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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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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Quantum Frequency Combs with Path Identity for Quantum Remote Sensing

Quantum sensing promises to revolutionize sensing applications by employing quantum states of light or matter as sensing probes. Photons are the clear choice as quantum probes for remote sensing because they can travel to and interact with a distant target. Existing schemes are mainly based on the quantum illumination framework, which requires quantum memory to store a single photon of an initially entangled pair until its twin reflects off a target and returns for final correlation measurements. Existing demonstrations are limited to tabletop experiments, and expanding the sensing range faces various roadblocks, including long-time quantum storage and photon loss and noise when transmitting quantum signals over long distances. We propose a novel quantum sensing framework that addresses these challenges using quantum frequency combs with path identity for remote sensing of signatures (“qCOMBPASS”). The combination of one key quantum phenomenon and two quantum resources—namely, quantum-induced coherence by path identity, quantum frequency combs, and two-mode squeezed light—allows for quantum remote sensing without requiring quantum memory. The proposed scheme is akin to a quantum radar based on entangled frequency-comb pairs that uses path identity to detect, range, or sense a remote target of interest by measuring pulses of one comb in the pair that never traveled to the target but that contains target information “teleported” by quantum-induced coherence by path identity from the other comb in the pair that traveled to the target but is not detected. We develop the basic qCOMBPASS theory, analyze the properties of the qCOMBPASS transceiver, and introduce the qCOMBPASS equation—a quantum analog of the well-known LIDAR equation in classical remote sensing. We also describe an experimental scheme to demonstrate the concept using two-mode squeezed quantum combs. qCOMBPASS can strongly impact various applications in remote quantum sensing, imaging, metrology, and communications. These applications include detection and ranging of low-reflectivity objects, measurement of small displacements of a remote target with precision beyond the standard quantum limit (SQL), standoff hyperspectral quantum imaging, discreet surveillance from space with low detection probability (detect without being detected), very-long-baseline interferometry, quantum Doppler sensing, quantum clock synchronization, and networks of distributed quantum sensors. Published by the American Physical Society 2024

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2024

Nonperturbative Zou-Wang-Mandel effect

The Zou-Wang-Mandel (ZWM) effect is a remarkable consequence of photon indistinguishability and continuous-variable entanglement in which an optical phase shift is imprinted on photonic modes associated with optical paths that that do not pass through the phase shift source. By bringing the canonical formalism of continuous-variable Gaussian states to bear on the mode-structure of the ZWM experiment, we show that the physical consequence of implementing optical path identity is a renormalization of quadrature squeezing which governs the entanglement of four effective optical modes. Nonperturbative expressions for the ZWM interference patterns and normalized first-order coherence function are derived. Generalizations to $\mathscr{H}$-graph states with more than four modes directly follow from the general method used to analyze the minimal example. Here, we show that a ZWM interferometer with a laser-seeded signal mode, which estimates an idler phase shift by detecting photons that did not propagate through the phase shift, exhibits an optimal sensitivity comparable to that of a laser-seeded SU(1,1) interferometer if path identity is implemented with high fidelity.

74 ATOMIC AND MOLECULAR PHYSICS↗
NASA NTRS1980

System for forming a quadrified image comprising angularly related fields of view of a three dimensional object

A system for generating, within a single frame of photographic film, a quadrified image including images of angularly (including orthogonally) related fields of view of a near field three dimensional object is described. It is characterized by three subsystems each of which includes a plurality of reflective surfaces for imaging a different field of view of the object at a different quadrant of the quadrified image. All of the subsystems have identical path lengths to the object photographed.

Chamberlain, F. R.↗
NASA NTRS1998

Airborne Laser Altimetric Monitoring of the Rapid Evolution of Topography in the Long Valley, CA, Caldera

A consortium of investigators from several universities and Government agencies have conducted a series of aircraft topographic surveys over the Long Valley caldera, California. The region has a geologic history of extensive volcanism, and its central dome has recently been undergoing resurgent uplift episodes of up to 4 cm per year, a deformation rate that is still continuing. These surveys were conducted from the NASA WFF T39 jet aircraft, outfitted with a nadir-profiling altimetric laser (ATLAS), a GPS guidance system for in-flight precision navigation, two P-code GPS receivers, a Litton LTN92 inertial unit for attitude determination, and both video and still-frame aerial cameras. In addition, two base-station GPS receivers were deployed for post-flight differential navigation, complementing the permanent GPS station operated on the resurgent dome by JPL, and a kinematic automobile survey of roads crossing the area was conducted, thereby complementing the JPL kinematic GPS surveys of some of the same roads. Precision flying yielded multiple profiles along nearly identical paths, including crossing profiles over selected locations within the caidera and calibration flights over Mono Lake, and Lake Crowley. Data from the most recent survey in 1995 are at this time still being reduced, but the standard error of the mean is very low (< 3 mm), due to the high number of crossover points. We thus intend to evaluate the technique for measuring systematic changes in the dome height over time.

Rundle, John↗
NASA NTRS2008

MISR Instrument Data Visualization

The MISR Interactive eXplorer (MINX) software functions both as a general-purpose tool to visualize Multiangle Imaging SpectroRadiometer (MISR) instrument data, and as a specialized tool to analyze properties of smoke, dust, and volcanic plumes. It includes high-level options to create map views of MISR orbit locations; scrollable, single-camera RGB (red-greenblue) images of MISR level 1B2 (L1B2) radiance data; and animations of the nine MISR camera images that provide a 3D perspective of the scenes that MISR has acquired. NASA Tech Briefs, September 2008 55 The plume height capability provides an accurate estimate of the injection height of plumes that is needed by air quality and climate modelers. MISR provides global high-quality stereo height information, and this program uses that information to perform detailed height retrievals of aerosol plumes. Users can interactively digitize smoke, dust, or volcanic plumes and automatically retrieve heights and winds, and can also archive MISR albedos and aerosol properties, as well as fire power and brightness temperatures associated with smoke plumes derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data. Some of the specialized options in MINX enable the user to do other tasks. Users can display plots of top-of-atmosphere bidirectional reflectance factors (BRFs) versus camera-angle for selected pixels. Images and animations can be saved to disk in various formats. Also, users can apply a geometric registration correction to warp camera images when the standard processing correction is inadequate. It is possible to difference the images of two MISR orbits that share a path (identical ground track), as well as to construct pseudo-color images by assigning different combinations of MISR channels (angle or spectral band) to the RGB display channels. This software is an interactive application written in IDL and compiled into an IDL Virtual Machine (VM) ".sav" file.

Nelson, David↗
NASA NTRS2024

Characterization of Low-Velocity Impact Damage in Toughened Non-Crimp Fabric Laminates

The damage response of resin-infused composites was investigated using quasi-static indentation (QSI) and instrumented drop-weight impact testing. The test specimens were composed of six layers of non-crimp fabrics where each layer contained +45°, 90°, −45°, and 0° plies. The goals of the testing were to identify damage responses that may differ from traditional thermoset materials and provide damage characterization data to evaluate current damage prediction analyses and aid improvements to current damage models. The damage was characterized using X-ray computed tomography (CT) and ultrasonic testing (UT). Incremental QSI loading was used on a single specimen to investigate damage growth in nine steps at progressively higher loads. Realtime acoustic emission data were used to determine the unloading points. Unlike typical thermoset composites, the force-displacement was smooth and showed no obvious indications of damage. The primary damage consisted of large lines of fiber fracture on the plies near the impact surface and delaminations through the thickness. Nine specimens were impacted at nominal impact energies of 25 ft-lbs, 30 ft-lbs, and 35 ft-lbs. The force histories at each energy followed nearly identical paths. Again, no obvious signs of damage were observed in any of the force histories. The general damage response in the dynamic tests was similar to the QSI-loaded specimens. However, repeat specimens impacted with a given impact energy showed variations in the damage. Some characteristics of the damage response were different than those typically observed in thermoset composites and will need to be evaluated using current analysis methods.

Composite Materials↗
NASA NTRSDate not supplied

Characterization of Low-Velocity Impact Damage in Toughened Non-Crimp Fabric Laminates

The damage response of resin-infused composites was investigated using quasi-static indentation (QSI) and instrumented drop-weight impact testing. The test specimens were composed of six layers of non-crimp fabrics where each layer contained +45°, 90°, −45°, and 0° plies. The goals of the testing were to identify damage responses that may differ from traditional thermoset materials and provide damage characterization data to evaluate current damage prediction analyses and aid improvements to current damage models. The damage was characterized using X-ray computed tomography (CT) and ultrasonic testing (UT). Incremental QSI loading was used on a single specimen to investigate damage growth in nine steps at progressively higher loads. Realtime acoustic emission data were used to determine the unloading points. Unlike typical thermoset composites, the force-displacement was smooth and showed no obvious indications of damage. The primary damage consisted of large lines of fiber fracture on the plies near the impact surface and delaminations through the thickness. Nine specimens were impacted at nominal impact energies of 25 ft-lbs, 30 ft-lbs, and 35 ft-lbs. The force histories at each energy followed nearly identical paths. Again, no obvious signs of damage were observed in any of the force histories. The general damage response in the dynamic tests was similar to the QSI-loaded specimens. However, repeat specimens impacted with a given impact energy showed variations in the damage. Some characteristics of the damage response were different than those typically observed in thermoset composites and will need to be evaluated using current analysis methods.

Composite Materials↗
NASA NTRS1976

Method and apparatus for background signal reduction in opto-acoustic absorption measurement

The sensitivity of an opto-acoustic absorption detector is increased to make it possible to measure trace amounts of constituent gases. A second beam radiation path is created through the sample cell identical to a first path except as to length, alternating the beam through the two paths and minimizing the detected pressure difference for the two paths while the beam wavelength is tuned away from the absorption lines of the sample. Then with the beam wavelength tuned to the absorption line of any constituent of interest, the pressure difference is a measure of trace amounts of the constituent. The same improved detector may also be used for measuring the absorption coefficient of known concentrations of absorbing gases.

Rosengren, L. G.↗
NASA NTRS2024

Effects of Oxide Dispersion on Failure Modes in an Additively Manufactured Superalloy

Additive manufacturing opens new paths for introducing oxide particles into superalloys, to potentially provide oxide dispersion strengthening (ODS) at high temperatures. This provides opportunities to study how such dispersions can influence failure modes for a given superalloy, after nearly identical material processing paths. The objective of this study was to compare monotonic failure modes for additively manufactured superalloys with versus without an introduced oxide dispersion. The superalloy for each case was produced by laser powder bed fusion additive manufacturing. Specimens were subsequently given consistent thermal treatment paths and then tested in tensile and creep tests at varied temperatures. Failure modes were then compared. Additively manufactured NiCrAl without ODS had randomly oriented equiaxed grains while this alloy with 0.25 wt% Y 2 O 3 ODS additions had elongated [001] oriented grains in the build direction. Material made without ODS (“No-ODS”) was nearly completely single phase gamma, while ODS additions resulted in gamma, chromium carbide, and Y-Al-Cr oxide phases, with carbide and oxide phases contents estimated at no more than 13 and 1 vol%, respectively. Compared to No-ODS, material made with ODS had higher tensile strengths at room, 760 and 1093 °C. The elongation of ODS material was lower than No-ODS at room temperature, but higher at 760 °C. At 1093 °C ODS material had higher elongation than No-ODS when tested in the build direction, however elongation was lower for ODS material in the transverse direction at 1093 °C. Creep rupture strain, life, and area reduction at 760 and 1093 °C were all much higher for ODS material compared to No-ODS; 760 °C rupture life was nearly 100 times longer for ODS material. The presence of Y in the ODS material significantly improved oxidation resistance.

supperalloys↗
NASA NTRS2003

A Study of the Opposition Phase Curve in Low Albedo Media

The Opposition Effect, the pronounced non-linear intensity increase in the reflectance phase curve with decreasing phase angle,theta , has long been observed in solar system bodies and in laboratory investigations of the angular scattering properties of particulate media. The size and shape of the phase curve, and the change in linear polarization with theta, have been related to the physical properties of planetary regolith scattering materials. Near zero degrees the increase in reflectance with decreasing phase angle has been attributed to two distinct processes. The first is the elimination of shadows cast between the regolith grains as the phase angle decreases. This is called the shadow hiding opposition effect (SHOE). The second is coherent constructive interference between rays of light traveling along identical but opposite paths in multiply scattering media. This is called the coherent backscattering opposition effect (CBOE).

Nelson, R. M.↗
NASA NTRS2011

Vesper - Venus Chemistry and Dynamics Orbiter - A NASA Discovery Mission Proposal: Submillimeter Investigation of Atmospheric Chemistry and Dynamics

Vesper conducts a focused investigation of the chemistry and dynamics of the middle atmosphere of our sister planet- from the base of the global cloud cover to the lower thermosphere. The middle atmosphere controls the stability of the Venus climate system. Vesper determines what processes maintain the atmospheric chemical stability, cause observed variability of chemical composition, control the escape of water, and drive the extreme super-rotation. The Vesper science investigation provides a unique perspective on the Earth environment due to the similarities in the middle atmosphere processes of both Venus and the Earth. Understanding key distinctions and similarities between Venus and Earth will increase our knowledge of how terrestrial planets evolve along different paths from nearly identical initial conditions.

Chin, Gordon↗
NASA NTRS1984

Performance Measures for Aircraft Landings as a Function of Aircraft Dynamics

A theory of performance measurement for operator controlled systems is presented. The theory permits synthesis of a system performance measure which scores performance on successive data samples based on the impact of the sampled performance on the overall summary of performance. The development of measures for aircraft carrier landings for the glide path and angle of attack control channels is documented. While developing the performance measures, the measures used previously were evaluated and were found to lack the necessary discrimination capability. The previously used measure, the RMS of deviations from the glide path, can, for instance, provide identical scores for both satisfactory and unsatisfactory flight paths. Two types of performance measures developed for aircraft landings are described. Also, an argument is given for the need to test performance measures prior to their use. A suggested test of the measures is offered.

Connelly, E. M.↗
NASA NTRS1974

Extension of Case's method to the two-region critical cylinder and its application as an analytic standard

The normal mode expansion technique is applied to the transformed monoenergetic integral transport equation to develop a solution for the rotationally invariant and axially infinite, critical, two-region cylinder with a finite outer reflector boundary. Isotropic scattering and identical neutron mean free paths in the core and reflector regions are assumed. The solution in terms of singular integral equations is obtained by applying a completeness theorem found for the singular eigenfunctions. Numerical results for a variety of core and reflector multiplying properties and reflector thickness are presented and compared with the results of other method. An example of this type of application is given in a study of approximations inherent in the neutronic design analysis of a small, fast-neutron-spectrum reactor concept proposed as a space power source.

Westfall, R. M.↗
NASA NTRS1982

Mobility aid for the blind

A project to develop an effective mobility aid for blind pedestrians which acquires consecutive images of the scenes before a moving pedestrian, which locates and identifies the pedestrian's path and potential obstacles in the path, which presents path and obstacle information to the pedestrian, and which operates in real-time is discussed. The mobility aid has three principal components: an image acquisition system, an image interpretation system, and an information presentation system. The image acquisition system consists of a miniature, solid-state TV camera which transforms the scene before the blind pedestrian into an image which can be received by the image interpretation system. The image interpretation system is implemented on a microprocessor which has been programmed to execute real-time feature extraction and scene analysis algorithms for locating and identifying the pedestrian's path and potential obstacles. Identity and location information is presented to the pedestrian by means of tactile coding and machine-generated speech.

Source record↗
NASA NTRS1991

Surface properties of Galilean satellites from bistatic radar experiments

The icy moons of Jupiter were the first to show unusual radar backscatter behavior in Earth-based experiments. Studies of Europa, Ganymede, and Callisto revealed strong echoes and a reversed sense of circular polarization. No explanations were entirely satisfactory because of the difficult constraints imposed by the existing data. The (scalar) bidirectional coherence model predicts an opposition effect, or enhancement in the backscatter direction, resulting from coherent addition of backscatter from identical (but oppositely directed) ray paths. The mode decoupling model yields a similar, vector result in which the observed polarization properties of the backscattered wave can also be obtained. The possibilities were considered for conducting such experiments using the Galileo spacecraft. Both conventional oblique-forward bistatic experiments (to determine basic electrical and physical properties of the surface material on centimeter-meter scales) and near-backscatter experiments (to sample the enhanced backscatter lobe) were considered.

Simpson, R. A.↗
NASA NTRS2008

Jet Propulsion Laboratory: Annual Report 2007

Many milestones are celebrated in the business of space exploration, but one of them that arrived this year has particular meaning for us. Half a century ago, on January 31, 1958, the Jet Propulsion Laboratory was responsible for creating America's first satellite, Explorer 1, and joined with the Army to launch it into orbit. That makes 2007 the 50th year we have been sending robotic craft from Earth to explore space. No other event before or since has had such a profound effect on JPL's basic identity, setting it on the path to become the world's leader in robotic solar system exploration. It is not lost on historians that Explorer 1, besides being America's first satellite, was also the first spacecraft from any country to deliver scientific results in its case, the discovery of the Van Allen Radiation Belts that surround Earth. Science, of course, has been the prime motivator for all the dozens of missions that we have lofted into space in the half-century since then. JPL has sent spacecraft to every planet in the solar system from Mercury to Neptune, some of them very sophisticated machines. But in one way or another, they all owe their heritage to the 31-pound bullet-shaped probe JPL shot into space in 1958. Although we have ranged far and wide across the solar system, we have a very strong contingent of satellites and instruments dedicated, like Explorer, to the environment of our home planet. JPL missions have been providing much of the data to establish the facts of global warming - most especially, the melting of ice sheets in Greenland and Antarctica. During the past year, JPL and our parent organization, the California Institute of Technology, have created a task force to focus the special capabilities of the Laboratory and campus on ways to better understand the physics of global change. While Earth is a chaotic and dynamic system capable of large natural variations, evidence is mounting that human activities are playing an increasingly important role. A central piece of this effort is a search for novel energy sources to replace fossil fuels, the combustion of which adds carbon dioxide to our atmosphere. All of this is supported by our worldwide Deep Space Network, which provides the communication link between spacecraft and the ground. In addition, missions are infused with technologies developed by researchers working on projects for non-NASA sponsors as well as on pure research.

Jet Propulsion Laboratory (JPL)↗
NASA NTRS1973

A Method of Monitoring Non-Resonant Raman Lidar Returns During Daylight Hours

A method for using non-resonant Raman lidar during daytime hours is presented. A dual (or quadruple) arrangement of electro-optical channels is set up in the lidar receiver. Each channel contains its own optical spectral response as determined by an appropriate set of interference filters. The incoming signal is split and fed into two channels, filtered (simultaneously) and then inserted into the input terminals of an operational amplifier. The difference signal is selected and amplified whereas the common portion of the signal is highly attenuated (Common Mode Re.jection Ratio = 75-80db). For the present hardware, daylight intensities 10(exp 2)-10(exp 3) times Raman signals are received simultaneously. Mean values of intensities of daylight signals which give rise to a constant differences merely shift the value of the measured variable at the ground. These mean value signals have their common part highly attenuated. The differences of the fluctuation portions of the daylight signal represents a noise signal. Identical (space-time) optical paths for each component of the daylight signal produce the same fluctuational spectra in each channel. Hence noise levels, much less than signal levels, are anticipated. First a N2-H2 ) signal pair is differenced. Then an N2-O2 pair is differenced and used for instrumental normalization purposes. Signal levels to be encountered are quite well known as a result of prior field work. Improved optical design of laser system can reduce mean value of daylight intensities by 10(exp 2). Thus the mean daylight intensity can be set equal to the expected signal levels by more advanced optical design. Performance characteristics of photomultiplier pairs are discussed in this connection.

Cooney, John↗