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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.

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NASA NTRS1985

Scientific requirements for a Moderate-Resolution Imaging Spectrometer (MODIS) for EOS

The MODIS is an instrument planned for the sun-synchronous polar orbiting segment of the Space Station system. The radiometer is required to have 1 km resolution in terrestrial remote sensing applications. The monitoring program is targeted to last 10 yr in order to provide a sufficient database for discerning trends as opposed to natural variations. The study areas of interest include tropical deforestation, regrowth and areal distributions, acid rain effects on northern forests, desertification rates and locations, snow cover/albedo relationships and total biomass. MODIS will have 192 channels with 30 m spatial resolution and cover seven bands in the 3.5-12 microns interval for land viewing. Ocean studies will be carried out in 17 bands from 0.4-1.0 micron, and atmospheric scans will be performed over the land and ocean intervals at narrowband wavelengths (1.2 nm). Si detector arrays will be used and will be accompanied by an expected 600:1 SNR and produce data at a rate of 1.4-9.1 Mb/sec.

Barnes, W. L.↗

NASA NTRS1990

Earth Observing System instrument performance - Moderate Resolution Imaging Spectrometer case study

The requirements for characterization and calibration of instruments for the Earth Observing System space segment are defined in terms of tracking the Level 1 data for a sensor. The data must be traceable over the 15 year program, and must provide corrections for radiometric, spectral and geometric coefficients which capture the combined design and performance characteristics of the sensor. These requirements are then developed for MODIS-N to identify a set of techniques which can be used in the laboratory, spacecraft integrator's facility and in-orbit. The in-orbit of the so-called reflectance and radiance methods are reviewed, and the cross-calibrations available between HIRIS and MODIS through these techniques are listed. A scheme for the use of all available tools for instrument performance is provided as a Figure showing an estimated time interval over which each tool is expected to be useful. The final calibration strategy and plan must be developed through the understanding of a useful strategy for each of these candidate mechanisms.

Guenther, Bruce W.↗

DOE OSTI2016

Semiautomated segmentation of head and neck cancers in 18F-FDG PET scans: A just-enough-interaction approach

Purpose: The purpose of this work was to develop, validate, and compare a highly computer-aided method for the segmentation of hot lesions in head and neck 18F-FDG PET scans. Methods: A semiautomated segmentation method was developed, which transforms the segmentation problem into a graph-based optimization problem. For this purpose, a graph structure around a user-provided approximate lesion centerpoint is constructed and a suitable cost function is derived based on local image statistics. To handle frequently occurring situations that are ambiguous (e.g., lesions adjacent to each other versus lesion with inhomogeneous uptake), several segmentation modes are introduced that adapt the behavior of the base algorithm accordingly. In addition, the authors present approaches for the efficient interactive local and global refinement of initial segmentations that are based on the “just-enough-interaction” principle. For method validation, 60 PET/CT scans from 59 different subjects with 230 head and neck lesions were utilized. All patients had squamous cell carcinoma of the head and neck. A detailed comparison with the current clinically relevant standard manual segmentation approach was performed based on 2760 segmentations produced by three experts. Results: Segmentation accuracy measured by the Dice coefficient of the proposed semiautomated and standard manual segmentation approach was 0.766 and 0.764, respectively. This difference was not statistically significant (p = 0.2145). However, the intra- and interoperator standard deviations were significantly lower for the semiautomated method. In addition, the proposed method was found to be significantly faster and resulted in significantly higher intra- and interoperator segmentation agreement when compared to the manual segmentation approach. Conclusions: Lack of consistency in tumor definition is a critical barrier for radiation treatment targeting as well as for response assessment in clinical trials and in clinical oncology decision-making. The properties of the authors approach make it well suited for applications in image-guided radiation oncology, response assessment, or treatment outcome prediction.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Outer Wall Segmentation of Abdominal Aortic Aneurysm by Variable Neighborhood Search Through Intensity and Gradient Spaces

Aortic aneurysm segmentation remains a challenge. Manual segmentation is a time-consuming process which is not practical for routine use. To address this limitation, several automated segmentation techniques for aortic aneurysm have been developed, such as edge detection-based methods, partial differential equation methods, and graph partitioning methods. However, automatic segmentation of aortic aneurysm is difficult due to high pixel similarity to adjacent tissue and a lack of color information in the medical image, preventing previous work from being applicable to difficult cases. This paper uses uses a variable neighborhood search that alternates between intensity-based and gradient-based segmentation techniques. By alternating between intensity and gradient spaces, the search can escape from local optima of each space. The experimental results demonstrate that the proposed method outperforms the other existing segmentation methods in the literature, based on measurements of dice similarity coefficient and jaccard similarity coefficient at the pixel level. In addition, it is shown to perform well for cases that are difficult to segment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2024

Stellar Population Properties in the Stellar Streams around SPRC047

Abstract We have investigated the properties (e.g., age, metallicity) of the stellar populations of a ringlike tidal stellar stream (or streams) around the edge-on galaxy SPRC047 (z= 0.031) using spectral energy distribution (SED) fits to integrated broadband aperture flux densities. We used visual images in six different bands and Spitzer/IRAC 3.6μm data. We have attempted to derive best-fit stellar population parameters (metallicity, age) in three noncontiguous segments of the stream. Due to the very low surface brightness of the stream, we have performed a deconvolution with a Richardson–Lucy–type algorithm of the low spatial resolution 3.6μm IRAC image, thereby reducing the effect of the point-spread function aliasedemissionfrom the bright edge-on central galaxy at the locations of our three stream segments. Our SED fits that used several different star formation (SF) history priors, from an exponentially decaying SF burst to continuous SF, indicate that the age–metallicity–dust degeneracy is not resolved, most likely because of inadequate wavelength coverage and low signal-to-noise ratios of the low surface brightness features. We also discuss how future deep visual–near-infrared observations, combined with absolute flux calibration uncertainties at or below the 1% level, complemented by equally well absolute flux-calibrated observations in ultraviolet and mid-infrared bands, would improve the accuracy of broadband SED fitting results for low surface brightness targets, such as stellar streams around nearby galaxies that are not resolved into stars.

Astronomy & Astrophysics↗

NASA NTRS1994

Segmentation Of Multifrequency Complex-Amplitude SAR Data

Several mathematical models and associated algorithms implement method of segmenting multifrequency, highly speckled, high-resolution, complex-amplitude (amplitude and phase) synthetic-aperture-radar (SAR) digitized image into regions, within each of which radar backscattering characteristics are similar or homogeneous from place to place. Typically, each region represents different type of terrain or other surface; e.g., forest, agricultural land, sea ice, or water. Method of segmentation of SAR scene into regions is product of generalization, to multifrequency case, of single-frequency method described in "Algorithms for Segmentation of Complex-Amplitude SAR Data" (NPO-18524).

Rignot, Eric J.↗

DOE OSTI2012

Origins of Feeding Arteries of Hepatocellular Carcinoma Located Near the Umbilical Fissure of the Left Hepatic Lobe: Angiographic Evaluation

Purpose: To analyze the origins of the feeding arteries of hepatocellular carcinomas (HCCs) near the umbilical fissure of the left hepatic lobe. Methods: Twenty-eight HCCs with a mean {+-} SD tumor diameter of 3.4 {+-} 1.0 cm (range 1-4.4 cm) in contact with the right or left side of the umbilical fissure were treated by superselective transcatheter arterial chemoembolization (TACE). The origins of the tumor-feeding arteries were analyzed with arteriograms and computed tomography or cone-beam computed tomography images obtained during and 1 week after TACE.ResultsTwenty-one HCC lesions were located in segment 3 and seven were located in segment 4. Of 21 tumors in segment 3, 13 (61.9%) were supplied by the lateral inferior subsegmental artery (A3), three (14.3%) by the medial subsegmental artery (A4), three (14.3%) by both A4 and A3, one (4.8%) by a branch arising from the left lateral hepatic artery, and one (4.8%) by a branch of the right gastric artery. In particular, all tumor-feeding branches arising from A4 were the first branch of A4. Of seven tumors in segment 4, four (57.1%) were supplied by A4 and three (42.9%) by A3. In particular, all tumor-feeding branches arising from A3 were the first branch of A3. Conclusion: This study demonstrates crossover blood supply to HCC lesions located near the umbilical fissure, in addition to direct feeding from a separate branch. In particular, the first branch of the opposite subsegmental artery may feed tumors when crossover blood supply is present.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2021

Electrospinning Induced Orientation of Protein Fibrils

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99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2025

Evolution of intermittent filaments in the scrape-off layer of NSTX

Filamentary structures naturally arise from background turbulence in the scrape-off layer (SOL) of plasmas, leading to significant particle and heat transport that can degrade overall plasma confinement. This enhanced transport can contribute to unacceptably high heat loads on plasma-facing components. As such, understanding the physics of SOL plasma filaments is critical for predicting and mitigating their effects in future fusion devices. On the National Spherical Torus Experiment (NSTX), plasma filaments—commonly referred to as “blobs”—were investigated using the gas-puff imaging (GPI) diagnostic in the edge and SOL regions. The analysis involved identifying, segmenting, and tracking the characteristic contours of the blobs in each frame of the GPI video sequences. Their evolution was characterized through shape descriptors, velocity, and angular velocity derived from their contour coordinates. The results indicate that as the blob area increases, their shapes become more concave and less circular, suggesting reduced structural stability in larger blobs. This result aligns with previous theoretical results where it was shown that larger blobs are more susceptible to instabilities [Krasheninnikov et al., J. Plasma Phys. 74, 679–717 (2008) and D'Ippolito et al., Phys. Plasmas 18, 060501 (2011)]. A positive correlation was observed between radial velocity and radial position, suggesting radially outward acceleration of the filaments, potentially driven by decreasing viscous drag toward the far SOL. Interestingly, blobs in background SOL turbulence exhibited minimal spinning in contrast to filaments originating from edge localized modes, which show substantial rotation during their paths [Lampert et al., Phys. Plasmas 29, 102502 (2022)]. Statistical analysis of the solidity and total curvature shape descriptors, along with their temporal evolution, revealed relatively broad, near-Gaussian distributions. This suggests that blob morphology is strongly influenced by stochastic turbulent processes in the surrounding plasma environment. Blob parameters were also compared with bulk plasma and radial profile measurements. Notable trends were found between blob rotation and poloidal velocity with collisionality and line-integrated density. These findings contribute to a deeper understanding of blob dynamics and provide valuable insights for refining SOL turbulence models.

Covariance and correlation↗

DOE OSTI2026

Particle trajectory representation learning with masked point modeling

Liquid argon time projection chambers (LArTPCs) offer millimeter-scale 3D images of particle trajectories, enabling precision studies of neutrino oscillation, detection of supernova and solar neutrinos, searches for exotic dark matter, and proton decay. Current approaches utilize supervised machine learning models, requiring extensive simulations of particle physics and detector response that can introduce bias. Self-supervised learning (SSL), a machine learning approach that learns useful representations of unlabeled data from the data itself, has significantly advanced how large datasets are utilized for representation learning; however, its potential for applications to sensory data in high precision particle physics experiments remains largely unexplored. We introduce the Point-based liquid argon masked autoencoder (PoLAr-MAE), a self-supervised framework that learns physically meaningful representations directly from unlabeled LArTPC images. PoLAr-MAE achieves remarkable data efficiency for a point-level segmentation task, outperforming fully supervised methods in low data regimes. Linear classifiers on model outputs demonstrate robust performance across multiple downstream tasks. Our results position sensor-level SSL as a practical foundation model strategy for LArTPCs.

Young, Samuel [Stanford Univ., CA (United States)]↗

DOE OSTI2025

ecospec v0.1.0

Bespoke software for segmenting plants in ecoFABs to monitor growth and health. Contains python libraries for image alignment, training neural networks and running inference.

Zwart, PetrusH [Lawrence Berkeley National Laborat↗

DOE OSTI2015

SE Great Basin Play Fairway Analysis Heat and Permeability CRS

Within this submission are multiple .tif images with accompanying metadata of magnetotelluric conductor occurrence, fault critical stress composite risk segment (CRS), permeability CRS, Quaternary mafic extrusions, Quaternary fault density, and Quaternary rhyolite maps. Each of these contributed to a final play fairway analysis (PFA) for the SE Great Basin study area.

15 GEOTHERMAL ENERGY↗

NASA NTRS1984

Texture classification using autoregressive filtering

A general theory of image texture models is proposed and its applicability to the problem of scene segmentation using texture classification is discussed. An algorithm, based on half-plane autoregressive filtering, which optimally utilizes second order statistics to discriminate between texture classes represented by arbitrary wide sense stationary random fields is described. Empirical results of applying this algorithm to natural and sysnthesized scenes are presented and future research is outlined.

Lawton, W. M.↗

NASA NTRS1992

Encoding spatial images: A fuzzy set theory approach

As the use of fuzzy set theory continues to grow, there is an increased need for methodologies and formalisms to manipulate obtained fuzzy subsets. Concepts involving relative position of fuzzy patterns are acknowledged as being of high importance in many areas. In this paper, we present an approach based on the concept of dominance in fuzzy set theory for modelling relative positions among fuzzy subsets of a plane. In particular, we define the following spatial relations: to the left (right), in front of, behind, above, below, near, far from, and touching. This concept has been implemented to define spatial relationships among fuzzy subsets of the image plane. Spatial relationships based on fuzzy set theory, coupled with a fuzzy segmentation, should therefore yield realistic results in scene understanding.

Sztandera, Leszek M.↗

NASA NTRS1994

Mars Pathfinder: Landing Site Computer Animation [and] Rocky IV

This video uses computer graphic models of the heat shield, lander, and parachute to present an artist's concept of the Mars Pathfinder descent. Viking image mosaics are used to create a rotating globe of Mars. A separate segment presents a simulated flight over the Mars Pathfinder landing site. The second part of the film describes the development of Rocky IV, the latest in a series of planetary rovers developed in preparation for the Mars Pathfinder mission.

Source record↗

NASA NTRS2002

Ultralightweight Space Deployable Primary Reflector Demonstrator

A concept has been developed and analyzed and several generational prototypes built for a gossamer-class deployable truss for a mirror or reflector with many smaller precisely-figured solid elements attached will, for at least the next several decades, minimize the mass of a large primary mirror assembly while still providing the high image quality essential for planet-finding and cosmological astronomical missions. Primary mirror segments are mounted in turn on ultralightweight thermally-formed plastic panels that hold clusters of mirror segments in rigid arrays whose tip/tilt and piston would be corrected over the scale of the plastic panels by the control segments. Prototype panels developed under this program are 45 cm wide and fabricated from commercially available Kaplan sheets. A three-strut octahedral tensegrity is the basis for the overall support structure. Each fundamental is composed of two such octahedrons, rotated oppositely about a common triangular face. Adjacent modules are joined at the nodes of the upper and lower triangles to form a deployable structure that could be made arbitrarily large. A seven-module dowel-and-wire prototype has been constructed. Deployment techniques based on the use of collapsing toggled struts with diagonal tensional elements allows an assembly of tensegrities to be fully collapsed and redeployed. The prototype designs will be described and results of a test program for measuring strength and deformation will be presented.

Montgomery, Edward E., IV↗

NASA NTRS1991

High speed multiwire photon camera

An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occuring during the readout window.

Lacy, Jeffrey L.↗

NASA NTRS1989

High speed multiwire photon camera

Lacy, Jeffrey L.↗