A data combination method for postflight trajectory analysis.
Trajectory measurement errors for powered spacecraft using matrix analysis
SPACECRAFT TRAJECTORY↗
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Results for “methods: data analysis”
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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A new method of analysis of sampled-data control systems.
Sampled data control system analysis, determining gain margin in unsampled loops
DATA CONTROL SYSTEM↗
Measurements of the spectrum of galactic electrons at very high energies
A counter telescope has been exposed in three balloon flights in 1970 to measure the flux and energy spectrum of cosmic ray electrons between 10 and 1000 GeV. This instrument has been modified by incorporating a large area CsI crystal as well as highly efficient time of flight circuitry, and was flown again twice during 1972. The methods of data analysis are based on extensive accelerator calibrations at SLAC. The resulting electron spectrum fits well to a single power law with an index (gamma) equal to 2.66 over the whole energy region. No obvious steepening can be observed, although statistical uncertainties prohibit definite claims beyond 250 GeV.
Mueller, D.↗
Far Infrared Spectroscopy of H II Regions
The far infrared spectra of H II regions are investigated. A liquid helium cooled grating spectrometer designed to make observations from the NASA Lear Jet is described along with tests of the instrument. The observing procedure on the Lear Jet telescope is described and the method of data analysis is discussed. Results are presented from a search for the (O III) 88.16 micron line. An upper limit on the emission in this line is obtained and line detection is described. Results are compared to theoretical predictions, and future applications of fine structure line observations are discussed. Coarse resolution results are given along with calibration problems. The spectra obtained are compared to models for dust emission.
Ward, D. B.↗
Methods of investigation in space biology and medicine, transmission of biomedical data
Methods for in-flight monitoring of the cardiovascular system, respiratory system, vestibular system, central nervous system, and the musculoskeletal systems are described. Methods of data analysis are also discussed.
Bayevskiy, R. M.↗
Methods for data reduction and loads analysis of Space Shuttle Solid Rocket Booster model water impact tests
The methodology used to predict full scale space shuttle solid rocket booster (SRB) water impact loads from scale model test data is described. Tests conducted included 12.5 inch and 120 inch diameter models of the SRB. Geometry and mass characteristics of the models were varied in each test series to reflect the current SRB baseline configuration. Nose first and tail first water entry modes were investigated with full-scale initial impact vertical velocities of 40 to 120 ft/sec, horizontal velocities of 0 to 60 ft/sec., and off-vertical angles of 0 to plus or minus 30 degrees. The test program included a series of tests with scaled atmospheric pressure.
Source record↗
Data processing/display design for the space shuttle/spacelab Electromagnetic Environment Experiment (EEE)
Methods for data analysis, data compression including universal coding, storage and retrieval on random access storage devices, and display were developed and implemented on the GSFC Interdata computer. The original 64 bit per frequency band representation was reduced to 10 bits through source coding/universal coding, a compression ratio of 6.4, prior to storage. Rapid encoding/decoding was achieved by the algorithms used so that rapid random access is retained.
Davisson, L. D.↗
High-energy cosmic-ray electrons - A new measurement using transition-radiation detectors
A new detector for cosmic-ray electrons, consisting of a combination of a transition-radiation detector and a shower detector, has been constructed, calibrated at accelerator beams, and exposed in a balloon flight under 5 g/sq cm of atmosphere. The design of this instrument and the methods of data analysis are described. Preliminary results in the energy range 9-300 GeV are presented. The energy spectrum of electrons is found to be significantly steeper than that of protons, consistent with a long escape lifetime of cosmic rays in the galaxy.
Hartmann, G.↗
On the physical reality of the millisecond bursts in Cygnus X-1 - Bursts and shot noise
The method of data analysis used to interpret the millisecond temporal structure of Cyg X-1 is discussed. In particular, the effects produced by the shot-noise variability of this source, which occurs on time scales of about 0.5 s, are examined. Taking into account the recent discovery that only about 30% of the flux may be in the shots, it is found that spurious 'millisecond bursts' will be detected. A comparison of the properties of these bursts with currently published experimental data is performed.
Weisskopf, M. C.↗
Executive summary of Aircraft Icing Specialists Workshop
In a period of escalating development costs for new aircraft, there is growing interest in a renewed and coordinated icing research effort to achieve an updating or modernization of each aspect of the technological issues that are involved. This includes the data base, analysis methods, test techniques, and test facilities.
Beheim, M. A.↗
Video detection and analysis techniques of transient astronomical phenomena
Low-light-level television systems have been utilized to gain information on meteors, aurorae, and other faint, transient astronomical phenomena. Such phenomena change not only their position as a function of time, but also their photometric and spectral characteristics in as little as 1/60 second, thus requiring unique methods of analysis. Data observed with television systems and recorded on video tape have been analyzed with a system utilizing both analog and digital techniques. Both off-the-shelf equipment and inhouse developments are used to isolate sequences of moving images and to store them in a form suitable for photometric and spectral reduction. Current emphasis of the analysis effort is directed at the measurement of the first-order emission lines of meteor spectra, the results of which will yield important compositional information concerning the nature of the impinging meteoroid.
Clifton, K. S.↗
Precise relative location estimation from satellite laser observations
Laser data from the Greenbelt, Bermuda, and Grand Turk Island tec tracking stations, and from observation at Patrick Air Force Base were used in an experiment to determine precise inter-station baselines and relative heights in short orbital arcs of no more than 12 minutes duration. The relative locations obtained are sensitive to reasonable variations in the gravity field to less than 15 cm in inter-station baseline and less than 35 cm in relative height. The formal standard deviations for range measurements at the observed 7 cm noise level are less than 10 cm for either baseline or relative height determinations from the twenty-arc combination solution. The method of data analysis is described, the baseline and relative height results are presented, and gravity model dependence is considered.
Dunn, P. J.↗
Development of basic theories and techniques for determining stresses in rotating turbine or compressor blades
A method for measuring in-plane displacement of a rotating structure by using two laser speckle photographs is described. From the displacement measurements one can calculate strains and stresses due to a centrifugal load. This technique involves making separate speckle photographs of a test model. One photograph is made with the model loaded (model is rotating); the second photograph is made with no load on the model (model is stationary). A sandwich is constructed from the two speckle photographs and data are recovered in a manner similar to that used with conventional speckle photography. The basic theory, experimental procedures of this method, and data analysis of a simple rotating specimen are described. In addition the measurement of in-plane surface displacement components of a deformed solid, and the application of the coupled laser speckle interferometry and boundary-integral solution technique to two dimensional elasticity problems are addressed.
Chien, C. H.↗
Remote sensing applied to agriculture: Basic principles, methodology, and applications
The general principles of remote sensing techniques as applied to agriculture and the methods of data analysis are described. the theoretical spectral responses of crops; reflectance, transmittance, and absorbtance of plants; interactions of plants and soils with reflectance energy; leaf morphology; and factors which affect the reflectance of vegetation cover are dicussed. The methodologies of visual and computer-aided analyses of LANDSAT data are presented. Finally, a case study wherein infrared film was used to detect crop anomalies and other data applications are described.
Dejesusparada, N.↗
Comparison of spur gear efficiency prediction methods
The predictions of five spur-gear efficiency calculation methods were compared with three sets of test data using different gear geometries. The data and the analysis methods were limited to jet lubricated, ground, spur gears. The data covered a range in pitch line velocity to 1 to 20 m/sec (200 to 4000 ft/min) and K-load factor range of 17 to 1600.
Anderson, N. E.↗
Ultrasonic wave propagation in two-phase media: Spherical inclusions
The scattering theory, recently developed via the extended method of equivalent inclusion, is used to study the propagation of time-harmonic waves in two-phase media of elastic matrix with randomly distributed elastic spherical inclusion materials. The elastic moduli and mass density of the composite medium are determined as functions of frequencies when given properties and concentration of the spheres and the matrix. Velocity and attenuation of ultrasonic waves in two-phase media are determined for cases of distributed spheres and localized damage. An averaging theorem that requires the equivalence of the strain energy and the kinetic energy between the effective medium and the original matrix with spherical inhomogeneities is employed to derive the effective moduli and mass density. The functional dependency of these quantities upon frequencies and concentration provides a method of data analysis in ultrasonic evaluation of material properties. Numerical results or moduli, velocity and/or attenuation as functions of concentration of inclusion material, or porosity, are graphically displayed.
Fu, L. S.↗
Sydney Chapman and his early studies of magnetic disturbances
Sydney Chapman's 1918 and 1927 papers on magnetic storms and disturbances of lesser intensity and the background in which these papers were prepared are described from a historical point of view. In spite of the greatly limited availability of observations, the average characteristics of the magnetic variations during these disturbances derived by Chapman are remarkably accurate. An attempt is made to portray Chapman's rigorous and conscientious method of data analysis.
Sugiura, M.↗
Ultrasonic wave propagation in two-phase media - Spherical inclusions
The scattering theory, recently developed via the extended method of equivalent inclusion, is used to study the propagation of time-harmonic waves in two-phase media of elastic matrix with randomly distributed elastic spherical inclusion materials. The elastic moduli and mass density of the composite medium are determined as functions of frequencies when given properties and concentration of the spheres and the matrix. Velocity and attenuation of ultrasonic waves in two-phase media are determined for cases of distributed spheres and localized damage. An averaging theorem that requires the equivalence of the strain energy and the kinetic energy between the effective medium and the original matrix with spherical inhomogeneities is employed to derive the effective moduli and mass density. The functional dependency of these quantities upon frequencies and concentration provides a method of data analysis in ultrasonic evaluation of material properties. Numerical results or moduli, velocity and/or attenuation as functions of concentration of inclusion material, or porosity, are graphically displayed.
Fu, L. S.↗