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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Remote sensing data processing - Two years ago, today, and two years from today

Certain technical problems arising in the recent past (1975) in the field of the processing of remote sensing data are reviewed including approaches to the analysis of Landsat MSS data and technical difficulties which must be overcome to achieve operational data processing. The current status of remote sensing data processing is then examined with emphasis on such current technical issues as training selection and labeling, sampling schemes and classification and mensuration. Hardware projections are made for the near future (1979) relative to the development of remote sensing data processing.

Holmes, Q. A.↗
NASA NTRS1977

A survey of SAR image-formation processing for earth resources applications

Currently there is considerable interest in active microwave sensors for earth resources applications. A particular example is the Seasat-A radar. However, to obtain spatial resolutions comparable to optical sensors at radar frequencies, sophisticated image formation processing techniques must be applied to the raw data. This paper briefly compares processing requirements for non-coherent optical and coherent radar imaging systems, and then discusses the image formation processing requirements for synthetic aperture radar (SAR) systems. Both optical and digital techniques are addressed, and examples of hardware and imagery for each processing technique are presented.

Bayma, R. W.↗
NASA NTRS1977

Thermodynamic processes induced by coherent radiation

It is shown by quantum statistics that under certain stated conditions the entropy of coherent radiation is zero and it is still negligible for multimode laser operation. This makes possible gas kinetic processes which, to a small extent, have already been observed or even utilized, but which can be greatly enhanced by an optimized choice of molecular structures and radiation conditions. Radiative cooling of gases is discussed in detail. The conditions for maximum heat withdrawal are derived, and it is proposed that the processes of cooling and relaxation heating can be sufficiently separated in time to achieve certain effects and thermodynamic cycles. One of these is the complete conversion, possible in principle, of coherent radiation into work. This concept is based on a heat pump process followed by heat-to-work conversion, the heat rejected being just equal to that withdrawn by radiation. The conditions for complete conversion turn out to be the same as for maximum heat withdrawal. The feasibility of these processes depends on the degree to which practical conditions can be met, and on the validity of certain assumptions which have to await experimental verification.

Garbuny, M.↗
NASA NTRS1978

A study of 'onboard' data processing for typical astrophysics payloads

The data, signal flow, and ground processing requirements for a typical set of X-ray and gamma-ray experiments were examined. A set of algorithms for ground processing were derived and these were taken as requirements imposed on 'onboard' spacecraft computers. Five types of CPU microprocessors were evaluated and compared with one another to determine the degree to which the data processing could be performed onboard the spacecraft. These included the NASA Standard Spacecraft Computer (NSSC-1), the Z-80, a Z-80 augmented with an auxiliary fast multiply chip, and an advanced augmented Z-80 with virtually unlimited memory. These CPU were investigated when used in a centralized mode, an experiment dedicated mode, and a hybrid of the first two modes. It was found that the use of onboard processing can significantly reduce downlink data rates for typical payloads, and may lead to greater efficiency of operation. Quantitative data for gamma-ray and X-ray payloads will be presented, and the results of the analysis discussed.

Stout, C. M.↗
NASA NTRS1978

Analysis of complex decisionmaking processes

The analysis of corporate decisionmaking processes related to major system developments is unusually difficult because of the number of decisionmakers involved in the process and the long development cycle. A method for analyzing such decision processes is developed and illustrated through its application to the analysis of the commercial jet engine development process. The method uses interaction matrices as the key tool for structuring the problem, recording data, and analyzing the data to establish the rank order of the major factors affecting development decisions. In the example, the use of interaction matrices permitted analysts to collect and analyze approximately 50 factors that influenced decisions during the four phases of the development cycle, and to determine the key influencers of decisions at each development phase. The results of this study indicate that the cost of new technology installed on an aircraft is the prime concern of the engine manufacturer.

Hill, J. D.↗
NASA NTRS1977

Annual Symposium on Machine Processing of Remotely Sensed Data, 4th, Purdue University, West Lafayette, Ind., June 21-23, 1977, Proceedings

Papers are presented on a variety of techniques for the machine processing of remotely sensed data. Consideration is given to preprocessing methods such as the correction of Landsat data for the effects of haze, sun angle, and reflectance and to the maximum likelihood estimation of signature transformation algorithm. Several applications of machine processing to agriculture are identified. Various types of processing systems are discussed such as ground-data processing/support systems for sensor systems and the transfer of remotely sensed data to operational systems. The application of machine processing to hydrology, geology, and land-use mapping is outlined. Data analysis is considered with reference to several types of classification methods and systems.

Morrison, D. B.↗
NASA NTRS1979

Silicon materials task of the low cost solar array project. Phase 3: Effect of impurities and processing on silicon solar cells

The 13th quarterly report of a study entitled an Investigation of the Effects of Impurities and Processing on Silicon Solar Cells is given. The objective of the program is to define the effects of impurities, various thermochemical processes and any impurity-process interactions on the performance of terrestrial silicon solar cells. The Phase 3 program effort falls in five areas: (1) cell processing studies; (2) completion of the data base and impurity-performance modeling for n-base cells; (3) extension of p-base studies to include contaminants likely to be introduced during silicon production, refining or crystal growth; (4) anisotropy effects; and (5) a preliminary study of the permanence of impurity effects in silicon solar cells. The quarterly activities for this report focus on tasks (1), (3) and (4).

Hopkins, R. H.↗
NASA NTRS1978

Analysis and evaluation of process and equipment in tasks 2 and 4 of the Low Cost Solar Array project

Several experimental and projected Czochralski crystal growing process methods were studied and compared to available operations and cost-data of recent production Cz-pulling, in order to elucidate the role of the dominant cost contributing factors. From this analysis, it becomes apparent that substantial cost reductions can be realized from technical advancements which fall into four categories: an increase in furnace productivity; the reduction of crucible cost through use of the crucible for the equivalent of multiple state-of-the-art crystals; the combined effect of several smaller technical improvements; and a carry over effect of the expected availability of semiconductor grade polysilicon at greatly reduced prices. A format for techno-economic analysis of solar cell production processes was developed, called the University of Pennsylvania Process Characterization (UPPC) format. The accumulated Cz process data are presented.

Goldman, H.↗
NASA NTRS1978

Silicon Solar Cell Process Development, Fabrication and Analysis

Ribbon to Ribbon (RTR) solar cells processed from polycrystalline feedstock showed maximum AMO efficiency of 5.6%. Solar cells from single crystalline feedstock showed slightly higher efficiency than those from polycrystalline feedstock, indicating maximum efficiency of about 6.6% with SiO AR coating. Single crystalline control cells gave 11-12% AMO efficiencies demonstrating that the poor performance of the RTR solar was due to the low quality of material itself. Dendritic web solar cells from the standard process showed maximum AMO efficiency of 9.8% while efficiency of control solar cells were around 11-12%. Web solar cells from back surface field (BSF) process indicated maximum AMO efficiency of 10.9%. Some improvement in open circuit voltage was noticed from the BSF process. Small light spot scanning experiments were carried out on the solar cells from Wacker Silso, EFG, RTR, and dendritic web ribbons. Photoresponse results provided information on localized cell performance and grain size in polycrystalline material, and agreed quite well with the cell performance data, such as efficiency, minority carrier diffusion length, and spectral response.

Yoo, H. I.↗
NASA NTRS1979

Analysis and Evaluation of Processes and Equipment in Tasks 2 and 4 of the Low-cost Solar Array Project

To facilitate the task of objectively comparing competing process options, a methodology was needed for the quantitative evaluation of their relative cost effectiveness. Such a methodology was developed and is described, together with three examples for its application. The criterion for the evaluation is the cost of the energy produced by the system. The method permits the evaluation of competing design options for subsystems, based on the differences in cost and efficiency of the subsystems, assuming comparable reliability and service life, or of competing manufacturing process options for such subsystems, which include solar cells or modules. This process option analysis is based on differences in cost, yield, and conversion efficiency contribution of the process steps considered.

Wolf, M.↗
NASA NTRS1979

Development of Pulsed Processes for the Manufacture of Solar Cells

The development status of the process based upon ion implantation for the introduction of junctions and back surface fields is described. A process sequence is presented employing ion implantation and pulse processing. Efforts to improve throughout and descrease process element costs for furnace annealing are described. Design studies for a modular 3,000 wafer per hour pulse processor are discussed.

Source record↗
NASA NTRS1979

The evolution of apparatus for materials processing on Skylab

The following topics are discussed: (1) the inception of space processing; (2) earth-based experimental activities prior to Skylab (drop tower and research aircraft experiments); (3) preliminary experiments in space (Apollo and sounding rocket experiments); and (4) Skylab experimental facilities. Apparatus for contained materials processing; for brazing in space; and containerless processing are presented and discussed. The Skylab materials processing system and miscellaneous design considerations are also discussed.

Source record↗
NASA NTRS1978

Efficient payload processing - The opposite side of frequent Space Shuttle launches

An overview is presented of the processing cycles of horizontally integrated and vertically integrated Shuttle payloads at the Kennedy Space Center. Attention is given to the integration of these payloads into Shuttle-ready cargos and the installation of the cargo into the Orbiter. Diagrams are presented of: (1) Shuttle processing flow at KSC, (2) payload processing flow, (3) typical items of multimission support equipment, (4) primary items of checkout equipment, (5) payload ready for transfer into the canister for vertical processing, and (6) the rotating service structure retracted to receive the payload canister.

Scherer, L. R.↗
NASA NTRS1978

On-board data processing for the IRAS telescope system

Onboard data processing has been developed for the Infrared Astronomical Satellite (IRAS) telescope system to effectively utilize the RF bandwidth and minimize the ground-data processing costs. Use of filtering techniques, data deglitching circuits, and data encoding algorithms are combined with a microprocessor-controlled telescope system to achieve a system dynamic range of 100,000 with a noise equivalent flux density of no less than 10 to the minus 19th W/sq cm. Extraneous data, e.g., noise due to radiation hits, will be removed prior to transmission, thereby optimizing ground-data processing for the highest sensitivity and reliability. Simulation results are presented which demonstrate the advantages gained through the use of onboard data processing and illustrate the possible merging of these techniques with an array for the future evolution of 'smart' sensors.

Lum, H.↗
NASA NTRS1978

Impact of advanced onboard processing concepts on end-to-end data system

An investigation is conducted of the impact of advanced onboard data handling concepts on the total system in general and on ground processing operations, such as those being performed in the central data processing facility of the NASA Goddard Space Flight Center. In one of these concepts, known as the instrument telemetry packet (ITP) system, telemetry data from a single instrument is encoded into a packet, along with other ancillary data, and transmitted in this form to the ground. Another concept deals with onboard temporal registration of image data from such sensors as the thematic mapper, to be carried onboard the Landsat-D spacecraft in 1981. It is found that the implementation of the considered concepts will result in substantial simplification of the ground processing element of the system. With the projected tenfold increase in the data volume expected in the next decade, the introduction of ITP should keep the cost of the ground data processing function within reasonable bounds and significantly contribute to a more timely delivery of data/information to the end user.

Sos, J. Y.↗
NASA NTRS1979

Theory of molecular rate processes in the presence of intense laser radiation

The present paper deals with the influence of intense laser radiation on gas-phase molecular rate processes. Representations of the radiation field, the particle system, and the interaction involving these two entities are discussed from a general rather than abstract point of view. The theoretical methods applied are outlined, and the formalism employed is illustrated by application to a variety of specific processes. Quantum mechanical and semiclassical treatments of representative atom-atom and atom-diatom collision processes in the presence of a field are examined, and examples of bound-continuum processes and heterogeneous catalysis are discussed within the framework of both quantum-mechanical and semiclassical theories.

George, T. F.↗
NASA NTRS1978

Processing by data and program blocks

A processing system is presented that implements simultaneously the efficiency of the special-purpose processor and the total applicability of the general-purpose computer - characteristics commonly thought of as being mutually exclusive. This is achieved through specializing the machine by programming the hardware structure, rather than by adding software systems to it. Data are organized in circulating pages which form a multiplicity of local dynamic memories for each process. Programs are made up of modules, each describing a transient special-purpose machine. A characteristic of this approach is that the processes are data-driven, rather than program-driven. The programming language presents significant flexibility and efficiency in modeling certain classes of problems, and it may be of interest as an implementation model in a broader context. Applications to real-time processing of radar signals are reported. The relevance of characteristics of this system to problems in multiprogramming and multiprocessing systems is discussed.

Schaffner, M. R.↗
NASA NTRS1979

Massively parallel information processing systems for space applications

NASA is developing massively parallel systems for ultra high speed processing of digital image data collected by satellite borne instrumentation. Such systems contain thousands of processing elements. Work is underway on the design and fabrication of the 'Massively Parallel Processor', a ground computer containing 16,384 processing elements arranged in a 128 x 128 array. This computer uses existing technology. Advanced work includes the development of semiconductor chips containing thousands of feedthrough paths. Massively parallel image analog to digital conversion technology is also being developed. The goal is to provide compact computers suitable for real-time onboard processing of images.

Schaefer, D. H.↗