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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 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Database for LDV Signal Processor Performance Analysis

A comparative and quantitative analysis of various laser velocimeter signal processors is difficult because standards for characterizing signal bursts have not been established. This leaves the researcher to select a signal processor based only on manufacturers' claims without the benefit of direct comparison. The present paper proposes the use of a database of digitized signal bursts obtained from a laser velocimeter under various configurations as a method for directly comparing signal processors.

Baker, Glenn D.↗
NASA NTRS2004

High Resolution Spectroscopic Database for the NASA Earth Observing System Program

The purpose of this project has been to develop and enhance the HITRAN molecular spectroscopic database and associated software to support the observational programs of the Earth Observing System (EOS). Emphasis has been on the EOS projects: the Atmospheric Infrared Sounder (AIRS), the High-Resolution Dynamics Limb Sounder (HIRDLS), Measurements of Pollution in the Troposphere (MOPITT), the Tropospheric Emission Spectrometer (TES), and the Stratospheric Aerosol and Gas Experiment (SAGE III). The HITRAN program is also involved in the Ozone Monitoring Experiment (OMI). The data requirements of these programs in terms of spectroscopy are varied with respect to constituents being observed, required remote-sensing parameters, and spectral coverage. A general requisite is for additional spectral parameters and improvements to existing molecular bands sufficient for the simulation of the observations leading to retrieval of the atmospheric state. In addition, cross-section data for heavier molecular species must be expanded and made amenable to modeling in remote sensing. The effort in the project also includes developing software and distribution to make access, manipulation, and use of HITRAN functional to the EOS program.

Rothman, Laurence↗
NASA NTRS2004

An Aerosol Extinction-to-Backscatter Ratio Database Derived from the NASA Micro-Pulse Lidar Network: Applications for Space-based Lidar Observations

Backscatter lidar signals are a function of both backscatter and extinction. Hence, these lidar observations alone cannot separate the two quantities. The aerosol extinction-to-backscatter ratio, S, is the key parameter required to accurately retrieve extinction and optical depth from backscatter lidar observations of aerosol layers. S is commonly defined as 4*pi divided by the product of the single scatter albedo and the phase function at 180-degree scattering angle. Values of S for different aerosol types are not well known, and are even more difficult to determine when aerosols become mixed. Here we present a new lidar-sunphotometer S database derived from Observations of the NASA Micro-Pulse Lidar Network (MPLNET). MPLNET is a growing worldwide network of eye-safe backscatter lidars co-located with sunphotometers in the NASA Aerosol Robotic Network (AERONET). Values of S for different aerosol species and geographic regions will be presented. A framework for constructing an S look-up table will be shown. Look-up tables of S are needed to calculate aerosol extinction and optical depth from space-based lidar observations in the absence of co-located AOD data. Applications for using the new S look-up table to reprocess aerosol products from NASA's Geoscience Laser Altimeter System (GLAS) will be discussed.

Welton, Ellsworth J.↗
NASA NTRS2005

Lapin Data Interchange Among Database, Analysis and Display Programs Using XML-Based Text Files

The purpose of grant NCC3-966 was to investigate and evaluate the interchange of application-specific data among multiple programs each carrying out part of the analysis and design task. This has been carried out previously by creating a custom program to read data produced by one application and then write that data to a file whose format is specific to the second application that needs all or part of that data. In this investigation, data of interest is described using the XML markup language that allows the data to be stored in a text-string. Software to transform output data of a task into an XML-string and software to read an XML string and extract all or a portion of the data needed for another application is used to link two independent applications together as part of an overall design effort. This approach was initially used with a standard analysis program, Lapin, along with standard applications a standard spreadsheet program, a relational database program, and a conventional dialog and display program to demonstrate the successful sharing of data among independent programs. Most of the effort beyond that demonstration has been concentrated on the inclusion of more complex display programs. Specifically, a custom-written windowing program organized around dialogs to control the interactions have been combined with an independent CAD program (Open Cascade) that supports sophisticated display of CAD elements such as lines, spline curves, and surfaces and turbine-blade data produced by an independent blade design program (UD0300).

Source record↗
NASA NTRS2005

DB90: A Fortran Callable Relational Database Routine for Scientific and Engineering Computer Programs

This report describes a database routine called DB90 which is intended for use with scientific and engineering computer programs. The software is written in the Fortran 90/95 programming language standard with file input and output routines written in the C programming language. These routines should be completely portable to any computing platform and operating system that has Fortran 90/95 and C compilers. DB90 allows a program to supply relation names and up to 5 integer key values to uniquely identify each record of each relation. This permits the user to select records or retrieve data in any desired order.

Wrenn, Gregory A.↗
NASA NTRS2004

EUROPA2: Plan Database Services for Planning and Scheduling Applications

NASA missions require solving a wide variety of planning and scheduling problems with temporal constraints; simple resources such as robotic arms, communications antennae and cameras; complex replenishable resources such as memory, power and fuel; and complex constraints on geometry, heat and lighting angles. Planners and schedulers that solve these problems are used in ground tools as well as onboard systems. The diversity of planning problems and applications of planners and schedulers precludes a one-size fits all solution. However, many of the underlying technologies are common across planning domains and applications. We describe CAPR, a formalism for planning that is general enough to cover a wide variety of planning and scheduling domains of interest to NASA. We then describe EUROPA(sub 2), a software framework implementing CAPR. EUROPA(sub 2) provides efficient, customizable Plan Database Services that enable the integration of CAPR into a wide variety of applications. We describe the design of EUROPA(sub 2) from the perspective of both modeling, customization and application integration to different classes of NASA missions.

Bedrax-Weiss, Tania↗
NASA NTRS2004

NASA Aeronautics and Space Database for bibliometric analysis

The authors use the NASA Aeronautics and Space Database to perform bibliometric analysis of citations. This paper explains their research methodology and gives some sample results showing collaboration trends between NASA Centers and other institutions.

bibliometric analysis↗
NASA NTRS1998

Propagation Models Database

A database of various propagation phenomena models which can be used by the telecommunications systems engineers to obtain the desired parameter values for systems design.

communication satellites radio waves wave propagat↗
NASA NTRS1997

Global Geographic Database in Support of EOS MISR Data Processing

This paper will describe the production of the Ancillary Geographic Product (AGP) in support of the Earth Observing System (EOS) Multi-angle Imaging SpectroRadiometer (MISR) instrument data processing. The AGP is essentially a global database of geographic properties, tailored to the needs of the MISR mission.

ancillary geographic product earth observing syste↗
NASA NTRS1993

GaAs Reliability Database

The database consists of two main sections, the data references and the device reliability records. The reference section contains 8 fields: reference number, date of publication, authors, article title, publisher, volume, and page numbers.

GaAs electric performance↗
NASA NTRS2006

JPL Author Database

A viewgraph presentation describing the background, goals, implementation, uses and future development of JPL's author database is shown.

preprint servers↗
NASA NTRS2006

Validation Database Based Thermal Analysis of an Advanced RPS Concept

Advanced RPS concepts can be conceived, designed and assessed using high-end computational analysis tools. These predictions may provide an initial insight into the potential performance of these models, but verification and validation are necessary and required steps to gain confidence in the numerical analysis results. This paper discusses the findings from a numerical validation exercise for a small advanced RPS concept, based on a thermal analysis methodology developed at JPL and on a validation database obtained from experiments performed at Oregon State University. Both the numerical and experimental configurations utilized a single GPHS module enabled design, resembling a Mod-RTG concept. The analysis focused on operating and environmental conditions during the storage phase only. This validation exercise helped to refine key thermal analysis and modeling parameters, such as heat transfer coefficients, and conductivity and radiation heat transfer values. Improved understanding of the Mod-RTG concept through validation of the thermal model allows for future improvements to this power system concept.

numerical model↗
NASA NTRS2007

Fan Database and Web-tool for Choosing Quieter Spaceflight Fans

One critical aspect of designing spaceflight hardware is the selection of fans to provide the necessary cooling. And with efforts to minimize cost and the tendancy to be conservative with the amount of cooling provided, it is easy to choose an overpowered fan. One impact of this is that the fan uses more energy than is necessary. But, the more significant impact is that the hardware produces much more acoustic noise than if an optimal fan was chosen. Choosing the right fan for a specific hardware application is no simple task. It requires knowledge of cooling requirements and various fan performance characteristics as well as knowledge of the aerodynamic losses of the hardware in which the fan is to be installed. Knowledge of the acoustic emissions of each fan as a function of operating condition is also required in order to choose a quieter fan for a given design point. The purpose of this paper is to describe a database and design-tool that have been developed to aid spaceflight hardware developers in choosing a fan for their application that is based on aerodynamic performance and reduced acoustic emissions as well. This web-based-tool provides a limited amount of fan-data, provides a method for selecting a fan based on its projected operating point, and also provides a method for comparing and contrasting aerodynamic performance and acoustic data from different fans. Drill-down techniques are used to display details of the spectral noise characteristics of the fan at specific operation conditions. The fan aerodynamic and acoustic data were acquired at Ames Research Center in the Experimental Aero-Physics Branch's Anechoic Chamber. Acoustic data were acquired according to ANSI Standard S12.11-1987, "Method for the Measurement of Noise Emitted by Small Air-Moving Devices." One significant improvement made to this technique included automation that allows for a significant increase in flow-rate resolution. The web-tool was developed at Johnson Space Center and is based on the web-development application, SEQUEL, which includes graphics and drill-down capabilities. This paper will describe the type and amount of data taken for the fans and will give examples of this data. This paper will also describe the data-tool and gives examples of how it can be used to choose quieter fans for use in spaceflight hardware.

Allen, Christopher S.↗
NASA NTRS2006

The Future of Asset Management for Human Space Exploration: Supply Classification and an Integrated Database

One of the major logistical challenges in human space exploration is asset management. This paper presents observations on the practice of asset management in support of human space flight to date and discusses a functional-based supply classification and a framework for an integrated database that could be used to improve asset management and logistics for human missions to the Moon, Mars and beyond.

interplanetary supply chain management↗
NASA NTRS1998

Method and system for data clustering for very large databases

Multi-dimensional data contained in very large databases is efficiently and accurately clustered to determine patterns therein and extract useful information from such patterns. Conventional computer processors may be used which have limited memory capacity and conventional operating speed, allowing massive data sets to be processed in a reasonable time and with reasonable computer resources. The clustering process is organized using a clustering feature tree structure wherein each clustering feature comprises the number of data points in the cluster, the linear sum of the data points in the cluster, and the square sum of the data points in the cluster. A dense region of data points is treated collectively as a single cluster, and points in sparsely occupied regions can be treated as outliers and removed from the clustering feature tree. The clustering can be carried out continuously with new data points being received and processed, and with the clustering feature tree being restructured as necessary to accommodate the information from the newly received data points.

Zhang, Tian↗
NASA NTRS2008

Initial Results from the Variable Intensity Sonic Boom Propagation Database

An extensive sonic boom propagation database with low- to normal-intensity booms (overpressures of 0.08 lbf/sq ft to 2.20 lbf/sq ft) was collected for propagation code validation, and initial results and flight research techniques are presented. Several arrays of microphones were used, including a 10 m tall tower to measure shock wave directionality and the effect of height above ground on acoustic level. A sailplane was employed to measure sonic booms above and within the atmospheric turbulent boundary layer, and the sailplane was positioned to intercept the shock waves between the supersonic airplane and the ground sensors. Sailplane and ground-level sonic boom recordings were used to generate atmospheric turbulence filter functions showing excellent agreement with ground measurements. The sonic boom prediction software PCBoom4 was employed as a preflight planning tool using preflight weather data. The measured data of shock wave directionality, arrival time, and overpressure gave excellent agreement with the PCBoom4-calculated results using the measured aircraft and atmospheric data as inputs. C-weighted acoustic levels generally decreased with increasing height above the ground. A-weighted and perceived levels usually were at a minimum for a height where the elevated microphone pressure rise time history was the straightest, which is a result of incident and ground-reflected shock waves interacting.

Haering, Edward A., Jr.↗