Arecibo data reduction
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A nonspecific review of theory, correlative date analysis and supporting research and technology is presented. Title pages in some of the following areas are included: (1) magnetosphere boundary observations; (2) venus ionosphere and solar wind interaction; (3) ISEE-C plasma wave investigation, and (4) solar system plasmas.
Definitions, algorithms, and procedures for the reduction of monopropellant thruster measurements to performance parameters are provided. A brief discussion of acquisition and recording systems is also included. Emphasis is placed upon monopropellant hydrazine engines, and some parameters relate specifically to the catalytic decomposition of hydrazine (e.g., percent ammonia dissociation). Performance of other types of monopropellant thrusters may, however, be determined by using procedures similar to those discussed. Two appendixes are included: (1) theoretical performance of monopropellant hydrazine; and (2) calculation of rotational performance.
The paper describes the reduction procedure used for observations of Saturn's rings taken with the International Planetary Patrol Network in 1977. Corrections for atmospheric smearing are determined using an assumed ring model and performed by a two-dimensional Wiener filter developed at JPL's Image Processing Laboratory. These smearing corrections are shown to be consistent with the radial profile of the rings, not just on the major axis of the ring system, but over a range of azimuthal angle.
The methods by which aerodynamic coefficients are determined and discussed. These include: calculations, wind tunnel experiments and experiments in flight for various prototypes of the Alpha Jet. A comparison of obtained results shows good correlation between expectations and in-flight test results.
There are no author-identified significant results in this report.
The burn and burn/explode effects on aircraft structures were examined in a series of fifteen outdoor tests conducted to verify the results obtained in previous burn and explode tests of carbon/graphite composite samples conducted in a closed chamber, and to simulate aircraft accident scenarios in which carbon/graphite fibers would be released. The primary effects that were to be investigaged in these tests were the amount and size distribution of the conductive fibers released from the composite structures, and how these various sizes of fibers transported downwind. The structures included plates, barrels, aircraft spoilers and a cockpit. The heat sources included a propane gas burner and 20 ft by 20 ft and 40 ft by 60 ft JP-5 pool fires. The larger pool fire was selected to simulate an aircraft accident incident. The passive instrumentation included sticky paper and sticky bridal veil over an area 6000 ft downwind and 3000 ft crosswind. The active instrumentation included instrumented meteorological towers, movies, infrared imaging cameras, LADAR, high voltage ball gages, light emitting diode gages, microwave gages and flame velocimeter.
Highlights from the IMP 7 plasma wave experiment are briefly outlined. The measurements in the tail revealed great complexities involving substorms and fireballs and provided insight into the overall dynamics of the magnetosphere. The low levels of magnetic turbulence may be of significance with respect to the development of tearing mode dissipation for reconnection events. The IMP wave observations in the distant magnetosphere boundary region showed that the boundaries were quite diffuse and frequently purely defined. Finally, nearly simultaneous IMP 7 and 8 comparisons were used to achieve an understanding of shock structure and propagation.
A fully automated, interactive system for determining the wavelengths of features in extracted IUE spectra is described. Wavelengths are recorded from video displays of expanded plots of individual orders using a movable cursor, and then corrected for IUE wavelength scale errors. The estimated accuracy of an individual wavelength in the final tabulation is 0.050 A. Such lists are ideally suited for line identification work using the method of wavelength coincidence statistics (WCS). The results of WCS studies of the ultraviolet spectra of the chemically peculiar (CP) stars iota Coronae Borealis and kappa Camcri. Aside from confirming a number of previously reported aspects of the abundance patterns in these stars, the searches produced some interesting, new discoveries, notably the presence of Hf in the spectrum of kappa Camcri. The implications of this work for theories designed to account for anomalous abundances in chemically peculiar stars are discussed.
The investigators published a very large number of space science research papers, and in almost all cases these papers involved correlative multi-spacecraft studies. A tabulation of these research papers is provided. Quarterly progress reports for the second contractual period are included.
The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given.
The characterization of atomized particles generated by various atomizer and the mechanics of their evaporation and combustion processes were studied. The need existed for visualizing the internal structure of flames including evaporation and combustion processes as well as for a better way of understanding spray particle generation mechanisms and internal structures. A particle sizer based on Fraunhofer diffraction for detecting particle size and in-line Fraunhofer holograms for observation of local spray particles were used. A novel visualizing technique based on Computer Technology was developed and is discussed.
The size distribution of a particle field hologram is obtained with a Fourier transformation of the Fraunhofer diffraction pattern of the reconstructed hologram. Off-axis absorption holograms of particle fields with known characteristics were obtained and analyzed with a commercially available instrument. The mean particle size of the reconstructed hologram was measured with an error of + or - 5 percent, while the distribution broadening was estimated within + or - 15 percent. Small sections of a pulsed laser hologram of a synthetic fuel spray were analyzed with this method thus yielding a spatially resolved size distribution. The method yields fast and accurate automated analysis of particle field holograms.
A hybrid approach to implementing the calibration equations for a multisensor hot-wire probe is discussed. The approach combines some of the speed of a look-up approach with the moderate storage requirements of direct calculation based on functional fitting. Particular attention is given to timing and storage comparisons for an X-wire probe. The method depends on the oft-employed concept of an effective cooling velocity which is a function only of the bridge output voltage.
UBV photometry is presented for 2400 stars in the OB associations of 30 Doradus in the Large Magellanic Cloud, and I discuss new spectroscopic observations of 54 stars including 24 O stars. The CCD fields cover an area of 50 square arcminutes in the central region. The entire catalog (exclusive of the dense core cluster R 136) is photometrically complete to V = B = 18 mag and U = 17 mag, although the completeness magnitudes are fainter for regions with less nebular contamination.
Calculating microwave opacity from a weakly absorbing gas mixture using a resonator requires measuring the quality factor of that resonator which necessitates accurately determining the center frequency (f(sub O)) and the half power bandwidth (Delta-f) of a noisy resonant line. The center frequency can be determined very accurately and varies very little over many measurements (a few kHz at GHz frequencies or a few hundredths of a percent). The greater source of error in estimating the Q of a resonator come from the bandwidth measurements. The half power bandwidth is determined essentially by eye-fitting a curve over a noisy resonant line and measuring with a spectrum analyzer.
For several years, discussions have been ongoing about how to analyze GPS time information in order to get the most accurate and precise time comparison between two locations. Many similar studies were done several years ago before the constellation was dominated by Block II satellites. With the Block II satellites and the use of Selective Availability (S/A), time comparisons have lost some precision and accuracy. This paper presents the results of research that was performed to find not only the best of several time comparison methods, but also to determine to what degree precision and accuracy have declined due to S/A.
Research was carried out on developing a flow field interaction model for both the dayside and nightside ionosphere of Venus. Specific topics related to the dayside ionosphere included: (1) wave particle mechanisms at the ionopause, (2) structure and dynamics of the Venus ionopause and Ionosphere, and (3) flows and fields in the Venus Ionosphere. The structure and dynamics of ion troughs was also studied in the nightside ionosphere of Venus.