7,048 research outputs found
Proceedings of the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications
The proceedings of the National Space Science Data Center Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications held July 23 through 25, 1991 at the NASA/Goddard Space Flight Center are presented. The program includes a keynote address, invited technical papers, and selected technical presentations to provide a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disk and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's
NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 2
This report contains copies of nearly all of the technical papers and viewgraphs presented at the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Application. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include the following: magnetic disk and tape technologies; optical disk and tape; software storage and file management systems; and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's
The Study of the Pioneer Anomaly: New Data and Objectives for New Investigation
Radiometric tracking data from Pioneer 10 and 11 spacecraft has consistently
indicated the presence of a small, anomalous, Doppler frequency drift,
uniformly changing with a rate of ~6 x 10^{-9} Hz/s; the drift can be
interpreted as a constant sunward acceleration of each particular spacecraft of
a_P = (8.74 \pm 1.33) x 10^{-10} m/s^2. This signal is known as the Pioneer
anomaly; the nature of this anomaly remains unexplained. We discuss the efforts
to retrieve the entire data sets of the Pioneer 10/11 radiometric Doppler data.
We also report on the recently recovered telemetry files that may be used to
reconstruct the engineering history of both spacecraft using original project
documentation and newly developed software tools. We discuss possible ways to
further investigate the discovered effect using these telemetry files in
conjunction with the analysis of the much extended Doppler data. We present the
main objectives of new upcoming study of the Pioneer anomaly, namely i)
analysis of the early data that could yield the direction of the anomaly, ii)
analysis of planetary encounters, that should tell more about the onset of the
anomaly, iii) analysis of the entire dataset, to better determine the anomaly's
temporal behavior, iv) comparative analysis of individual anomalous
accelerations for the two Pioneers, v) the detailed study of on-board
systematics, and vi) development of a thermal-electric-dynamical model using
on-board telemetry. The outlined strategy may allow for a higher accuracy
solution for a_P and, possibly, will lead to an unambiguous determination of
the origin of the Pioneer anomaly.Comment: 43 pages, 40 figures, 3 tables, minor changes before publicatio
NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 1
Papers and viewgraphs from the conference are presented. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disks and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's
Factors shaping the evolution of electronic documentation systems
The main goal is to prepare the space station technical and managerial structure for likely changes in the creation, capture, transfer, and utilization of knowledge. By anticipating advances, the design of Space Station Project (SSP) information systems can be tailored to facilitate a progression of increasingly sophisticated strategies as the space station evolves. Future generations of advanced information systems will use increases in power to deliver environmentally meaningful, contextually targeted, interconnected data (knowledge). The concept of a Knowledge Base Management System is emerging when the problem is focused on how information systems can perform such a conversion of raw data. Such a system would include traditional management functions for large space databases. Added artificial intelligence features might encompass co-existing knowledge representation schemes; effective control structures for deductive, plausible, and inductive reasoning; means for knowledge acquisition, refinement, and validation; explanation facilities; and dynamic human intervention. The major areas covered include: alternative knowledge representation approaches; advanced user interface capabilities; computer-supported cooperative work; the evolution of information system hardware; standardization, compatibility, and connectivity; and organizational impacts of information intensive environments
Minutes of the CD-ROM Workshop
The workshop described in this document had two goals: (1) to establish guidelines for the CD-ROM as a tool to distribute datasets; and (2) to evaluate current scientific CD-ROM projects as an archive. Workshop attendees were urged to coordinate with European groups to develop CD-ROM, which is already available at low cost in the U.S., as a distribution medium for astronomical datasets. It was noted that NASA has made the CD Publisher at the National Space Science Data Center (NSSDC) available to the scientific community when the Publisher is not needed for NASA work. NSSDC's goal is to provide the Publisher's user with the hardware and software tools needed to design a user's dataset for distribution. This includes producing a master CD and copies. The prerequisite premastering process is described, as well as guidelines for CD-ROM construction. The production of discs was evaluated. CD-ROM projects, guidelines, and problems of the technology were discussed
Results of Skylab experiment T00-2, manual navigation sightings
An analysis of navigation data collected using a hand-held space sextant on the second and third manned Skylab missions was presented. From performance data and astronaut comments it was determined that: (1) the space sextant, the sighting station, and the sighting techniques require modification; (2) the sighting window must be of good optical quality; (3) astronaut performance was stable over long mission time; and (4) sightings made with a hand-held sextant were accurate and precise enough for reliable interplanetary manual navigation
The Third NASA Goddard Conference on Mass Storage Systems and Technologies
This report contains copies of nearly all of the technical papers and viewgraphs presented at the Goddard Conference on Mass Storage Systems and Technologies held in October 1993. The conference served as an informational exchange forum for topics primarily relating to the ingestion and management of massive amounts of data and the attendant problems involved. Discussion topics include the necessary use of computers in the solution of today's infinitely complex problems, the need for greatly increased storage densities in both optical and magnetic recording media, currently popular storage media and magnetic media storage risk factors, data archiving standards including a talk on the current status of the IEEE Storage Systems Reference Model (RM). Additional topics addressed System performance, data storage system concepts, communications technologies, data distribution systems, data compression, and error detection and correction
Signature Files: An Integrated Access Method for Formatted and Unformatted Databases
The signature file approach is one of the most powerful information storage and retrieval techniques which is used for finding the data objects that are relevant to the user queries. The main idea of all signature based schemes is to reflect the essence of the data items into bit pattern (descriptors or signatures) and store them in a separate file which acts as a filter to eliminate the non aualifvine data items for an information reauest. It provides an integrated access method for both formattid and formatted databases. A complative
overview and discussion of the proposed signatnre generation methods and the major signature file organization schemes are presented. Applications of the signature techniques to formatted and unformatted databases, single and multiterm query cases, serial and paratlei architecture. static and dynamic environments are provided with a special emphasis on the multimedia databases where the pioneering prototype systems
using signatnres yield highly encouraging results
Audit implications of electronic document management; Auditing procedure study;
https://egrove.olemiss.edu/aicpa_guides/1034/thumbnail.jp
- …