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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Systems aspects of COBE science data compression

A general approach to compression of diverse data from large scientific projects has been developed and this paper addresses the appropriate system and scientific constraints together with the algorithm development and test strategy. This framework has been implemented for the COsmic Background Explorer spacecraft (COBE) by retrofitting the existing VAS-based data management system with high-performance compression software permitting random access to the data. Algorithms which incorporate scientific knowledge and consume relatively few system resources are preferred over ad hoc methods. COBE exceeded its planned storage by a large and growing factor and the retrieval of data significantly affects the processing, delaying the availability of data for scientific usage and software test. Embedded compression software is planned to make the project tractable by reducing the data storage volume to an acceptable level during normal processing.

Freedman, I.↗
NASA NTRS2003

A Distributed Data Architecture for 2001 Mars Odyssey Data Distribution

Newer instruments and communications techniques have given scientists unprecedented amounts of data, more than can be feasibly distributed through traditional methods such as mailed CD-ROM's. Leveraging the web makes sense since it enables scientists to request specific data and retrieve products as soon as they're available. Yet defining the middleware system to support such an application has remained just out of reach, until Odyssey. For the first time ever, data from all Odyssey mission instruments were made available through a single system immediately upon delivery to the Planetary Data System (PDS). The Object Oriented Data Technology (OODT) software made such an application possible.

distributed↗
NASA NTRS1985

User's operating procedures. Volume 3: Projects directorate information programs

A review of the user's operating procedures for the scout project automatic data system, called SPADS is presented. SPADS is the results of the past seven years of software development on a prime mini-computer. SPADS was developed as a single entry, multiple cross-reference data management and information retrieval system for the automation of Project office tasks, including engineering, financial, managerial, and clerical support. This volume, three of three, provides the instructions to operate the projects directorate information programs in data retrieval and file maintenance via the user friendly menu drivers.

Haris, C. G.↗
NASA NTRS1994

A Cost and Performance System (CAPS) in a Federal agency

Cost and Performance System (CAPS) is an automated system used from the planning phase through implementation to analysis and documentation. Data is retrievable or available for analysis of cost versus performance anomalies. CAPS provides a uniform system across intra- and international elements. A common system is recommended throughout an entire cost or profit center. Data can be easily accumulated and aggregated into higher levels of tracking and reporting of cost and performance.The level and quality of performance or productivity is indicated in the CAPS model and its process. The CAPS model provides the necessary decision information and insight to the principal investigator/project engineer for a successful project management experience. CAPS provides all levels of management with the appropriate detailed level of data.

Huseonia, W. F.↗
NASA NTRS2022

Apollo Crew Loads Data Mining

INTRODUCTION Human exposure data to dynamic loads in spaceflight are sparse not only because very few crewmembers have flown in space, but also because much of the historic data is no longer readily available. Earth and Moon landings of the Apollo missions are unique and valuable for understanding human tolerance in water landing conditions for both short-duration and long-duration crewmembers as well as informing crew tolerance in standing postures during planetary landings. The goal of this task was to find relevant Apollo data to better understand human tolerance in these scenarios, in order to apply this knowledge to future missions. METHODS The goal of this task was to recover time history data from dynamic phases of flight from crewed Apollo missions. The first phase of the task was to search available records at JSC and other centers to locate the appropriate records at the National Archives in Fort Worth, TX. Once the possible data locations were located, it was planned that one researcher would travel to the National Archives in Fort Worth, TX to collect the relevant Apollo data. Once the data was retrieved, they would be digitized for future use and evaluation, and archived within the Human Physiology, Performance, Protection, and Operations (H-3PO) laboratory within the Human Health and Performance Directorate. These data would be used to assess the feasibility and acceptability of current standards and vehicle design requirements for lunar and Mars missions. Additionally, any medical monitoring required, or physiological changes noted in crewmembers based on dynamic loads would be documented for future use. RESULTS Relevant records were found at Ft. Worth, TX and College Park, MD using the National Archives Online Catalog. In addition to the online catalog, an Archives staff member was able to share an additional inventory list of NASA JSC records held in Ft. Worth, TX. Due to COVID-19, NASA has only recently allowed non-mission essential travel. In addition, the National Archives has also been closed to the public since March 2020. Because of this, travel to the National Archives to search records there has not been possible. CONCLUSION The findings include collections at the National Archives at both Ft. Worth, TX and College Park, MD that could possibly hold the data we are looking for. Unfortunately, the descriptions of each collection are very broad. Though we are hopeful that relevant data is stored in one of these collections, we cannot be sure that we will find what we are looking for. At this time, it is not clear when the Archives will reopen to the public or when NASA will allow travel. Travel to the Archives has been postponed, and will be reassessed at a future date.

T Reiber↗
NASA NTRS1990

Atlas of albedo and absorbed solar radiation derived from Nimbus 7 Earth radiation budget data set, November 1978 to October 1985

An atlas of monthly mean global contour maps of albedo and absorbed solar radiation is presented. This atlas contains 7 years of continuous data from November 1978 through October 1985. The data were retrieved from measurements made by the second Earth Radiation Budget (ERB) wide field-of-view instrument, which flew on the Nimbus 7 spacecraft in 1978. The deconvolution method used to produce these data is briefly discussed here so that the user may understand their generation and limitations. These geographical distributions of albedo and absorbed solar radiation are provided as a resource for researchers studying the radiation budget of the Earth. This atlas of albedo and absorbed solar radiation complements the atlases of outgoing longwave radiation by Bess and Smith, also based on the Nimbus 6 and 7 ERB data.

Smith, G. Louis↗
NASA NTRS1993

Dynamic pattern matcher using incomplete data

This invention relates generally to pattern matching systems, and more particularly to a method for dynamically adapting the system to enhance the effectiveness of a pattern match. Apparatus and methods for calculating the similarity between patterns are known. There is considerable interest, however, in the storage and retrieval of data, particularly, when the search is called or initiated by incomplete information. For many search algorithms, a query initiating a data search requires exact information, and the data file is searched for an exact match. Inability to find an exact match thus results in a failure of the system or method.

Johnson, Gordon G.↗
NASA NTRS1985

User's operating procedures. Volume 2: Scout project financial analysis program

A review is presented of the user's operating procedures for the Scout Project Automatic Data system, called SPADS. SPADS is the result of the past seven years of software development on a Prime mini-computer located at the Scout Project Office, NASA Langley Research Center, Hampton, Virginia. SPADS was developed as a single entry, multiple cross-reference data management and information retrieval system for the automation of Project office tasks, including engineering, financial, managerial, and clerical support. This volume, two (2) of three (3), provides the instructions to operate the Scout Project Financial Analysis program in data retrieval and file maintenance via the user friendly menu drivers.

Harris, C. G.↗
NASA NTRS2003

Data Access Tools And Services At The Goddard Distributed Active Archive Center (GDAAC)

As one of the largest providers of Earth Science data from the Earth Observing System, GDAAC provides the latest data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Atmospheric Infrared Sounder (AIRS), Solar Radiation and Climate Experiment (SORCE) data products via GDAAC's data pool (50TB of disk cache). In order to make this huge volume of data more accessible to the public and science communities, the GDAAC offers multiple data access tools and services: Open Source Project for Network Data Access Protocol (OPeNDAP), Grid Analysis and Display System (GrADS/DODS) (GDS), Live Access Server (LAS), OpenGlS Web Map Server (WMS) and Near Archive Data Mining (NADM). The objective is to assist users in retrieving electronically a smaller, usable portion of data for further analysis. The OPeNDAP server, formerly known as the Distributed Oceanographic Data System (DODS), allows the user to retrieve data without worrying about the data format. OPeNDAP is capable of server-side subsetting of HDF, HDF-EOS, netCDF, JGOFS, ASCII, DSP, FITS and binary data formats. The GrADS/DODS server is capable of serving the same data formats as OPeNDAP. GDS has an additional feature of server-side analysis. Users can analyze the data on the server there by decreasing the computational load on their client's system. The LAS is a flexible server that allows user to graphically visualize data on the fly, to request different file formats and to compare variables from distributed locations. Users of LAS have options to use other available graphics viewers such as IDL, Matlab or GrADS. WMS is based on the OPeNDAP for serving geospatial information. WMS supports OpenGlS protocol to provide data in GIs-friendly formats for analysis and visualization. NADM is another access to the GDAAC's data pool. NADM gives users the capability to use a browser to upload their C, FORTRAN or IDL algorithms, test the algorithms, and mine data in the data pool. With NADM, the GDAAC provides an environment physically close to the data source. NADM will benefit users with mining or offer data reduction algorithms by reducing large volumes of data before transmission over the network to the user.

Pham, Long↗
NASA NTRS2005

Reducing costs of managing and accessing navigation and ancillary data by relying on the extensive capabilities of NASA's spice system

The SPICE system of navigation and ancillary data possesses a number of traits that make its use in modern space missions of all types highly cost efficient. The core of the system is a software library providing API interfaces for storing and retrieving such data as trajectories, orientations, time conversions, and instrument geometry parameters. Applications used at any stage of a mission life cycle can call SPICE APIs to access this data and compute geometric quantities required for observation planning, engineering assessment and science data analysis. SPICE is implemented in three different languages, supported on 20+ computer environments, and distributed with complete source code and documentation. It includes capabilities that are extensively tested by everyday use in many active projects and are applicable to all types of space missions - flyby, orbiters, observatories, landers and rovers. While a customer's initial SPICE adaptation for the first mission or experiment requires a modest effort, this initial effort pays off because adaptation for subsequent missions/experiments is just a small fraction of the initial investment, with the majority of tools based on SPICE requiring no or very minor changes.

ancillary data↗
NASA NTRS2000

1DVAR Analysis of Temperature and Humidity Using GPS Radio Occultation Data

The Global Positioning System enables positioning in 3 dimensions about our planet. It has been operational since 1994. Twenty-four satellites are used to aclile\,e this performance. The signals sent by these satellites are electromagnetic waves travelling through our atmosphere down to the small receivers used by the civilian community and the military. Because of varying meteorological conditions (namely, temperature and humidity changes along the ray path), the rays do not travel in a straight line. They bend towards the surface. As a consequence, the ray path between two points is longer than a straight line, and the time it takes for a signal to travel this distance is longer. In 1995, a small GPS receiver was launched on a satellite (GPS/MET). It become possible to perform radio occultations around the Earth: the source - one of the 24 GPS satellites - is seen by the receiver as it rises or sets around the other side of the Earth. When the source disappears, the receiver progressively loses the signals. By measuring accurately the time delay between the emission and the reception of the signal, it is possible to infer which part of the delay is due to the atmosphere. We use GPS/MET data to retrieve temperature and humidity profiles simultaneously. A specific method is implemented: it combines information from numerical forecasts and GPS observations in an optimal way. Comparing the result with an independent source of observations (weather balloons), we demonstrate that GPS data have the potential to improve weather analyses. We also show that improved temperature and humidity profiles can be obtained using information from a forecast model. This confirms results obtained in this study using simulated data.

Poli, Paul↗
NASA NTRS2018

Air Traffic Management-eXploration Testbed for Urban Air Mobility Research and Development

The presentation will describe the architecture, current capabilities and some future enhancements of the testbed that is being developed at the National Aeronautics and Space Administration (NASA) to enable benefit, impact, safety and cost assessments for accelerating the deployment of air traffic management concept and technologies in the national airspace system. The testbed will support analysis of operational feasibility of urban air mobility operations, a part of NASA's Air Traffic Management eXploration project, and provide the data needed by regulatory agencies charged with public safety. Introduction of concepts and technologies, especially new concepts and technologies, is difficult and often takes decades because of the inability to assess the operational impact of the interaction between the proposed concept and technology and operationally deployed systems in terms of system-wide safety, traffic flow efficiency, roles and workload of controllers and traffic managers, and impact on airlines and other operators. To overcome these limitations, the testbed is developing infrastructure to enable mathematical modeling, human-in-the-loop evaluations and testing with operational systems in a simulated environment. In addition to the difficulty of establishing communications between geographically distributed systems, downloading/installing software, and management of startup, error-handling and shutdown, a major impediment for conducting simulations and human-in-the-loop testing with operational systems is the tedious manual scenario generation process. Several of these difficulties have been addressed in the current state of the testbed. The testbed can be described in terms of the following elements (1) web-based frontend and backend, (2) Testbed Builder, (3) Data Distribution Service, (4) Component Library, (5) Simulation Management, and (6) Scenario Generation. The web-based frontend and backend enable the user to interact with the testbed for tasks such as composing a simulation, running a simulation and retrieving output data. The Testbed Builder application launched from the web frontend is a graphical user interface for the user to drag-and-drop and connect predefined blocks for composing a simulation/scenario generation task. The Builder writes a set of instructions for Simulation Management based on the links between the blocks and the block properties such as the component (executable) associated with a particular block. Management of the distributed simulation is accomplished by Execution and Component Managers. Execution Manager interprets the instructions provided by the Builder to instruct the Component Managers to download components from the Component Library to specified computers and to start them up. Once started, the components communicate with each other by publishing messages and subscribing to messages that are delivered by the Data Distribution Service. The Scenario Generation capability can be used for creating traffic scenarios for Multi-Aircraft Control System, which has been used extensively at NASA for human-in-the-loop-based concept evaluations. The presentation will provide a testbed enabled example scenario of Multi-Aircraft Control System based simulation in which the urban air mobility pilot using the conflict detection and resolution system would interact with the air traffic controllers for resolving conflicts with other aircraft during terminal area operations.

Testbed↗
NASA NTRS2018

Air Traffic Management-eXploration Testbed for Urban Air Mobility Research and Development

The presentation will describe the architecture, current capabilities and some future enhancements of the testbed that is being developed at the National Aeronautics and Space Administration (NASA) to enable benefit, impact, safety and cost assessments for accelerating the deployment of air traffic management concept and technologies in the national airspace system. The testbed will support analysis of operational feasibility of urban air mobility operations, a part of NASA's Air Traffic Management eXploration project, and provide the data needed by regulatory agencies charged with public safety. Introduction of concepts and technologies, especially new concepts and technologies, is difficult and often takes decades because of the inability to assess the operational impact of the interaction between the proposed concept and technology and operationally deployed systems in terms of system-wide safety, traffic flow efficiency, roles and workload of controllers and traffic managers, and impact on airlines and other operators. To overcome these limitations, the testbed is developing infrastructure to enable mathematical modeling, human-in-the-loop evaluations and testing with operational systems in a simulated environment. In addition to the difficulty of establishing communications between geographically distributed systems, downloading/installing software, and management of startup, error-handling and shutdown, a major impediment for conducting simulations and human-in-the-loop testing with operational systems is the tedious manual scenario generation process. Several of these difficulties have been addressed in the current state of the testbed. The testbed can be described in terms of the following elements- (1) web-based frontend and backend, (2) Testbed Builder, (3) Data Distribution Service, (4) Component Library, (5) Simulation Management, and (6) Scenario Generation. The web-based frontend and backend enable the user to interact with the testbed for tasks such as composing a simulation, running a simulation and retrieving output data. The Testbed Builder application launched from the web frontend is a graphical user interface for the user to drag-and-drop and connect predefined blocks for composing a simulation/scenario generation task. The Builder writes a set of instructions for Simulation Management based on the links between the blocks and the block properties such as the component (executable) associated with a particular block. Management of the distributed simulation is accomplished by Execution and Component Managers. Execution Manager interprets the instructions provided by the Builder to instruct the Component Managers to download components from the Component Library to specified computers and to start them up. Once started, the components communicate with each other by publishing messages and subscribing to messages that are delivered by the Data Distribution Service. The Scenario Generation capability can be used for creating traffic scenarios for Multi-Aircraft Control System, which has been used extensively at NASA for human-in-the-loop-based concept evaluations. The presentation will provide a testbed enabled example scenario of Multi-Aircraft Control System based simulation in which the urban air mobility pilot using the conflict detection and resolution system would interact with the air traffic controllers for resolving conflicts with other aircraft during terminal area operations.

Simulation↗
NASA NTRS1992

Intelligent text retrieval in the NASA astrophysics data system

In collaboration with the NASA Scientific and Technical Information System, the NASA Astrophysics Data System (ADS) is establishing a service to provide access to the literature abstracts relevant to astronomy in the NASA Scientific and Technical Aerospace Reports and the International Aerospace Abstracts (together also known as NASA RECON). The service will include several sophisticated retrieval methods, which may be combined. Included will be methods to perform relevancy ranking from natural language queries, synonym and misspelling recognition, author name translation (e.g. for multiple transliteration possibilities), and other features. The capabilities of the current release will be shown, and the plans for the near future will be discussed.

Kurtz, M. J.↗
NASA NTRS1990

An analysis of cloud property retrieval using HIRS-2 and AVHRR radiometric data

The principal advantage of the HIRS cloud height retrieval is to provide an unbiased estimate of cloud height for optically thin, high cloud. This capability is employed to examine the relationship of cirrus visible reflectance to thermal IR emittance. By combining data from the HIRS-2 and AVHRR instruments on the NOAA operational satellites the proposed method attempts to improve the ability of existing satellite radiometers to recover information on middle-level and high-level clouds. This combination of data sets leads to an improved cloud recovery algorithm for the detection and analysis of cirrus clouds.

Baum, Bryan A.↗
NASA NTRS2017

Radiometric and spectral stray light correction for the Portable Remote Imaging Spectrometer (PRISM) coastal ocean sensor

The airborne Portable Remote Imaging Spectrometer (PRISM) instrument is based on a fast (F/1.8) Dyson spectrometer operating at 350-1050 nm and a two-mirror telescope combined with a Teledyne HyViSI 6604A detector array. Raw PRISM data contain electronic and optical artifacts that must be removed prior to radiometric calibration. We provide an overview of the process transforming raw digital numbers to calibrated radiance values. Electronic panel artifacts are first corrected using empirical relationships developed from laboratory data. The instrument spectral response functions (SRF) are reconstructed using a measurement-based optimization technique. Removal of SRF effects from the data improves retrieval of true spectra, particularly in the typically low-signal near-ultraviolet and near-infrared regions. As a final step, radiometric calibration is performed using corrected measurements of an object of known radiance. Implementation of the complete calibration procedure maximizes data quality in preparation for subsequent processing steps, such as atmospheric removal and spectral signature classification.

Thompson, David R.↗
NASA NTRS1989

Column atmospheric water vapor retrievals from airborne imaging spectrometer data

High-spatial-resolution column atmospheric water vapor amounts were derived from spectral data collected by the Airborne Visible Infrared Imaging Spectrometer (AVIRIS). The quantitative derivation is made by curve fitting observed spectra with calculated spectra in the 1.14- and 0.94-micron water-vapor band absorption regions with a nonlinear least-squares technique. The precision of the retrieved column water vapor is approximately 5 percent. The derived column water vapor amounts are independent of the absolute surface reflectance. Curve fitting of spectra near 1 micron from areas covered with vegetation indicates that both the amount of atmospheric water vapor and the moisture content of vegetation can be retrieved simultaneously. It should be possible to measure column water vapor over land areas from satellite altitude with the proposed high-resolution imaging spectrometer or even the moderate-resolution imaging spectrometer.

Gao, Bo-Cai↗