample suites with limited compositional ranges varying spectrometers to relate energy shifts these two bands Mg/Fe contents. In this work, 93 were acquired on either...
Abstract Previous studies have shown that Mt. Sharp has stratigraphic variation in mineralogy may record a global transition from climate more conducive to clay mineral formation one marked by increased sulfate production. To better understand how small‐scale observations along the traverse path of NASA's Curiosity rover might be linked such large‐scale processes, it is necessary extent which signatures observed orbit vary laterally and vertically. This study uses newly processed...
The simulation of remote-sensing hyperspectral images is a useful tool for variety tasks such as the design systems, understanding image formation process, and development validation data processing algorithms. lack ground truth incomplete knowledge Martian environment make studies Mars automated analysis data. Hyperspectral near-infrared scenes mineral mixtures have been simulated to analyze contributions surface minerals, atmosphere, sensor noise on Mars. Modeling process creates means...