Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “in situ visualization”

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.

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

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

Pore Formation and Mobility Investigation (PPMI): Description and Initial Analysis of Experiments Conducted aboard the International Space Station

Flow visualization experiments during the controlled directional melt back and re-solidification of succinonitrile (SCN) and SCN-water mixtures were conducted using the Pore Formation and Mobility Investigation (PFMI) apparatus in the glovebox facility (GBX) aboard the International Space Station. The study samples were initially 'cast' on earth under 450 millibar of nitrogen into 1 cm ID glass sample tubes approximately 30 cm in length, containing 6 in situ thermocouples. During the Space experiments, the processing parameters and flow visualization settings are remotely monitored and manipulated from the ground Telescience Center (TSC). The ground solidified sample is first subjected to a unidirectional melt back, generally at 10 microns per second, with a constant temperature gradient ahead of the melting interface. Bubbles of different sizes are seen to initiate at the melt interface and, upon release from the melting solid, translate at different speeds in the temperature field ahead of them before coming to rest. Over a period of time these bubbles dissolve into the melt. The gas-laden liquid is then directionally solidified in a controlled manner, generally starting at a rate of 1 micron /sec. Observation and preliminary analysis of bubble formation and mobility in pure SCN samples during melt back and the subsequent structure resulting during gas generation upon re-solidification are presented and discussed.

Grugel, R. N.↗
NASA NTRS2002

Pore Formation and Mobility Investigation (PFMI): Description and Initial Analysis of Experiments Conducted aboard the International Space Station

Flow visualization experiments during the controlled directional melt back and re-solidification of succinonitrile (SCN) and SCN-water mixtures were conducted using the Pore Formation and Mobility Investigation (PFMI) apparatus in the glovebox facility (GBX) aboard the International Space Station. The study samples were initially "cast" on earth under 450 millibar of nitrogen into 1 cm ID glass sample tubes approximately 30 cm in length, containing 6 in situ thermocouples. During the Space experiments, the processing parameters and flow visualization settings are remotely monitored and manipulated from the ground Telescience Center (TSC). The ground solidified sample is first subjected to a unidirectional melt back, generally at 10 microns per second, with a constant temperature gradient ahead of the melting interface. Bubbles of different sizes are seen to initiate at the melt interface and, upon release from the melting solid, translate at different speeds in the temperature field ahead of them before coming to rest. Over a period of time these bubbles dissolve into the melt. The gas-laden liquid is then directionally solidified in a controlled manner, generally starting at a rate of 1 micron /sec. Observation and preliminary analysis of bubble formation and mobility in pure SCN samples during melt back and the subsequent structure resulting during gas generation upon re-solidification are presented and discussed.

Grugel, R. N.↗
NASA NTRS2002

Crystal Growth of ZnSe and Related Ternary Compound Semiconductors by Vapor Transport

The objective of the project is to determine the relative contributions of gravity-driven fluid flows to the compositional distribution, incorporation of impurities and defects, and deviation from stoichiometry observed in the crystals grown by vapor transport as results of buoyance-driven convection and growth interface fluctuations caused by irregular fluid-flows. ZnSe and related ternary compounds, such as ZnSeS and ZnSeTe, were grown by vapor transport technique with real time in-situ non-invasive monitoring techniques. The grown crystals were characterized extensively to correlate the grown crystal properties with the growth conditions. The following are the research progress in the past two years. In-situ monitoring of partial pressure by optical absorption technique and visual observation of the growing crystal were performed during vapor growth of ZnSe. Low-temperature photoluminescence (PL) spectra and glow discharge mass spectroscopy (GDMS) were measured on ZnSe starting materials provided by various vendors and on bulk crystals grown from these starting materials by physical vapor transport (PVT) to study the effects of purification and contamination during crystal growth process. Optical characterization was performed on wafers sliced from the grown crystals of ZnSe, ZnTe and ZnSe(1-x),Te(x), (0<x<0.4). Energy band gaps at room temperature were determined from optical transmission measurements and a best fit curve to the band gap vs. composition, x, data gives a bowing parameter of 1.45. Low-temperature photoluminescence (PL) spectra of ZnSe and ZnTe were dominated by near band edge emissions and no deep donor-acceptor pairs were observed. The PL spectrum exhibited a broad emission for the ZnSe(1-x),Te(x), samples, 0.09<x<0.39. The single broad PL emission spectra and the spectra measured as a function of temperature were interpreted as being associated with the exciton bound to Te clusters because of the high Te content in these samples. To validate numerical codes, in-situ monitoring during the PVT of HgI2 was designed. Optical absorption spectra of the vapor phase over HgI2 were measured for wavelengths between 200 and 600nm at sample temperatures between 349 and 610K. The Beer's Law constants for 15 wavelengths between 200 and 440 nm were determined. From these constants the vapor pressure of HgI2 was established as a function of temperature for the liquid and the solid Beta-phases To characterize the growth conditions during the PVT growth of In-doped ZnSe the optical absorbance of the vapor phase over the In-Se system were measured and were used to obtain the partial pressures of Se2(g) and In2Se(g).

Su, Ching-Hua↗
NASA NTRS2004

Undercut Rocks at the MER Gusev Landing Site

On January 3 2004, the NASA Spirit rover landed on the plains inside the Gusev Crater in the southern hemisphere of Mars, and has made observations of the landing site and nearby region in visual and infrared wavelengths, as well as making in-situ measurements of rocks and soil. A number of rocks at the Gusev site are perched, with a significant undercut above the surface; additional rocks show a feature of being eroded or etched at a height of one to three centimeters immediately above the soil line. Some rocks also show terracing, and others show a two-tone pattern of albedo, with a distinct dividing line between a lighter area near the surface and a darker color above the surface. In a small number of cases, the dividing line is correlated with a visible horizontal groove in the rock, most likely indicating an earlier location of burial of the rock. A number of explanations for this undercutting are possible. Perched rocks can be placed on the surface by deflation of the soil from underneath the rock. The surface etching may be abrasion due to reptation. Reptation, or surface creep, occurs as sand moves without leaving the surface, as small (100-200 micron particles) moved by saltation set larger particles in motion. These large particles are effective at abrading the rocks at the surface level. The structure of "ripple" features at the site is evidence to support reptation at the Gusev site. An alternate explanation is etching at the surface by chemically active grit.

Landis, Geoffrey A.↗
NASA NTRS2020

Barefoot Rover: a Sensor-Infused Rover Wheel Demonstrating In-Situ Engineering and Science Extractions using Machine Learning

In this work, we demonstrate an instrumented wheel concept which utilizes a 2D pressure grid, an electrochemical impedance spectroscopy (EIS) sensor and machine learning (ML) to extract meaningful metrics from the interaction between the wheel and surface terrain. These include continuous slip/skid estimation, balance, and sharpness for engineering applications. Estimates of surface hydration, texture, terrain patterns, and regolith physical properties such as cohesion and angle of internal friction are additionally calculated for science applications. Traditional systems rely on post-processing of visual images and vehicle telemetry to estimate these metrics. Through in-situ sensing, these metrics can be calculated in near real time and made available to onboard science and engineering autonomy applications. This work aims to provide a deployable system for future planetary exploration missions to increase science and engineering capabilities through increased knowledge of the terrain.

Marchetti, Yuliya↗
NASA NTRS2000

Photogrammetry Applied to Wind Tunnel Testing

In image-based measurements, quantitative image data must be mapped to three-dimensional object space. Analytical photogrammetric methods, which may be used to accomplish this task, are discussed from the viewpoint of experimental fluid dynamicists. The Direct Linear Transformation (DLT) for camera calibration, used in pressure sensitive paint, is summarized. An optimization method for camera calibration is developed that can be used to determine the camera calibration parameters, including those describing lens distortion, from a single image. Combined with the DLT method, this method allows a rapid and comprehensive in-situ camera calibration and therefore is particularly useful for quantitative flow visualization and other measurements such as model attitude and deformation in production wind tunnels. The paper also includes a brief description of typical photogrammetric applications to temperature- and pressure-sensitive paint measurements and model deformation measurements in wind tunnels.

Liu, Tian-Shu↗
NASA NTRS2003

Visualization experiences and issues in Deep Space Exploration

The panelists will discuss their experiences in collecting data in deep space, transmitting it to Earth, processing and visualizing it here, and using the visualization to drive the continued mission. This closes the loop, making missions more responsive to their environment, particularly in-situ operations on planetary surfaces and within planetary atmospheres.

visualization↗
NASA NTRS2005

The Mars Exploration Rover Instrument Positioning System

During Mars Exploration Rover (MER) surface operations, the scientific data gathered by the in situ instrument suite has been invaluable with respect to the discovery of a significant water history at Meridiani Planum and the hint of water processes at work in Gusev Crater. Specifically, the ability to perform precision manipulation from a mobile platform (i.e., mobile manipulation) has been a critical part of the successful operation of Spirit and Opportunity rovers. As such, this paper describes the MER Instrument Positioning System that allows the in situ instruments to operate and collect their important science data using a robust, dexterous robotic arm combined with visual target selection and autonomous software functions.

in situ instruments↗
NASA NTRS2022

In Situ Measurements of Surface Texture with Virtual Environments Support Science-Driven Human Surface Operations on the Moon and Beyond

Visualization tools enabling real-time scientific analysis are important for supporting future astronaut operations on the lunar surface. Such tools can be built into virtual environments to support scientific investigations, as well as situational awareness, real-time decision making, and efficient communication between astronauts and ground and support systems. Understanding how these tools can be optimized for science is essential for upcoming Artemis missions. In this contribution, we discuss how measurements of surface texture at multiple length scales can greatly enhance in situ science on/of the Moon, and eventually Mars, asteroids, and beyond. Roughness measurements at various wavelengths directly support objectives defined in the Artemis Science Plan, including (O1) “understanding planetary processes,” (O2) “understanding volatile cycles,” and (O3) “interpreting the impact history of the Earth-Moon system” . Key scientific analyses enabled by texture measurements at different length scales include: ● Sub-centimeter scales: Texture measurements can help constrain lava flow crystallinity, lava rheology, emplacement flow dynamics, and cooling histories (O1). Measurements of lacunarity (voids in fractal fill space) can shed light on eruptive volatile content, residence time of migrating volatiles, and near-surface volume available for micro-cold trapping of volatiles (O1, O2). ● Centimeter–meter scales: Texture measurements can be used for the differentiation of individual lava flows, the reconstruction of local stratigraphies and emplacement sequences, characterization of post-emplacement surface modification processes (O1, O3). Derived roughness (polarization) metrics can be used in the detection of water ice and characterization of ice properties (e.g., purity, grade, depth, abundance). ● Hectometer–Kilometer scales: Texture measurements can be used to differentiate major geologic surface units and surface structures (O1), constrain the presence of abundant ground ices (O2), and analyze surface modification and estimate surface age (O3). Real-time measurements of surface texture across these multiple length scales will enable efficient sample identification and scientific investigations by future astronauts. To support these investigations and the objective classification of surface texture, virtual environments employed by astronauts should be able to instantaneously convert raw data into processed data (e.g., digital terrain and elevation models) and derived metrics (e.g., RMS, std, Hurst, CPR) and perform statistical analyses (e.g., PCA, outliers, correlation matrices). Such tools are being developed and tested by the Resource Exploration and Science of our Cosmic Environment (RESOURCE) team, a node of NASA’s Solar System Exploration Research Virtual Institute (SSERVI), and are an excellent example of the powerful synergies of human and robotic ground assets critical in the return of humans to the Moon.

Ariel N. Deutsch↗
NASA NTRS1990

Multipoint observations of a small substorm

Results are presented of multipoint observations of a small substorm which occurred at about 0110 UT on April 25, 1985, carried out by AMPTE CCE, AMPTE IRM, DMSP F6, and DMSP F7, as well as by ground auroral stations and midlatitude stations. These data yield information on the latitudinal extent of the polar cap and provide visual identification of substorm aurorae, magnetic perturbations produced directly beneath aurorae, and the situ magnetic field. In addition, they provide magnetic-particle observations of the disruption of the cross-tail current sheet and observations concerning the spatial expansion of the current disruption region. Evidence is presented that the current sheet disruption observed by CCE in the neutral sheet was located on field lines which mapped to the westward traveling surge observed directly overhead of the ground station at Syowa.

Lopez, R. E.↗
NASA NTRS2017

Development and Assessment of the SMAP Enhanced Passive Soil Moisture Product

Launched in January 2015, the National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) observatory was designed to provide frequent global mapping of high-resolution soil moisture and freeze-thaw state every two to three days using a radar and a radiometer operating at L-band frequencies. Despite a hardware mishap that rendered the radar inoperable shortly after launch, the radiometer continues to operate nominally, returning more than two years of science data that have helped to improve existing hydrological applications and foster new ones.Beginning in late 2016 the SMAP project launched a suite of new data products with the objective of recovering some high-resolution observation capability loss resulting from the radar malfunction. Among these new data products are the SMAP Enhanced Passive Soil Moisture Product that was released in December 2016, followed by the SMAPSentinel-1 Active-Passive Soil Moisture Product in April 2017.This article covers the development and assessment of the SMAP Level 2 Enhanced Passive Soil Moisture Product (L2_SM_P_E). The product distinguishes itself from the current SMAP Level 2 Passive Soil Moisture Product (L2_SM_P) in that the soil moisture retrieval is posted on a 9 km grid instead of a 36 km grid. This is made possible by first applying the Backus-Gilbert optimal interpolation technique to the antenna temperature (TA) data in the original SMAP Level 1B Brightness Temperature Product to take advantage of the overlapped radiometer footprints on orbit. The resulting interpolated TA data then go through various correctioncalibration procedures to become the SMAP Level 1C Enhanced Brightness Temperature Product (L1C_TB_E). The L1C_TB_E product, posted on a 9 km grid, is then used as the primary input to the current operational SMAP baseline soil moisture retrieval algorithm to produce L2_SM_P_E as the final output. Images of the new product reveal enhanced visual features that are not apparent in the standard product. Based on in situ data from core validation sites and sparse networks representing different seasons and biomes all over the world, comparisons between L2_SM_P_E and in situ data were performed for the duration of April 1, 2015 October 30, 2016. It was found that the performance of the enhanced 9 km L2_SM_P_E is equivalent to that of the standard 36 km L2_SM_P, attaining a retrieval uncertainty below 0.040 m(exp 3)/m(exp 3) unbiased root-mean-square error (ubRMSE) and a correlation coefficient above 0.800. This assessment also affirmed that the Single Channel Algorithm using the V-polarized TB channel (SCA-V) delivered the best retrieval performance among the various algorithms implemented for L2_SM_P_E, a result similar to a previous assessment for L2_SM_P.

Enhanced↗
NASA NTRS2024

Central California Disasters: Incorporating Satellite-Derived Precipitation and Soil Moisture Products into Flood Preparedness and Emergency Management in California

Atmospheric rivers are a major contributor to extreme precipitation events and flooding in California. This study assessed the feasibility of using Earth observation data to monitor precipitation, soil moisture, and flooding from atmospheric rivers in the Salinas River Watershed in central California during the winter of 2022-2023. The team analyzed satellite derived precipitation estimates from the Global Precipitation Measurement mission, soil moisture data from the Soil Moisture Active Passive radiometer, and synthetic aperture radar imagery from Sentinel-1 to detect flood inundation. Global Precipitation Measurement precipitation estimates were found to underestimate rainfall by 33% to 52% compared to rain gauge data. The team found the Soil Moisture Active Passive dataset to be a valuable flooding indicator that they could visualize through various graphical representations, although its accuracy still needs verification with in situ flood maps. Sentinel-1 synthetic aperture radar imagery provided mapping of flood inundation extent along the Salinas River and surrounding areas and the Blue Spot model appears to be a good predictor of pluvial flood zones. The findings suggest Earth observations can enhance precipitation and flooding monitoring by the California Department of Water Resources, though further verification is needed. Integration of these datasets with vulnerability indices highlighted communities at highest risk during the 2022-2023 flooding events.

Abhinav Banthiya↗
NASA NTRS2014

NASA Giovanni: A Tool for Visualizing, Analyzing, and Inter-comparing Soil Moisture Data

There are many existing satellite soil moisture algorithms and their derived data products, but there is no simple way for a user to inter-compare the products or analyze them together with other related data. An environment that facilitates such inter-comparison and analysis would be useful for validation of satellite soil moisture retrievals against in situ data and for determining the relationships between different soil moisture products. As part of the NASA Giovanni (Geospatial Interactive Online Visualization ANd aNalysis Infrastructure) family of portals, which has provided users worldwide with a simple but powerful way to explore NASA data, a beta prototype Giovanni Inter-comparison of Soil Moisture Products portal has been developed. A number of soil moisture data products are currently included in the prototype portal. More will be added, based on user requirements and feedback and as resources become available. Two application examples for the portal are provided. The NASA Giovanni Soil Moisture portal is versatile and extensible, with many possible uses, for research and applications, as well as for the education community.

soil moisture data↗
NASA NTRS1989

Phylogenetic perspective and the search for life on earth and elsewhere

Any search for microbial life on Mars cannot rely upon cultivation of indigenous organisms. Only a minority of even terrestrial organisms that are observed in mixed, naturally-occurring microbial populations can be cultivated in the laboratory. Consequently, methods are being developed for analyzing the phylogenetic affiliations of the constituents of natural microbial populations without the need for their cultivation. This is more than an exercise in taxonomy, for the extent of phylogenetic relatedness between unknown and known organisms is some measure of the extent of their biochemical commonalities. In one approach, total DNA is isolated from natural microbial populations and 16S rRNA genes are shotgun cloned for rapid sequence determinations and phylogenetic analyses. A second approach employs oligodeoxynucleotide hybridization probes that bind to phylogenetic group-specific sequences in 16S rRNA. Since each actively growing cell contains about 104 ribosomes, the binding of the diagnostic probes to single cells can be visualized by radioactivity or fluorescence. The application of these methods and the use of in situ cultivation techniques is illustrated using submarine hydrothermal vent communities. Recommendations are made regarding planning toward future Mars missions.

Pace, Norman R.↗
NASA NTRS1991

Development of a figure-of-merit for space missions

The concept of a quantitative figure-of-merit (FOM) to evaluate different and competing options for space missions is further developed. Over six hundred individual factors are considered. These range from mission orbital mechanics to in-situ resource utilization (ISRU/ISMU) plants. The program utilizes a commercial software package for synthesis and visual display; the details are completely developed in-house. Historical FOM's are derived for successful space missions such as the Surveyor, Voyager, Apollo, etc. A cost FOM is also mentioned. The bulk of this work is devoted to one specific example of Mars Sample Return (MSR). The program is flexible enough to accommodate a variety of evolving technologies. Initial results show that the FOM for sample return is a function of the mass returned to LEO, and that missions utilizing ISRU/ISMU are far more cost effective than those that rely on all earth-transported resources.

Preiss, Bruce↗
NASA NTRS2003

Laboratory and In-Flight In-Situ X-ray Imaging and Scattering Facility for Materials, Biotechnology and Life Sciences

We propose a multifunctional X-ray facility for the Materials, Biotechnology and Life Sciences Programs to visualize formation and behavior dynamics of materials, biomaterials, and living organisms, tissues and cells. The facility will combine X-ray topography, phase micro-imaging and scattering capabilities with sample units installed on the goniometer. This should allow, for the first time, to monitor under well defined conditions, in situ, in real time: creation of imperfections during growth of semiconductors, metal, dielectric and biomacromolecular crystals and films, high-precision diffraction from crystals within a wide range of temperatures and vapor, melt, solution conditions, internal morphology and changes in living organisms, tissues and cells, diffraction on biominerals, nanotubes and particles, radiation damage, also under controlled formation/life conditions. The system will include an ultrabright X-ray source, X-ray mirror, monochromator, image-recording unit, detectors, and multipurpose diffractometer that fully accommodate and integrate furnaces and samples with other experimental environments. The easily adjustable laboratory and flight versions will allow monitoring processes under terrestrial and microgravity conditions. The flight version can be made available using a microsource combined with multilayer or capillary optics.

Source record↗
NASA NTRS2017

The Importance of Earth Observations and Data Collaboration within Environmental Intelligence Supporting Arctic Research

Within the IARPC Collaboration Team activities of 2016, Arctic in-situ and remote earth observations advanced topics such as :1) exploring the role for new and innovative autonomous observing technologies in the Arctic; 2) advancing catalytic national and international community based observing efforts in support of the National Strategy for the Arctic Region; and 3) enhancing the use of discovery tools for observing system collaboration such as the U.S. National Oceanic and Atmospheric Administration (NOAA) Arctic Environmental Response Management Application (ERMA) and the U.S. National Aeronautics and Space Administration (NASA) Arctic Collaborative Environment (ACE) project geo reference visualization decision support and exploitation internet based tools. Critical to the success of these earth observations for both in-situ and remote systems is the emerging of new and innovative data collection technologies and comprehensive modeling as well as enhanced communications and cyber infrastructure capabilities which effectively assimilate and dissemination many environmental intelligence products in a timely manner. The Arctic Collaborative Environment (ACE) project is well positioned to greatly enhance user capabilities for accessing, organizing, visualizing, sharing and producing collaborative knowledge for the Arctic.

Casas, Joseph↗
NASA NTRS1996

Real-Time Visualization of an HPF-based CFD Simulation

Current time-dependent CFD simulations produce very large multi-dimensional data sets at each time step. The visual analysis of computational results are traditionally performed by post processing the static data on graphics workstations. We present results from an alternate approach in which we analyze the simulation data in situ on each processing node at the time of simulation. The locally analyzed results, usually more economical and in a reduced form, are then combined and sent back for visualization on a graphics workstation.

Kremenetsky, Mark↗