(Contract F19628-87-K-0003; AF Proj. 7670) (AD-A225132; GL-TR-89-0286; SR-1) Avail: NTIS HC/MF A03 CSCL 04/2 The overall objective of this project is to derive atmospheric aerosol climatology for the continental areas of the world. This is to be achieved by combining archived meteorological data observations, aerosol monitoring data, and general knowledge on the properties and behavior of aerosols. Exploration of meteorological data is a data intensive project. In this report database concepts and available data handling and manipulation techniques are described. Novel data handling and exploration facilities were applied to the meteorological data. Rationale and specific methods used to analyze European visibility data are presented. GRA N91-12395# Naval Postgraduate School, Monterey, CA. William A. Sheehan Dec. 1989 124 p (AD-A225310) Avail: NTIS HC/MF A06 CSCL 12/7 There has been a tremendous growth in recent years in the use of data base management systems (DBMS) throughout the world. This has lead to efforts to increase the effectiveness and efficiency of systems designed to create and maintain large databases. The traditional approach has been to select a data model and its associated model-based data language and implement a database system based on that single model. The multi-model and multi-lingual database system (MM and MLDS) was designed to increase the functionality of database systems by allowing the use of multiple data models and several model-based languages on a single system. With this approach, the system could support a heterogeneous collection of databases, each based on the model most appropriate for the individual application requirements. The current implementation of MM and MLDS is restricted in cross-model accessing the available databases. This thesis is part of the effort to remove these restrictions, thereby allowing the databases based on given models to be accessed by database languages associated with different models. The goal of this thesis is to further increase the functionality of MM and MLDS by permitting a user knowledgeable only in a hierarchical-based data language (DL/I) to access and manipulate information in a network database, while strictly maintaining the integrity of the network model. GRA N91-12396# Maryland Univ., College Park. Inst. for Advanced A DISTRIBUTED USER INFORMATION SYSTEM Current user information database technology within the DARPA/NSF Internet is adequate to deal with hundreds of hosts and a few thousand users. However, recent size estimates of the Internet indicate that its host population is now closer to one hundred thousand machines, and that its user population numbers around one million users. The current centralized technology cannot scale to accommodate such a large information base, and provides no facilities for the distribution or replication of information. This paper presents the design of a distributed, scalable user information database. GRA increase file accuracy, and increase access to file information. Alternatives using current document storage technology were analyzed. A PC-based optical document storage and retrieval system is proposed as the optimum alternative. GRA 83 ECONOMICS AND COST ANALYSIS Includes cost effectiveness studies. No abstracts in this category. 84 LAW, POLITICAL SCIENCE AND SPACE POLICY Includes NASA appropriation hearings; aviation law; space law and policy; international law; international cooperation; and patent policy. No abstracts in this category. 85 URBAN TECHNOLOGY AND TRANSPORTATION Includes applications of space technology to urban problems; technology transfer; technology assessment; and surface and mass transportation. For related information see also 03 Air Transportation and Safety, 16 Space Transportation, and 44 Energy Production and Conversion. N91-12398# Instituto de Pesquisas Espaciais, Sao Jose dos Adriana PrestMattedi Apr. 1990 161 p In PORTUGUESE; ENGLISH summary (INPE-5082-TDL/416) Avail: NTIS HC/MF A08 The Technological Innovation Centers (NITs) are analyzed as a structure which facilitates the interaction between research and production sectors. A theoretical basis was developed in order to understand the development of Brazil's technological policy, the processes of technological innovation and transfer, and some structures of interaction. A study about international experiences and a comparison between them and the NITs are also presented. In the empirical study, nine NITs were analyzed in order to examine their performance. It was observed that the NITS face structural problems and their present situation is far from the initial proposition. Despite these problems the main conclusion is that NITs are a valuable tool acting between technological demand and supply, enhancing the technological innovation. The NITs need to be restructured. Some suggestions are presented in order to increase the performance of the NITS. Author N91-12399# Instituto de Pesquisas Espaciais, Sao Jose dos Campos (Brazil). TECHNOLOGICAL POLES IN BRAZIL: DEVELOPMENT AND NEW DIRECTIONS M.S. Thesis [POLOS TECNOLOGICOS NO BRASIL: DESEMPENHO E NOVOS ENCAMINHAMENTOS] Monica Maria DeMarchi Apr. 1990 163 p In PORTUGUESE; ENGLISH summary (INPE-5081-TDL/415) Avail: NTIS HC/MF A08 The performance of the Technological Poles mechanism and similar structures is analyzed for example science parks. Initially, a literature search about the process of technological innovation and similar experiences in other countries was conducted. Subsequently, information was obtained through three distinct interview procedures to ascertain if Technological Poles are relevant to their region, how this mechanism helps the relation between professionalizing and research institutions with different companies, and how it helps the establishment of enterprises with technological basis. The development of each Pole was studied in conjunction with the factors behind this process. The role of the government was also investigated in each of the cases, and in particular its contribution to the build up of regional scientific and technological competency. Also investigated was the role of entrepreneurs, either science or business oriented. After this analysis some measures were proposed to contribute to the development of the Technological Poles mechanism. Author N91-12400# Concordia Univ., Montreal (Quebec). Centre for RESEARCH ON COMPLEX DECISION MAKING, KNOWLEDGE (Contract MDA903-82-C-0055) (AD-A225447; ARI-RN-90-35) Avail: NTIS HC/MF A03 CSCL 12/5 This report briefly describes the results of a program of research that focused on the conversion of a new technology into a form that is facile and generally transferable using a network of microprocessors. When the contract was awarded, the choice (at that time a very reasonable choice) of hardware was the 8-bit microprocessor and the Apple II microprocessor, augmented by standard peripheral equipment. The program suites, appropriate to these machines and a Corvus 20 Megabyte Disc, have been delivered, as originally specified. It is true a 16- or 32-bit technology would have been a better choice since obvious limitations and difficulties crop up with a smaller address space. However, the networking paradigm remains viable and may only be replaced by a multitasking system with very sophisticated display and control capabilities to exhibit the power of the systems to any user and render the computing organization transparent, as is required. The deliverables so far noted are CASTE (Course Assembly System and Tutorial Environment), THOUGHTSTICKER, and the Team Decision System (TDS), together with manually and computer-administered versions of a test for learning innovative and conceptual style, SPC2. In addition, documentation, source code, and various other documents are deliverable products. N91-12403*# c18 National Aeronautics and Space Administration. Marshall Space Flight Center, Huntsville, AL. DESIRABLE LIMITS OF ACCELERATIVE FORCES IN A SPACE-BASED MATERIALS PROCESSING FACILITY Robert J. Naumann In its Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 18 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22B There are three categories of accelerations to be encountered on orbiting spacecraft: (1) quasi-steady accelerations, caused by atmospheric drag or by gravity gradients, 10(exp -6) to 10(exp -7) g sub o; (2) transient accelerations, caused by movements of the astronauts, mass translocations, landing and departure of other spacecraft, etc.; and (3) oscillary accelerations, caused by running machinery (fans, pumps, generators). Steady accelerations cause continuing displacements; transients cause time-limited displacements. The important aspect is the area under the acceleration curve, measured over a certain time interval. Note that this quantity is not equivalent to a velocity because of friction effects. Transient motions are probably less important than steady accelerations because they only produce constant displacements. If the accelerative forces were not equal and opposite, the displacement would increase with time. A steady acceleration will produce an increasing velocity of a particle, but eventually an equilibrium value will be reached where drag and acceleration forces are equal. From then on, the velocity will remain constant, and the displacement will increase linearly with time. Author (Contract NAS8-36122) (NASA-CP-3088; M-639; NAS 1.55:3088) Avail: NTIS HC/MF A99 CSCL 03A This workshop provides a comprehensive overview of the work and status of each of these areas to provide a basis for establishing a systematic approach to the challenge of avoiding these difficulties during the Space Station era of materials experimentation. The discussions were arranged in the order of: the scientific understanding of the requirements for a micro-gravity environment, a history of acceleration measurements on spacecraft, the state ACCELERATION EFFECTS OBSERVED IN OPTICAL DATA TAKEN IN SPACELAB 3 FES c74 James Trolinger, Ravindra Lal (Alabama A & M Univ., Huntsville.), and Rudy Ruff In its Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 25 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 20F Optical instrumentation in the Fluids Experiment System (FES) is briefly described. Samples of the data produced by the schlieren and holography systems during the Spacelab 3 flight are then J. Iwan D. Alexander and Charles A. Lundquist (Alabama Univ., The primary reason for conducting many materials science experiments in space is to minimize or eliminate undesirable effects that might result owing to convective motions in fluids that are driven by buoyancy effects. Of particular concern are the low frequency accelerations caused by the Earth's gravity gradient field, spacecraft attitude motions, and atmospheric drag. In order to gain a limited understanding of the effects of these accelerations, researchers calculated the Stokes' motion of a spherical particle in a fluid for various types of spacecraft attitudes. Researchers assessed the effect of slowly rotating the experimental system relative to the spacecraft in order to reduce the rate at which the particles accumulate against the container wall. Author N91-12407*# Deutsche Forschungs- und Versuchsanstalt fuer C29 H. Hamacher, U. Merbold (European Space Agency, Paris, France), and R. Jilg In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 24 P Previously announced in IAA as A87-15978 (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22A Some characteristic features and results of D1 microgravity measurements are discussed as performed in the Material Science Double Rack (MSDR) and the Materials Science Double Rack for Experiment Modules and Apparatus (MEDEA). Starting with a brief review of the main potential disturbances, the payload aspects of interest to the analysis and the accelerometer measuring systems are described. The microgravity data are analyzed with respect to selected mission events such as thruster firings for attitude control, operations of Spacelab experiment facilities, vestibular experiments and crew activities. The origins are divided into orbit, vehicle, and experiment induced perturbations. It has been found that the microgravity-environment is dictated mainly by payload-induced perturbations. To reduce the microgravity-level, the design of some experiment facilities has to be improved by minimizing the number of moving parts, decoupling of disturbing units from experiment facilities, by taking damping measures, etc. In addition, strongly disturbing experiments and very sensitive investigations should be performed in separate mission phases. Author Edward Bergmann In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 16 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22A As the number of acceleration sensitive experiments to be carried on each Shuttle or Space Station mission increases, the requirement for either low-g environment or for accelerometry at each experiment location also increases. Preflight planning of such experiments in the past has not always included detailed analyses of the acceleration environment at the experiment location that had a serious impact on the experiment. Careful modeling of the mission activities and their effect on the experiment in many cases would have been beneficial to these experiments. In some cases, the experiment was not comprised, but insufficient instrumentation was available onboard to directly measure accelerations at the experiment location. The type of preflight modeling available to assist in experiment design and mission integration is described, as well as the use of that tool postflight to enhance flight data when sensors are not ideally suited to experiment analysis. Examples of recent shuttle flight experiments are presented. Author N91-12410*# BGB, Inc., Huntsville, AL. Gary Arnett In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 46 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22A The Fluids Experiment System (FES) flown aboard Spacelab 3 contained a Miniature Electrostatic Accelerometer (MESA). This accelerometer was purchased from Bell Aerospace, Textron and had three range (auto switching), bidirectional, three orthogonal axis capability. BGB, Inc. is in the process of examining the total mission data from this instrument. From these data, areas of interest are identified and related back to mission events. The basic format of the data for the total mission is root mean square (RMS), with two hours per plot. N91-12411*# Teledyne Brown Engineering, Huntsville, AL. MSL-2 ACCELEROMETER DATA RESULTS Author c19 Fred Henderson In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 29 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B The Materials Science Laboratory-2 (MSL-2) mission flew the Marshall Space Flight Center-developed Linear Triaxial Accelerometer (LTA) on the Space Transportation System (STS) 61-C Shuttle mission launched January 21, 1986. Flight data were analyzed to verify the quietness of the MSL carrier and to characterize the acceleration environment for future MSL users. The MSL was found to introduce no significant experiment acceleration; and the effects of crew treadmill exercise, Orbiter vernier engine firings, and other routine flight occurrences were established. The LTA was found to be well suited for measuring nominal to very quiet STS acceleration levels at frequencies below 50 Hz. Special processing was used to examine the low-frequency spectrum and to establish the effective rms amplitude associated with dominant frequencies. Author N91-12412*# Jet Propulsion Lab., California Inst. of Tech., c19 David Sonnabend In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 12 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B In principle, gravity gradiometers are immune to the effects of acceleration and vibrations. In real instruments, scale factor errors and structural compliance lead to undesired instrument outputs. Described here are the instruments and the fundamental sources of the problems, a calculation of the magnitude of the effects, a demonstration of the need for isolation in the Shuttle (indeed, almost any spacecraft), and the Jet Propulsion Laboratory eddy current isolation technique and its current development status. Author N91-12413*# Textron Bell Aerospace Co., Belmont, CA. THE MESA ACCELEROMETER FOR SPACE APPLICATION €19 William G. Lange and Robert W. Dietrich In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 28 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B An electrostatically suspended proof mass in the Miniature Electrostatic Accelerometer (MESA) is used to measure acceleration in the submicro-g range. Since no fixed mechanical suspension (such as springs or strings) is used, the constrainment scaling can be changed electrically after being placed in orbit. A single proof mass can sense accelerations in three axes simultaneously. It can survive high-g pyrotechnic-generated shocks and launch environments while unpowered. N91-12414*# Payload Systems, Inc., Wellesley, MA. Author C19 Byron Lichtenberg In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 18 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B Microgravity investigators are interested in enhancing the capabilities and improving the information return from accelerometers used in microgravity research. In addition to improving the accelerometer sensor, efforts should be directed towards using recent advances in microprocessor technology and system design techniques to improve sensor calibration and temperature compensation, online data display and analysis, and data reduction and information storage. Results from the above areas of investigation should be combined in an integrated design for a spaceflight microgravity accelerometer package. Author Honeywell, Inc., Minneapolis, MN. Systems and N91-12415*# H. J. Paik In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 14 p (For primary document see N91-12401 03-88) A new superconducting accelerometer, capable of measuring both linear and angular accelerations, is under development at the University of Maryland. A single superconducting proof mass is magnetically levitated against gravity or any other proof force. Its relative positions and orientations with respect to the platform are monitored by six superconducting inductance bridges sharing a single amplifier, called the Superconducting Quantum Interference Device (SQUID). The six degrees of freedom, the three linear acceleration components and the three angular acceleration components, of the platform are measured simultaneously. In order to improve the linearity and the dynamic range of the instrument, the demodulated outputs of the SQUID are fed back to appropriate levitation coils so that the proof mass remains at the null position for all six inductance bridges. The expected intrinsic noise of the instrument is 4 x 10(exp -12)m s(exp -2) Hz(exp -1/2) for linear acceleration and 3 x 10(exp -11) rad s(exp -2) Hz(exp -1/2) for angular acceleration in 1-g environment. In O-g, the linear acceleration sensitivity of the superconducting accelerometer could be improved by two orders of magnitude. The design and the operating principle of a laboratory prototype of the new instrument is discussed. Author Theodore L. Chase In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 20 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B The primary objective of the Space Acceleration Measurement Systems (SAMS) project is to provide an acceleration measurement system capable of serving a wide variety of space experiments. The design of the system being developed under this project takes into consideration requirements for experiments located in the middeck, in the orbiter bay, and in Spacelab. In addition to measuring, conditioning, and recording accelerations, the system will be capable of performing complex calculations and interactive control. The main components consist of a remote triaxial optical storage device. In operation, the triaxial sensor head produces output signals in response to acceleration inputs. These signals are preamplified, filtered and converted into digital data which is then transferred to optical memory. The system design is modular, facilitating both software and hardware upgrading as technology advances. Two complete acceleration measurement flight systems will be build and tested under this project. Author N91-12418*# Teledyne Geotechnical, Dallas, TX. ACQUISITION AND ANALYSIS OF ACCELEROMETER DATA C19 Keith R. Verges In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 32 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B Acceleration data reduction must be undertaken with a complete understanding of the physical process, the means by which the data are acquired, and finally, the calculations necessary to put the data into a meaningful format. Discussed here are the acceleration sensor requirements dictated by the measurements desired. Sensor noise, dynamic range, and linearity will be determined from the physical parameters of the experiment. The digitizer requirements are discussed. Here the system from sensor to digital storage medium will be integrated, and rules of thumb for experiment duration, filter response, and number of bits are explained. Data reduction techniques after storage are also discussed. Time domain operations including decimating, digital filtering, and averaging are covered, as well as frequency domain methods, including windowing and the difference between power and amplitude spectra, and simple noise determination via coherence analysis. Finally, an example experiment using the Teledyne Geotech Model 44000 Seismometer to measure from 1 Hz to 10(exp -6) Hz is discussed. The sensor, data acquisition system, and example spectra are presented. Author N91-12419*# Applied Technology Associates, Inc., Albuquerque, NM. CHARACTERIZING PERFORMANCE OF ULTRA-SENSITIVE ACCELEROMETERS c19 Henry Sebesta In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 27 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 14B An overview is given of methodology and test results pertaining to the characterization of ultra sensitive accelerometers. Two issues are of primary concern. The terminology ultra sensitive accelerometer is used to imply instruments whose noise floors and resolution are at the state of the art. Hence, the typical approach of verifying an instrument's performance by measuring it with a yet higher quality instrument (or standard) is not practical. Secondly, it is difficult to find or create an environment with sufficiently low background acceleration. The typical laboratory acceleration levels will be at several orders of magnitude above the noise floor of the most sensitive accelerometers. Furthermore, this background must be treated as unknown since the best instrument available is the one to be tested. A test methodology was developed in which two or more like instruments are subjected to the same but unknown background acceleration. Appropriately selected spectral analysis techniques were used to separate the sensors' output spectra into coherent components and incoherent components. The coherent part corresponds to the background acceleration being measured by the sensors being tested. The incoherent part is attributed to sensor noise and data acquisition and processing noise. The method works well for estimating noise floors that are 40 to 50 dB below the motion applied to the test accelerometers. The accelerometers being tested are intended for use as feedback sensors in a system to actively stabilize an inertial guidance component test platform. Author Owen K. Garriott In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 2 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22A Manned spacecraft will never be free of acceleration perturbations due to necessary motions of crewmembers. However, in most cases, the perturbations can be minimized or even isolated from sensitive experiments when required. The principal disturbances and methods of isolation are described. As the crew moves about the spacecraft, no external forces are applied and the average acceleration remains near zero. External force will be exerted when jets are fired for spacecraft attitude control or translation, and these must be transferred to the microgravity experiments. Transitory acceleration and vibration are produced by crew and equipment. The most significant on Orbiter have been wall push-offs used for body translation within the spacecraft, the exercise conducted on a treadmill within the middeck area, closing doors of stowage compartments and the vibration of some machinery, such as a sample centrifuge. For short periods of perhaps a few minutes, crew and equipment motion can be largely inhibited, but not for much longer intervals. It may be necessary to mount especially sensitive experiments on an isolation table, which can greatly reduce the acceleration transferred to the experiment. Either weak mechanical springs or, even better, a computer-controlled electromagnetic suspension can be used to effectively insulate the table from vibration at frequencies above about 0.01 Hz. Another option is to free-float an experiment table within the spacecraft. All of the above-mentioned perturbations can be eliminated for some minutes if the entire experiment package is allowed to free-float within the spacecraft until a wall contact is made. Package acceleration levels should be maintainable below 10(exp -8) g sub o in this way. Author Walter Knabe and Charles R. Baugher, ed. (National Aeronautics and Space Administration. Marshall Space Flight Center, Huntsville, AL.) In NASA, Marshall Space Flight Center, Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 1 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22A In view of the decisive importance of a disturbance-free environment on the Space Station, and on other orbital systems, for materials processing experiments, a theoretical and semi-experimental analysis of the acceleration environment to be expected on large orbiting spacecraft was undertaken. A unified model of such spacecraft cannot be established; therefore, a number of sub-models representing major components of typical large spacecraft must be investigated. In order to obtain experimental data of forces, a typical spacecraft - an engineering model of the Spacelab - was suspended on long ropes in a high-bay hanger, and equipped with a number of accelerometers. Active components on the Spacelab (fans, pumps, air conditioners, valves, levers) were operated, and astronautics moved boxes, drawers, sleds, and their own bodies. Generally speaking, the response of the Spacelab structure was very similar to the environment measured on Spacelabs SL-1, SL-2, and D-1. At frequencies in the broad range between 1 and about 100 Hz, acceleration peaks reached values of 10(exp -3) and 10(exp -2) g sub o, and even higher. Author LOW-g PAYLOAD PLACEMENT CONSTRAINTS FOR SPACE STATION C18 Anita S. Carpenter and Stanley N. Carroll In its Measurement and Characterization of the Acceleration Environment on Board the Space Station Aug. 1990 14 p (For primary document see N91-12401 03-88) Avail: NTIS HC/MF A99 CSCL 22B Payloads onboard the Space Station will be subjected to a steady state acceleration level dominated by gravity gradient and aerodynamic drag forces. The g-level due to gravity gradient forces depends on the payload location relative to the center of mass, whereas the g-level due to aerodynamic drag may be assumed nearly constant throughout the Space Station. The vector of acceleration due to aerodynamic drag can always be broken down into three orthogonal components, in the direction opposite to the velocity vector, along the local vertical, and perpendicular to the orbit plane. It will be shown that the gravity gradient term has two components, which are orthogonal to one another. One component is along the local vertical and the other is perpendicular to the orbit plane. Thus, the combination of all components form an orthogonal triad of vectors. Addressed here are the payload location constraints to satisfy the requirements of 1 micro-g. The permissible locations are within an open-ended tube having an elliptical cross section, which is aligned with the velocity vector and centered on the system center of mass. Author |