SEARCH · Search NASA

Results for “Current mapping”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69

All sources NASA NTRS DOE OSTI

NASA NTRS1988

Computing motion using resistive networks

Recent developments in the theory of early vision are described which lead from the formulation of the motion problem as an ill-posed one to its solution by minimizing certain 'cost' functions. These cost or energy functions can be mapped onto simple analog and digital resistive networks. It is shown how the optical flow can be computed by injecting currents into resistive networks and recording the resulting stationary voltage distribution at each node. These networks can be implemented in cMOS VLSI circuits and represent plausible candidates for biological vision systems.

Koch, Christof↗

NASA NTRS1990

Geologic setting of diverse volcanic materials in northern Elysium Planitia, Mars

Geologic mapping of high-resolution (30-50 m/pixel) Viking Orbiter images of northern Elysium Planitia has identified seven sites where current problems in martian volcanology, chronology, and stratigraphy can be resolved. These sites, which are discussed in the context of a potential Mars rover/sample return mission, would permit the following investigations: (1) the dating of Lower Amazonian lava flows from Elysium Mons (thereby providing absolute calibration for global crater size/frequency relative chronologies, (2) the petrologic investigation of long run-out lava flows, (3) the geologic interpretation of materials that may either be lava flows or lahar deposits, (4) the analysis of materials believed to be ash deposits produced by explosive eruptions of Hecates Tholus, and (5) the investigation of the stratigraphy of fractured terrain along the boundary between northern Elysium Planitia and southern Utopia Planitia.

Mouginis-Mark, P. J.↗

NASA NTRS1991

Processing Particle-Streak Imagery On A Personal Computer

Report describes simple flow experiment in which streak images of particles suspended in fluid and illuminated for short times processed into maps of velocity vectors. In experiment, semiautomatic data-reduction scheme used which recovers significant image data more efficiently than currently available automatic scheme.

Cho, Y. C.↗

NASA NTRS1999

Tidal Energy Available for Deep Ocean Mixing: Bounds from Altimetry Data

Maintenance of the large-scale thermohaline circulation has long presented an interesting problem. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

Ray, Richard D.↗

NASA NTRS1999

Tidal Energy Available for Deep Ocean Mixing: Bounds From Altimetry Data

Maintenance of the large-scale thermohaline circulation has long presented a problem to oceanographers. Observed mixing rates in the pelagic ocean are an order of magnitude too small to balance the rate at which dense bottom water is created at high latitudes. Recent observational and theoretical work suggests that much of this mixing may occur in hot spots near areas of rough topography (e.g., mid-ocean ridges and island arcs). Barotropic tidal currents provide a very plausible source of energy to maintain these mixing processes. Topex/Poseidon satellite altimetry data have made precise mapping of open ocean tidal elevations possible for the first time. We can thus obtain empirical, spatially localized, estimates of barotropic tidal dissipation. These provide an upper bound on the amount of tidal energy that is dissipated in the deep ocean, and hence is available for deep mixing. We will present and compare maps of open ocean tidal energy flux divergence, and estimates of tidal energy flux into shallow seas, derived from T/P altimetry data using both formal data assimilation methods and empirical approaches. With the data assimilation methods we can place formal error bars on the fluxes. Our results show that 20-25% of tidal energy dissipation occurs outside of the shallow seas, the traditional sink for tidal energy. This suggests that up to 1 TW of energy may be available from the tides (lunar and solar) for mixing the deep ocean. The dissipation indeed appears to be concentrated over areas of rough topography.

Egbert, Gary D.↗

NASA NTRS2002

Space Radiation Transport Methods Development

Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary design concepts to the final design. In particular, we will discuss the progress towards a full three-dimensional and computationally efficient deterministic code for which the current HZETRN evaluates the lowest order asymptotic term. HZETRN is the first deterministic solution to the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard Finite Element Method (FEM) geometry common to engineering design practice enabling development of integrated multidisciplinary design optimization methods. A single ray trace in ISS FEM geometry requires 14 milliseconds and severely limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given in terms of reconfigurable computing and could be utilized in the final design as verification of the deterministic method optimized design.

Wilson, J. W.↗

NASA NTRS2006

X-Ray Detector Research at MSFC for Space Applications

NASA's Vision for Space Exploration has specific goals aimed at exploring the Solar System. This vision, under presidential mandate includes landing humans on the moon before the end of the next decade, paving the way for eventual journeys to Mars and beyond. The first missions to the moon will be in the form of both Orbiters and Landers, with the goal of paving the way for human return. One of the instruments we are currently working on,in collaboration with Brookhaven National Laboratory, is a lunar orbiter fluorescent x-ray spectrometer to finely map the light elements (down to Carbon) on surface of the moon. Funded NASA s Planetary Instrument Definition and Development Program the instrument is based on silicon drift detector arrays read out by custom ASICs. These offer the promise of high spectral resolution, necessary for resolving weak lines against a strong background continuum, and very low power requirements, necessary for large areas (greater than 500 square centimeters) required for future lunar missions. Further, the inherent radiation hardness of these detectors makes them ideal candidates for exploring the Jovian system, where the harsh radiation environment from Jupiter s radiation belts creates unfavorable detector conditions. Looking beyond our solar system, in the hard x-ray regime (20-80keV.), we are studying Cadmium-Zinc-Telluride pixilated detectors as feasible candidates for focal plane detectors of a hard x-ray telescope. This energy region bridges the gap between thermal and non-thermal x-ray emission from astronomical sources, will allow us to better understand supernovae nucleosynthesis (such as through the Ti-44 lines at 68keV and 78keV), Active Galactic Nuclei and other compact objects, more completely. The detectors that we are characterizing are 2mm in thickness and are pixilated with a 16x16 array of 300 micrometer pitch pixels (50micometer gap). These detectors are designed at Rutherford Appleton Laboratory, material is from eV Products, and polymer flip-chip assembly was performed by a commercial vendor. An energy resolution of 2.0% at 60keV (or better) should allow us to sufficiently distinguish lines of interest from background continuum, and the detector spatial resolution should be fine enough to over-sample the focal spot from the x-ray focusing optics by about a factor of two. Full technical details of these developments will be presented.

Gaskin, Jessica↗

NASA NTRS2004

Societal Benefits of Ocean Altimetry Data

The NASA/CNES Jason satellite, follow-on to the highly successful TOPEX/Poseidon mission, continues to provide oceanographers and marine operators across the globe with a continuous twelve-year, high quality stream of sea surface height data. The mission is expected to extend through 2007, when the NASA/NOAA/CNES follow-on mission, OSTM, will be launched with the wide-swath ocean altimeter on board. This unprecedented resource of valuable ocean data is being used to map sea surface height, geostrophic velocity, significant wave height, and wind speed over the global oceans. Altimeter data products are currently used by hundreds of researchers and operational users to monitor ocean circulation and improve our understanding of the role of the oceans in climate and weather. Ocean altimeter data has many societal benefits and has proven invaluable in many practical applications including; a) Ocean forecasting systems; b) Climate research and forecasting; c) Ship routing; d) Fisheries management; e) Marine mammal habitat monitoring; f) Hurricane forecasting and tracking; g) Debris tracking; and h) Precision marine operations such as cable-laying and oil production. The data has been cited in nearly 2,000 research and popular articles since the launch of TOPEX/Poseidon in 1992, and almost 200 scientific users receive the global coverage altimeter data on a monthly basis. In addition to the scientific and operational uses of the data, the educational community has seized the unique concepts highlighted by these altimeter missions as a resource for teaching ocean science to students from grade school through college. This presentation will highlight societal benefits of ocean altimetry data in the areas of climate studies, marine operations, marine research, and non-ocean investigations.

sea surface height↗

NASA NTRS2008

Simultaneous Noncontact Precision Imaging of Microstructural and Thickness Variation in Dielectric Materials Using Terahertz Energy

This article describes a noncontact single-sided terahertz electromagnetic measurement and imaging method that simultaneously characterizes microstructural (egs. spatially-lateral density) and thickness variation in dielectric (insulating) materials. The method was demonstrated for two materials-Space Shuttle External Tank sprayed-on foam insulation and a silicon nitride ceramic. It is believed that this method can be used as an inspection method for current and future NASA thermal protection system and other dielectric material inspection applications, where microstructural and thickness variation require precision mapping. Scale-up to more complex shapes such as cylindrical structures and structures with beveled regions would appear to be feasible.

Roth, Don J.↗

NASA NTRS2008

Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars: Introductory Report

Geologic mapping studies at the 1:1M-scale will be used to characterize geologic processes that have shaped the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary will provide the ability to: 1) further test original dichotomy formation hypotheses, 2) constrain ancient paleoenvironments and climate conditions, and 3) evaluate various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The result will be two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

Bleamaster, Leslie F., III↗

NASA NTRS2009

Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars

Geologic mapping studies at the 1:1M-scale are being used to assess geologic materials and processes that shape the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary may provide constraints on: 1) origin of the dichotomy boundary, 2) paleo-environments and climate conditions, and 3) various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The results of this work will include two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

Bleamaster, Leslie F., III↗

NASA NTRS2011

Observations of a High-Latitude Stable Electron Auroral Emission at Approximately 16 MLT During a Large Substorm

During an interval when the interplanetary magnetic field was large and primarily duskward and southward, a stable region of auroral emission was observed on 17 August 2001 by IMAGE at 16 magnetic local time, poleward of the main aurora, for 1 h, from before the onset of a large substorm through the recovery phase. In a region where ions showed the energy dispersion expected for the cusp, strong field \aligned currents and Poynting flux were observed by Polar (at 1.8 RE in the Southern Hemisphere) as it transited field lines mapping to the auroral spot in the Northern Hemisphere. The data are consistent with the hypothesis that the long \lasting electron auroral spot maps to the magnetopause region where reconnection was occurring. Under the assumption of conjugacy between the Northern and Southern hemispheres on these field lines, the Polar data suggest that the electrons on these field lines were accelerated by Alfven waves and/or a quasi \static electric field, primarily at altitudes below a few RE since the in situ Poynting flux (mapped to 100 km) is comparable to the energy flux of the emission while the mapped in situ electron energy flux is much smaller. This event provides the first example of an emission due to electrons accelerated at low altitudes at the foot point of a region of quasi \steady dayside reconnection. Cluster data in the magnetotail indicate that the Poynting flux from the reconnection region during this substorm is large enough to account for the observed nightside aurora.

Cattell, C.↗

NASA NTRS2016

Developing Atmospheric Retrieval Methods for Direct Imaging Spectroscopy of Gas Giants in Reflected Light I: Methane Abundances and Basic Cloud Properties

Reflected light spectroscopy and photometry of cool, directly imaged extrasolar giant planets are expected to be performed in the next decade by space-based telescopes equipped with optical wavelength coronagraphs and integral field spectrographs, such as the Wide-Field Infrared Survey Telescope (WFIRST). We are developing a new atmospheric retrieval methodology to help assess the science return and inform the instrument design for such future missions, and ultimately interpret the resulting observations. Our retrieval technique employs an albedo model coupled with both a Markov chain Monte Carlo Ensemble Sampler (emcee) and a multimodal nested sampling algorithm (MultiNest) to map the posterior distribution. This combination makes the global evidence calculation more robust for any given model, and highlights possible discrepancies in the likelihood maps. Here we apply this methodology to simulated spectra of cool giant planets. As a proof-of-concept, our current atmospheric model contains 1 or 2 cloud layers, methane as a major absorber, and a H2-He background gas. This 6-to-9 parameter model is appropriate for Jupiter-like planets and can be easily expanded in the future. In addition to deriving the marginal likelihood distribution and confidence intervals for the model parameters, we perform model selection to determine the significance of methane and cloud detection as a function of expected signal-to-noise, in the presence of spectral noise correlations. After internal validation, the method is applied to realistic reflected-light spectra of Jupiter, Saturn, and HD 99492 c, a likely observing target. We find that the presence or absence of clouds and methane can be determined with high accuracy, while parameters uncertainties are model-dependent.

spectroscopy↗

NASA NTRS2017

PHYS: Division of Physical Chemistry 258 - Properties and Origins of Cometary and Asteroidal Organic Matter Delivered to the Early Earth

Comets and asteroids may have contributed much of the Earth's water and organic matter. The Earth accretes approximately 4x10(exp 7) Kg of dust and meteorites from these sources every year. The least altered meteorites contain complex assemblages of organic compounds and abundant hydrated minerals. These carbonaceous chondrite meteorites probably derive from asteroids that underwent hydrothermal processing within the first few million years after their accretion. Meteorite organics show isotopic and chemical signatures of low-T ion-molecule and grain-surface chemistry and photolysis of icy grains that occurred in cold molecular clouds and the outer protoplanetary disk. These signatures have been overprinted by aqueously mediated chemistry in asteroid parent bodies, forming amino acids and other prebiotic molecules. Comets are much richer in organic matter but it is less well characterized. Comet dust collected in the stratosphere shows larger H and N isotopic anomalies than most meteorites, suggesting better preservation of primordial organics. Rosetta studies of comet 67P coma dust find complex organic matter that may be related to the macromolecular material that dominates the organic inventory of primitive meteorites. The exogenous organic material accreting on Earth throughout its history is made up of thousands of molecular species formed in diverse processes ranging from circumstellar outflows to chemistry at near absolute zero in dark cloud cores and the formative environment within minor planets. NASA and JAXA are currently flying sample return missions to primitive, potentially organic-rich asteroids. The OSIRIS-REx and Hayabusa2 missions will map their target asteroids, Bennu and Ryugu, in detail and return regolith samples to Earth. Laboratory analyses of these pristine asteroid samples will provide unprecedented views of asteroidal organic matter relatively free of terrestrial contamination within well determined geological context. Studies of extraterrestrial materials and returned samples are essential to understand the origins of Solar System organic material and the roles of comets and asteroids to providing the starting materials for the emergence of life.

Messenger, Scott↗

NASA NTRSDate not supplied

Tracking the Hunga Tonga-Hunga Ha’apai Eruption Stratospheric Aerosol and Trace Gas Plumes Using Machine Learning

On January 15, 2022, the Hunga Tonga-Hunga Ha’apai (hereafter, Hunga Tonga) submarine volcano had an explosive eruption that thrusted ash, gases, and water vapor through the troposphere into the stratosphere and mesosphere. Previous studies manually tracked the aerosol and trace gas plumes over time across different positions in the southern hemisphere. Using data retrieved from low earth orbiting satellite instruments (e.g., OMPS, OMI, and CALIPSO), this research demonstrates how open-source machine learning (ML) models, like Meta’s Segment Anything Model (SAM), with prompt engineering can perform automatic plume tracking following the Hunga Tonga eruption. This extensible methodology, and modular data processing and modeling pipeline using NASA Earthdata and Openscapes, establishes a framework for systematically and rapidly studying extreme events, including volcanic eruptions and large-scale wildfires. By combining advanced machine learning techniques, such as SAM’s zero-shot learning, with large volumes of remote sensing data, this work demonstrates how AI and open science can accelerate research and generate actionable results. The tools and technologies presented here can help translate earth science to action from NASA’s current and future Earth observing satellite missions (e.g., the Atmosphere Observing System (AOS)), and assist researchers and stakeholders in understanding, mapping, and responding to natural disasters and extreme events in a changing world.

David M. Giles↗

DOE OSTI2016

Public Health Analysis Transport Optimization Model v. 1.0

PHANTOM models logistic functions of national public health systems. The system enables public health officials to visualize and coordinate options for public health surveillance, diagnosis, response and administration in an integrated analytical environment. Users may simulate and analyze system performance applying scenarios that represent current conditions or future contingencies what-if analyses of potential systemic improvements. Public health networks are visualized as interactive maps, with graphical displays of relevant system performance metrics as calculated by the simulation modeling components.

Beyeler, Walt↗

DOE OSTI2020

Feature Engineering and Process Mining to Enable Hazard Detection in Health Information Technology

Motivation for this work originates from a recognized need for developing data-driven approaches through analysis of complex electronic health records. Specifically, we aim to enhance the reliability of health information technology (HIT) systems by detection of plausible HIT hazards in clinical order transactions. In the absence of well-defined event logs in corporate data warehouses, our proposed approach identifies relevant timestamped data fields that could indicate transactions in the clinical order life cycle generating raw event sequences. Subsequently, we adopt state transitions of the OASIS Human Task standard to map the raw event sequences and simplify the complex process that clinical radiology orders go through. We describe how the current approach provides the potential to investigate areas of improvement and potential hazards in HIT systems. The discussion concludes with a use case and opportunities for future applications.

Ozmen, Ozgur↗

DOE OSTI2016

Isotropy-violation diagnostics for B -mode polarization foregrounds to the Cosmic Microwave Background

Isotropy-violation statistics can highlight polarized galactic foregrounds that contaminate primordial B -modes in the Cosmic Microwave Background (CMB). We propose a particular isotropy-violation test and apply it to polarized Planck 353 GHz data, constructing a map that indicates B -mode foreground dust power over the sky. We build our main isotropy test in harmonic space via the bipolar spherical harmonic basis, and our method helps us to identify the least-contaminated directions. By this measure, there are regions of low foreground in and around the BICEP field, near the South Galactic Pole, and in the Northern Galactic Hemisphere. There is also a possible foreground feature in the BICEP field. In our study, we compare our results to those based on the local power spectrum, which is computed on discs using a version of the method of Planck Int. XXX (2016). The discs method is closely related to our isotropy-violation diagnostic. We pay special care to the treatment of noise, including chance correlations with the foregrounds. Currently we use our isotropy tool to assess the cleanest portions of the sky, but in the future such methods will allow isotropy-based null tests for foreground contamination in maps purported to measure primordial B -modes, particularly in cases of limited frequency coverage.

79 ASTRONOMY AND ASTROPHYSICS↗