Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “MT data”

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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Radar stereomapping techniques and application to SIR-B images of Mt. Shasta

One of the goals of the SIR-B experiment was the definition of optimum radar incidence and intersection angles for radargrammetric stereoscopy by comparing the results from three separate data-reduction methods. To this end three overlapping images of the prime radargrammetric site (Mt. Shasta in northern California) were obtained, fewer than anticipated. This paper describes the mathematical basis for radar stereomapping, along with preliminary results from one of the methods (using a so-called 'analytical' stereoplotter) for the Mt. Shasta site. Height coordinate errors range from 60 to 170 m depending on the density (number per ground area) of ground control points used.

Leberl, F. W.↗
NASA NTRS1988

Clockwise rotation of the western Mojave Desert

A study of paleomagnetic data from Miocene volcanic rocks in the western Mojave Desert, which suggests about 25 deg of clockwise rotation, is presented. A total of 166 oriented core samples of two types of basalt were taken from 19 sites in the region. After demagnetization to 40 or 60 mT, application of structural corrections, and inversion of reversed sites, the data yielded an average direction of 51.6 deg inclination and 15.6 deg declination. When compared with the expected direction for Miocene rocks for stable North America, the direction for these Mojave rocks shows a clockwise rotation of 23.8 deg + or - 11.3 deg and a flattening of about 2.1 deg, a rotation which agrees in direction with oroclinal bending of the southern Sierra Nevada due to right-lateral shear along the western margin of North America. Most of this rotation is constrained by other paleomagnetic and strucural information to have occurred soon after the sampled basalts were deposited (about 20 Ma) and before about 16 Ma. These clockwise declination anomalies indicate that any subsequent counterclockwise rotation is small and/or compensated by previous clockwise rotation.

Golombek, Matthew P.↗
NASA NTRS1990

Multiple strike slip faults sets: A case study from the Dead Sea transform

In many strike slip tectonic settings, large rotations of crust blocks about vertical axes have been inferred from paleomagnetic data. These blocks are bounded by sets of parallel faults which presumably accommodate the relative motion between the blocks as regional deformation progress. A mechanical model by Nur et al., (1986) suggests that rotations greater than phi sub c equals 25 to 45 degrees must be accommodated by more than one set of faults, with angle phi sub c between their direction; consequently the sum of the angles between sets must be roughly equal to the total tectonic material rotation. To test this model, the authors investigated the fault geometry and field relation of fault sets in the Mt. Hermon area in northern Israel, where paleomagnetic declination implies data 69 degrees plus or minus 13 degrees counter-clockwise block rotation. The statistical and field relation analysis of over 315 faults shows that the faulting is predominantly right lateral strike slip consisting of three distinct sets. The oldest set strikes 253 degrees, the second oldest set strikes 293 degrees and the youngest strikes 339 degrees. This last direction is consistent also with the current north-south direction of the maximum principle stress axis. The angle phi sub c between the first and second sets is 39 degrees and between the second and third sets 46 degrees, in good agreement with the phi sub c angle predicted from mechanical considerations. The sum of the two angles is 85 degrees, in good agreement with the 69 degrees plus or minus 13 degrees CCW paleomagnetically derived rotation. The results suggest specifically that the sequential development of multiple intersecting fault sets is responsible for the faulting in the Mt. Hermon area; and generally that the model of block rotation with multiple faults provides very good simple rules for analyzing very complex fault patterns.

Ron, Hagai↗
DOE OSTI2022

Context matters: Natural tree mortality can lead to neighbor growth release or suppression

Where competition suppresses tree growth, mortality of adjacent trees can release the surviving individuals, leading to a growth increase. However, primary forests are complicated systems, where trees interact in both competitive and facilitative ways mediated by their size, species, and the broad ecological context in which they grow. Thus, the magnitude and even direction of growth responses to the mortality of nearby trees may vary, which has implications for our understanding of community- and ecosystem-level dynamics following mortality events. Unfortunately, although many studies focus on the impacts of light availability and general crowding on tree growth, we know relatively little about the effects of naturally occurring mortality events on the growth of neighboring trees. To address this issue, we used 40 years of data from 15 permanent forest-monitoring plots in Mt Rainier old-growth forests, comparing observed to expected radial growth of individual trees following the death of their nearest neighbor. Although we found evidence of a general growth-release response, this was not universal among all trees, with small trees in particular exhibiting growth suppression (rather than release) following neighboring tree mortality. In addition to small size, growth-suppression was more likely if the dead neighbor was the same species, consistent with facilitative effects as mediated through belowground networks. At the stand level, the average growth release after nearest neighbor mortality was greatest in low-density stands with large trees, with elevation and community composition also playing a role. Decades more monitoring could reveal how long growth release (or suppression) is sustained by individual trees following neighboring mortality events, as well as potential response lags and the role of species identity in determining whether interactions with neighbors are competitive or facilitative. Nonetheless, our results suggest that although mature trees have competitive effects on their larger neighbors, they also have an important role in supporting the ingrowth of small trees. More broadly, we demonstrate that the nature of interactions between individual neighboring trees is highly context dependent.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1985

Geologic results of the TMS survey over Mt. Emmons, Colorado

In 1981, NASA conducted with an American company a cooperative study, involving the use of Thematic Mapper Simulator (TMS) data. The study was concerned with an area near Crested Butte, Colorado, which contains a known, but unmined, major molybdenum deposit. Detailed ground observations in the Mt. Emmons area demonstrated that the imagery was extremely effective for detection of geologically significant features. The imagery specifically delineated areas of ferric iron staining, seritization, and hornfelized rock. Attention is given to data acquisition and data processing, field work in 1982 and in 1983, the integration of gravity data, and costs.

Rickman, D. L.↗
DOE OSTI2025

2025 TEM Workshop

The TEM Data Management Workshop will take place on August 26 from 9 a.m. to 12 p.m. MT, and will be held virtually on TEAMS. The primary goal of this workshop is to engage NSUF users and stakeholders in discussions about the data needs for the utilization of AI and ML in the analysis of TEM data. Key topics to be covered include data storage, data sharing, data tagging, metadata inclusion, standardized data formats, data augmentation, and annotated training datasets. Additionally, the workshop will provide valuable insights into resources such as the Nuclear Research Data System (NRDS) for data storage and sharing, as well as open-source codes for data analysis.

Bachhav, Mukesh↗
DOE OSTI2022

Kilauea Magnetotelluric Dataset

In 2002 and 2003 a collaborative effort was undertaken between Lawrence Berkeley National Laboratory, Sandia National Laboratories, the USGS Menlo Park, the USGS Hawaiian Volcano Observatory, and Electromagnetic Instruments Inc. to study the Kilauea volcano in Hawaii using the magnetotelluric (MT) technique. The work was motivated by a desire to improve understanding of the magma reservoirs and conduits within Kilauea and the East and Southwest Rift zones, which has implications for understanding Kilaueas plumbing system. An improved understanding of the rift zones has implications in understanding large-scale landslides that are generated in the Hilina Slump, which produce significant impacts on coastal communities. Up to eight stations operated simultaneously, with multiple remote reference sites, and data were processed using multi-station robust processing techniques. In total, data were acquired at 70 sites over the Southwest and East rift zones. Good to excellent quality data were obtained even in the harshest conditions, such as those encountered on the fresh lava flows of the East Rift Zone (ERZ), where electrical contact resistances are on the order of 100 kOhm. This data supports the continuing efforts to increase geothermal power on the island of Hawaii. Each of the 70 EDI files are the MT impedance tensors for 1 site. There is also a description of the processing of the data and a site map showing the locations of each site.

15 GEOTHERMAL ENERGY↗
NASA NTRSDate not supplied

Calculating the Height of Volcanic Cloud SO2 With a Lagrangian Trajectory Tool: Raikoke (2019) and Pinatubo (1991) Cases

We have developed a new data analysis tool to reconstruct the altitude of SO2 clouds ejected by avolcanic eruption. Starting with 2D fields of satellite observed SO2 column density, known volcanolocation, and reanalysis wind fields, the Goddard Lagrangian trajectory tool allows us to estimatethe altitude and local concentration of SO2 at the time of observation. We demonstrate this tool forthe June 21, 2019 Mt. Raikoke eruption (8h, 30h and 78 hours after eruption). We use SO2 data fromthe Ozone Mapping and Profiler Suite/Nadir Mapper (OMPS/NM) onboard the NASA-NOAASuomi National Polar Partnership satellite and the Tropospheric Monitoring Instrument(TROPOMI) onboard the European Copernicus Sentinel 5 precursor satellite and wind fields fromthe NASA Goddard Earth Observing System (GEOS) model. We obtained a wide distribution ofSO2 altitudes between 1 and 19 kilometers in different parts of the Raikoke SO2 clouds, with thehighest SO2 concentration between 11 and 16 km, in good agreement with data from independentSO2 layer height retrievals from TROPOMI and Infrared Atmospheric Sounding Interferometer(IASI). We then applied this method to the June 15, 1991 Mt. Pinatubo eruption using SO2 columnmeasurements from the NASA Total Ozone Mapping Spectrometer (TOMS) on June 16, 17, 18 andusing wind fields from the National Centers for Environmental Prediction Reanalysis version 2. Weobtained a wide distribution of SO2 heights from 6 km up to 30 km in the northern part of the cloud.We use our new trajectory tool to reconstruct volcanic SO2/aerosol emission sources as functions oftime and altitude, providing inputs to the GEOS model aerosol and chemistry schemes in order tosimulate the dispersion of volcanic SO2 and aerosol clouds from these events.

SO2↗
NASA NTRS1986

Characteristic recovery times of Forbush-type decreases in the cosmic radiation. I - Observations at earth at different energies

Data on 30 asymmetric Forbush decreases recorded by the IMP spacecraft at 1 AU and the Mt. Washington neutron monitor over the period 1972-84 are examined to characterize the recovery characteristics of cosmic rays after the events. The spacecraft data are concentrated at energies of 1.7 GV, while the terrestrial instruments recorded events at 5 GV. Attention is paid to the relative amplitudes of the recorded transient decreases, the characteristic recovery times, and the energy dependence of the amplitudes and recovery time. The recovery times were found to be equal at both energy levels, supporting a concept of energy independence for the recoveries. Also, no correlations were found between the recovery times and the occurrences of a solar magnetic field reversal or with phase in the solar modulation cycle. A time-dependent, two-dimensional model is defined, which expresses the cosmic ray particle distributions as a function of the decay of the disturbance, with a small dependence on the transport parameters of the cosmic rays.

Lockwood, J. A.↗
NASA NTRS1993

System services and architecture of the TMI satellite mobile data system

The North American Mobile Satellite Service (MSS) system being developed by AMSC/TMI and scheduled to go into service in early 1995 will include the provision for real time packet switched services (mobile data service - MDS) and circuit switched services (mobile telephony service - MTS). These services will utilize geostationary satellites which provide access to mobile terminals (MT's) through L-band beams. The MDS system utilizes a star topology with a centralized data hub (DH) and will support a large number of mobile terminals. The DH, which accesses the satellite via a single Ku band beam, is responsible for satellite resource management, for providing mobile users with access to public and private data networks, and for comprehensive network management of the system. This paper describes the various MDS services available for the users, the ground segment elements involved in the provisioning of these services, and a summary description of the channel types, protocol architecture, and network management capabilities provided within the system.

Gokhale, D.↗
NASA NTRS1994

PSC and volcanic aerosol routine observations in Antarctica by UV-visible ground-based spectrometry

Polar statospheric clouds (PSC) and stratospheric aerosol can be observed by ground-based UV-visible spectrometry by looking at the variation of the color of the sky during twilight. A radiative transfer model shows that reddenings are caused by high altitude (22-28 km) thin layers of scatterers, while low altitude (12-20 km) thick ones result in blueings. The color index method applied on 4 years of observations at Dumont d'Urville (67 deg S), from 1988 to 1991, shows that probably because the station is located at the edge of the vortex, dense PSC are uncommon. More unexpected is the existence of a systematic seasonal variation of the color of the twilight sky - bluer at spring - which reveals the formation of a dense scattering layer at or just above the tropopause at the end of the winter. Large scattering layers are reported above the station in 1991, first in August around 12-14 km, later in September at 22-24 km. They are attributed to volcanic aerosol from Mt Hudson and Mt Pinatubo respectively, which erupted in 1991. Inspection of the data shows that the lowest entered rapidly into the polar vortex but not the highest which remained outside, demonstrating that the vortex was isolated at 22-26 km.

Sarkissian, A.↗
DOE OSTI2022

Wabash CarbonSAFE Static and Dynamic Modeling: Task 9.0 (Technical Report)

The objective of the Wabash CarbonSAFE project’s static and dynamic modeling task is to assess the feasibility of storing 50 million tonnes (1.67 million metric tonnes annually; MMTA) of industrially-sourced carbon dioxide (CO 2 ) in a commercial-scale geological storage complex at Wabash Valley Resources LLC (WVR) gasification facility near Terre Haute, Indiana over a period of 30 years. The targeted formations for storing CO 2 are: 1) Mt. Simon Sandstone (MSS) and the 2) Potosi Dolomite (Knox Group). All of the available data from the recently drilled Wabash #1 stratigraphic test well (now plugged and abandoned) were used in the construction of both the static and dynamic models. Geologic models were constructed to characterize both the Mt. Simon Sandstone and Potosi Dolomite storage complexes. Dynamic simulation models were constructed and used to assess the feasibility of injecting CO 2 into the Mt. Simon and Potosi formations. The geocellular models for the Potosi Dolomite and Mt. Simon Sandstone were built using Petrel™, Schlumberger’s reservoir modeling software. The dynamic simulations were run using Landmark’s Nexus ® reservoir simulation software.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

Tracing the impacts of Mount Pinatubo eruption on regional climate using spatially-varying changepoint detection

Significant events, such as volcanic eruptions, can have global and long-lasting impacts on climate. These global impacts, however, are not uniform across space and time. Understanding how the Mt. Pinatubo eruption affects global and regional climate is of great interest for predicting the impact on climate due to similar events as well as understanding the possible effect of the stratospheric aerosol injections proposed to combat climate change. While many studies illustrated the impact of the Pinatubo eruption on a global scale, studies at a fine regional scale are scarce. Here, we propose a Bayesian spatially-varying changepoint detection and estimation method to trace the impact of Mt. Pinatubo eruption on regional climate. Our approach takes into account the diffusing nature and spatial correlation of the climate changes attributed to the volcanic eruption. We illustrate our method and demonstrate its advantages over an existing changepoint detection method through simulations. Finally, we apply our method to monthly stratospheric aerosol optical depth and surface temperature data from 1985 to 1995 to detect and estimate changepoints following the 1991 Mt. Pinatubo eruption. Our results quantitatively characterize the spatial pattern of the eruption’s impact on regional climate, complementing the previous studies on the global impact of the Pinatubo eruption.

Aerosol optical depth↗
NASA NTRS1986

Space Shuttle radargrammetry results

Preliminary results on the radargrammetric processing of SIR-A and SIR-B data are presented. Radargrammetric processing was applied to images of the Trinity National Forest in Northern California, the islands of Cephalonia, Ithaka, and Sardegna, Mt. Shasta, and Cordon La Grasa, Argentina. The preliminary processing of the SIR-A and SIR-B data has produced digital elevation models, stereo models, and a contour map.

Leberl, F.↗
DOE OSTI2025

Data-Efficient Strategies for Probabilistic Voltage Envelopes under Network Contingencies

This work presents an efficient data-driven method to construct probabilistic voltage envelopes (PVE) using power flow learning in grids with network contingencies. First, a network-aware Gaussian process (GP) termed Vertex-Degree Kernel (VDK-GP), developed in prior work, is used to estimate voltage–power functions for a few network configurations. The paper introduces a novel multi-task vertex degree kernel (MT-VDK) that amalgamates the learned VDK-GPs to determine power flows for unseen networks, with a significant reduction in the computational complexity and hyperparameter requirements compared to alternate approaches. Simulations on the IEEE 30-Bus network demonstrate the retention and transfer of power flow knowledge in both N-1 and N-2 contingency scenarios. The MT-VDK-GP approach achieves over 50 % reduction in mean prediction error for novel N-1 contingency network configurations in low training data regimes (50–250 samples) over VDK-GP. Additionally, MT-VDK-GP outperforms a hyper-parameter based transfer learning approach in over 75 % of N-2 contingency network structures, even without historical N-2 outage data. Furthermore, the proposed method demonstrates the ability to achieve PVEs using sixteen times fewer power flow solutions compared to Monte-Carlo sampling-based methods.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1973

Structural and lithologic study of northern coast ranges and Sacramento Valley, California

The author has identified the following significant results. The pattern of linear systems within the project area has been extended into the western foothill belt of the Sierra Nevada. The chief pattern of linear features in the western Sierran foothill belt trends about N. 10 - 15 deg W., but in the vicinity of the Feather River the trend of the features abruptly changes to about N. 50-60 deg W and appears to be contiguous across the Sacramento Valley with a similar system of linear features in the Coast Ranges. The linear features in the Modoc Plateau and Klamath Mt. areas appear unrelated to the systems detected in the Coast Ranges of Sierran foothill belt. Although the change in trend of the Sierran structural features has been previously suggested and the interrelationship of the Klamath Mt. region with the northern Sierra Nevadas has been postulated, the data obtained from the ERTS-1 imagery strengthens these notions and provides for the first time evidence of a direct connection of the structural trends within the alluviated part of the Sacramento Valley. In addition rocks of Pleistocene and Holocene age are offset by some of the linear features seen on ERTS-1 imagery and hence may record the latest episode of geologic deformation in north-central California.

Rich, E. I.↗
NASA NTRS2012

Observations and Models of the Lunar Sodium Exosphere 1988 - 1999

Sodium in the lunar exosphere is easily observed from the Earth's surface due to its strong resonance emission lines in the visible region of the spectrum. Although sodium is a trace element, it is easily ejected from the surface by a number of processes. The variation of this exospheric constituent both spatially and temporally can help to constrain these sources and the loss processes and their timescales. Due to a revival of interest in the Moon and its volatiles, observations of the lunar exosphere obtained at the McMath-Pierce solar telescope in 1998 and 1999 have recently been reduced and analyzed. In addition, observations of the lunar sodium exosphere obtained with the Mt. Lemmon Lunar Coronagraph on Mt. Lemmon, Arizona, have also been published. We combine these new data with data previously published and reanalyzed by Sarantos et al. This comprehensive data set will be modeled using both a simple Chamberlain exosphere model and a comprehensive Monte Carlo model.

Killen, Rosemary↗