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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 NTRS2018

The Evolution of Gridded NUCAPS: An Overview of Research to Operations Activities

The next-generation S-NPP and NOAA-20 Cross-track Infrared Sounder (CrIS) temperature and moisture profiles can provide valuable observations; (1) Where conventional radiosonde observations are sparse, (2) Between radiosonde launches. CrIS observations are combined with the Advanced Technology Microwave Sounder (ATMS) to produce high quality vertical soundings in clear and partly cloudy conditions. NUCAPS (NOAA Unique Combined Atmospheric Processing System) is the operational algorithm for processing combined hyperspectral infrared and microwave measurements. NUCAPS Soundings are operationally available in AWIPS as Skew-T plots. The capability to visualize the data in plan view or cross section would be valuable to maximize the benefits of NUCAPS data in AWIPS. A multi-organizational collaboration through the JPPS Soundings Applications Initiative developed the capability for plan view and cross section displays of NUCAPS in AWIPS (i.e., Gridded NUCAPS).

Berndt, Emily↗

NASA NTRS1993

Status of VGRID/USM3D aero analysis system

The topics are presented in viewgraph form and include the following: grid generation; flow solver; graphic postprocessing; dissemination; customer applications; and plans.

Neal T Frink↗

NASA NTRS2010

Decomposition Algorithm for Global Reachability on a Time-Varying Graph

A decomposition algorithm has been developed for global reachability analysis on a space-time grid. By exploiting the upper block-triangular structure, the planning problem is decomposed into smaller subproblems, which is much more scalable than the original approach. Recent studies have proposed the use of a hot-air (Montgolfier) balloon for possible exploration of Titan and Venus because these bodies have thick haze or cloud layers that limit the science return from an orbiter, and the atmospheres would provide enough buoyancy for balloons. One of the important questions that needs to be addressed is what surface locations the balloon can reach from an initial location, and how long it would take. This is referred to as the global reachability problem, where the paths from starting locations to all possible target locations must be computed. The balloon could be driven with its own actuation, but its actuation capability is fairly limited. It would be more efficient to take advantage of the wind field and ride the wind that is much stronger than what the actuator could produce. It is possible to pose the path planning problem as a graph search problem on a directed graph by discretizing the spacetime world and the vehicle actuation. The decomposition algorithm provides reachability analysis of a time-varying graph. Because the balloon only moves in the positive direction in time, the adjacency matrix of the graph can be represented with an upper block-triangular matrix, and this upper block-triangular structure can be exploited to decompose a large graph search problem. The new approach consumes a much smaller amount of memory, which also helps speed up the overall computation when the computing resource has a limited physical memory compared to the problem size.

Kuwata, Yoshiaki↗

NASA NTRS1988

Imaging solar flares in hard X-rays and gamma raysfrom balloon-borne platforms

Hard X-rays and gamma rays carry the most direct evidence available for the roles of accelerated particles in solar flares. An approach that employs a spatial Fourier-transform technique for imaging the sources of these emissions is described and plans for developing a balloon-borne gamma ray imaging device (GRID) based on this instrumental approach is presented. This instrument, GRID on a balloon, would enable observations with a 1.6 arcsecond angular resolution, 10 millisecond time resolution, and whole-Sun field of view on long-duration balloon flights during MAX 1991.

Crannell, Carol JO↗

NASA NTRS1989

Hypersonic CFD applications at NASA Langley using CFL3D and CFL3DE

The CFL3D/CFL3DE CFD codes and the industrial use status of the codes are outlined. Comparison of grid density, pressure, heat transfer, and aerodynamic coefficience are presented. Future plans related to the National Aerospace Plane Program are briefly outlined.

Richardson, Pamela F.↗

NASA NTRS2010

TPSAS-NF1676L-10980-DND

We plan to perform the following sets of computations on unadapted (fixed) grids: 1) Structured RANS set 1 (Code: CFL3D, Grid: Str-OnetoOne-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Spalart-Allmaras), 2) Structured RANS set 2 (Code: CFL3D, Grid: Str-OnetoOne-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Menter SST), 3) Structured RANS set 3 (time permitting) (Code: CFL3D, Grid: Str-OnetoOne-B-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Menter SST), 4) Unstructured RANS set 1 (Code: FUN3D, Grid: Unst-Mixed-FromTet-Nodecentered-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Spalart-Allmaras), and 5) Unstructured RANS set 2 (time permitting) (Code: FUN3D, Grid: Unst-Hex-FromOnetoOne-A-v1 (supplied by HiLiftPW-1 committee), Turbulence model: Spalart-Allmaras),. Optional case 3 is not being computed. CFL3D is a structured upwind-biased cell-centered RANS code,1 and FUN3D is an unstructured upwind-biased node-centered RANS code

Elizabeth M Lee-Rausch↗

NASA NTRS2010

TPSAS-NF1676L-10454-DND

C L Rumsey↗

NASA NTRS1994

Grid resolution and solution convergence for Mars Pathfinder forebody

As part of the Discovery Program, NASA Plans to launch a series of probes to Mars. The Mars Pathfinder project is the first of this series with a scheduled Mars arrival in July 1997. The entry vehicle will perform a direct entry into the atmosphere and deliver a lander to the surface. Predicting the entry vehicle's flight performance and designing the forebody heatshield requires knowledge of the expected aerothermodynamic environment. Much of this knowledge can be obtained through computational fluid dynamic (CFD) analysis.

Nettelhorst, Heather L.↗

NASA NTRSDate not supplied

Establishing a Lunar Surface Power Grid

The National Aeronautics and Space Administration (NASA) is seeking to develop a lunar surface power system for its Artemis missions as well as for planned future commercial lunar surface activities. This power system is composed of a number of assets which contain electrical loads and many of these contain energy resources. These assets can be connected to form a grid, which allows power to be shared between the system’s distributed energy resources. This grid can provide backup power to existing assets as well as primary power to future assets. A trade study was conducted for an Artemis scale grid, which has identified 3 kV AC as an ideal transmission voltage. Development work has also begun for a universal modular interface converter (UMIC) which connects assets and microgrids operating at 120 V DC space power to the grid. Products from this grid definition and UMIC development work will enable highly reliable and available power for Artemis and future planetary surface missions, which is key to achieving NASA’s long term vision of space exploration.

Planetary surface power↗

NASA NTRS2003

Space-based Operations Grid Prototype

The Space based Operations Grid is intended to integrate the "high end" network services and compute resources that a remote payload investigator needs. This includes integrating and enhancing existing services such as access to telemetry, payload commanding, payload planning and internet voice distribution as well as the addition of services such as video conferencing, collaborative design, modeling or visualization, text messaging, application sharing, and access to existing compute or data grids. Grid technology addresses some of the greatest challenges and opportunities presented by the current trends in technology, i.e. how to take advantage of ever increasing bandwidth, how to manage virtual organizations and how to deal with the increasing threats to information technology security. We will discuss the pros and cons of using grid technology in space-based operations and share current plans for the prototype. It is hoped that early on the prototype can incorporate many of the existing as well as future services that are discussed in the first paragraph above to cooperating International Space Station Principle Investigators both nationally and internationally.

Bradford, Robert N.↗

NASA NTRS2021

Small UAV Flight Planning in Urban Environments

This work proposes a fast algorithm for generating obstacle-free and wind-efficient flight paths at a constant above-ground-level altitude in urban environments because a fast flight path planning algorithm is an essential function or service needed for enabling small unmanned aerial vehicle (sUAV) to operate in urban environments within Class G airspace. The proposed method first converts the 3D path planning problem to a 2D problem by constructing an obstacle map at a given above-ground-level altitude. A quad-tree decomposition is then used to build a search space in terms of obstacle occupancy and wind difference. The wind cost of traveling through each cell is defined based on energy consumption under various wind conditions. A repulsive potential is also adopted to make sure that the flight plans stay away from obstacles. The Theta* search algorithm, a variant of A* algorithm, is applied to mitigate the path angle change constraints introduced by grid-based graphs. With the Theta* and postsmoothing techniques, an obstacle-free, wind efficient, and constant above-ground-level flight plan can be quickly generated for sUAV operations in urban environments while meeting the lateral path angle constraints. The results showed that the path planning algorithm is efficient and can be finished within several seconds. With a proper choice of wind coefficient, the proposed path planning algorithm outperforms the multiple-shooting trajectory optimization method even in an obstacle-free environment. With the flexibility of incorporating other geo-related costs and computation efficiency, the proposed algorithm shows the potential for real-time flight path planning in complex urban environments.

Path planning↗

NASA NTRS1997

Bidirectional Reflectance Functions for Application to Earth Radiation Budget Studies

Reflected solar radiative fluxes emerging for the Earth's top of the atmosphere are inferred from satellite broadband radiance measurements by applying bidirectional reflectance functions (BDRFs) to account for the anisotropy of the radiation field. BDRF's are dependent upon the viewing geometry (i.e. solar zenith angle, view zenith angle, and relative azimuth angle), the amount and type of cloud cover, the condition of the intervening atmosphere, and the reflectance characteristics of the underlying surface. A set of operational Earth Radiation Budget Experiment (ERBE) BDRFs is available which was developed from the Nimbus 7 ERB (Earth Radiation Budget) scanner data for a three-angle grid system, An improved set of bidirectional reflectance is required for mission planning and data analysis of future earth radiation budget instruments, such as the Clouds and Earth's Radiant Energy System (CERES), and for the enhancement of existing radiation budget data products. This study presents an analytic expression for BDRFs formulated by applying a fit to the ERBE operational model tabulations. A set of model coefficients applicable to any viewing condition is computed for an overcast and a clear sky scene over four geographical surface types: ocean, land, snow, and desert, and partly cloudy scenes over ocean and land. The models are smooth in terms of the directional angles and adhere to the principle of reciprocity, i.e., they are invariant with respect to the interchange of the incoming and outgoing directional angles. The analytic BDRFs and the radiance standard deviations are compared with the operational ERBE models and validated with ERBE data. The clear ocean model is validated with Dlhopolsky's clear ocean model. Dlhopolsky developed a BDRF of higher angular resolution for clear sky ocean from ERBE radiances. Additionally, the effectiveness of the models accounting for anisotropy for various viewing directions is tested with the ERBE along tract data. An area viewed from nadir and from the side give two different radiance measurements but should yield the same flux when converted by the BDRF. The analytic BDRFs are in very good qualitative agreement with the ERBE models. The overcast scenes exhibit constant retrieved albedo over viewing zenith angles for solar zenith angles less than 60 degrees. The clear ocean model does not produce constant retrieved albedo over viewing zenith angles but gives an improvement over the ERBE operational clear sky ocean BDRF.

Manalo-Smith, N.↗

NASA NTRS2004

Challenges of Moving IPG into Production

Over the past 5-6 years, NASA has been developing the Information Power Grid and has a persistent testbed currently based on GT2.4.2. This presentation will begin with an overview of IPG status and services, discuss key milestones in IPG development, and present early as well as expected applications. The presentation will discuss some of the issues encountered in developing a grid including the tension between providing centralized and distributed computing. These issues also affect how the grid is moved into full production. Finally, the presentation will provide current plans for moving IPG into full production, including gaining broad user input, developing acceptance criteria from the production operations group, planning upgrades, and training users.

Schulbach, Cathy↗

NASA NTRS2019

Application of NUCAPS for Thermodynamic Fire Weather Analysis

NUCAPS is the NOAA Operational Retrieval algorithm for SNPP and NOAA-20 CrIS/ATMS temperature, moisture, and trace gas retrievals. The JPSS Sounding Initiative developed an experimental capability for plan-view and cross section displays of NUCAPS Soundings in AWIPS (i.e., Gridded NUCAPS). As a result of successful assessment with the NWS Anchorage CWSU and the Hazardous Weather Testbed, Gridded NUCAPS will be baselined in AWIPS 19.2.1. This offers a new opportunity to explore use of Gridded NUCAPS for various forecasting topics, especially in data sparse, remote areas. Case studies were examined to assess the utility of NUCAPS Soundings and the NUCAPS Soundings and Gridded product for fire weather potential.

Allen, Roger↗

NASA NTRS2016

IN31A-1734 Development and Evaluation of a Gridded CrIS/ATMS Visualization for Operational Forecasting

A collaborative effort between SPoRT, CIMSS, CIRA, GINA, and NOAA has produced a unique gridded visualization of real-time CrIS/ATMS sounding products. This product uses the NUCAPS retrieval algorithm and polar2grid software to generate plan-view and cross-section visualization for forecast challenges associated with cold air aloft and convective potential. Forecasters at select partner offices have been able to view the Gridded NUCAPS products in AWIPS alongside other operational data products with generally favorable feedback.

aviation↗

NASA NTRS2009

Primordial Inflation Polarization Explorer: Status and Plans

The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

Kogut, Alan↗

NASA NTRS2000

Reflective Focused Schlieren System Improved for Use in 10- by 10-Foot Supersonic Wind Tunnel

The reflective focused schlieren system that was developed for use in the 10- by 10-Foot Supersonic Wind Tunnel (10x10 SWT) at the NASA Glenn Research Center at Lewis Field as part of the Unstart Test Program was improved this past year. In April 1999, the development and use of the system was presented at the Supersonic Tunnel Association International in Bedford, England. A focused schlieren system is similar to a standard schlieren system in that shock waves coming from an object in supersonic flow can be seen using a standard video camera. Unlike the standard schlieren system, which produces a two-dimensional schlieren image, a focused schlieren system can produce a threedimensional image. The preceding drawing shows the components of the reflective focused schlieren system being developed for use in the 10x10 SWT. Although the system worked well for the Unstart Test Program, it was not sensitive enough to be classified as a facility capability. Therefore, a program was implemented to improve the sensitivity of the reflective focused schlieren system so that it could be a facility capability for Glenn's 10x10 SWT. Several techniques were implemented to increase the sensitivity and to improve the overall operation of the system. These included refinement of the source grid, improvement in the cutoff grid production, improvement of the source grid and cutoff grid alignment, installation of an improved light source, and incorporation of an image-enhancing system. These changes are being implemented with the system set up in the laboratory. A checkout test of the system is planned in the 10x10 SWT in March 2000. Of these techniques, the most developed is the refinement of the source grid. The original system had a pattern of -in. by -in. squares on -in. centers (distance between the center points of adjacent squares). This gave a ratio of light to dark (reflective to nonreflective area) of 3:1. The recommended ratio is 1:1. In order to accomplish this, a pattern of -in.-diameter dots on 3/8-in. centers was developed. Preliminary tests with this pattern showed an increase in system sensitivity and image clarity. Further testing and refinement are scheduled. The former and improved dot patterns are shown. The use of glass plates to produce the cutoff grid improved the cutoff grid's quality and helped to align it with the source grid. The cutoff grid, which is the negative of the source grid, is made by exposing photography film (or glass plates) to the proper light while it is installed in the focused schlieren system. The exposed film or plate is removed from the system and then developed as a photograph negative. Because the glass plates are rigid, they eliminate the risk of distortion when the negative is reinstalled in the system and realigned with the source grid.

Williamson, Gary Scott↗

NASA NTRS1990

A description of the Global Resources Information Database

This paper describes the Global Resources Information Database (GRID), which is part of the Global Environmental Monitoring (GEM) Program. The following four objectives were established for GRID: (1) to collect and disseminate geographical information; (2) to construct within developing countries a geographical information system (GIS); (3) to demonstrate the ability of GIS to fuse global and national data sets for resource and environment management and planning at the national level; and (4) to train individuals from developing countries in remote sensing technology. The activities of GRID are coordinated at the GEM center at Nairobi (Kenya).

Vermillion, Charles H.↗