JPL inputs to Lockheed study contract 950877
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The past ten years of research on computer vision have matured into a powerful real time system comprised of standardized commercial hardware, computers, and pipeline processing laboratory prototypes, supported by anextensive set of image processing algorithms. The software system was constructed to be transportable via the choice of a popular high level language (PASCAL) and a widely used computer (VAX-11/750), it comprises a whole realm of low level and high level processing software that has proven to be versatile for applications ranging from factory automation to space satellite tracking and grappling.
A detailed review of 110 of the 263 Region B/C images of the 1981 data set is undertaken and a preliminary assessment of 39 images of the 1976-79 data set is presented. The basic spatial characteristics of these images are discussed. Modeling analysis of these images after further data processing will provide useful information about Io and the planetary magnetosphere. Plans for data processing and modeling analysis are outlined. Results of very preliminary modeling activities are presented.
Deep-space exploration; information systems and space technology development; technology applications; energy and energy conversion technology; and earth observational systems and orbital applications are discussed.
The most significant accomplishments during fiscal year 1983 in a wide range of ongoing research and development tasks at the Jet Propulsion Laboratory are discussed. Deep space exploration, information systems and space technology development, technology applications, energy and energy conversion technology, and Earth observational systems are discussed.
A bibliography of internal and external documents produced by the Jet Propulsion Laboratory, based on the work performed by the Photovoltaics Program Analysis and Integration Center, is presented with annotations. As shown in the Table of Contents, the bibliography is divided into three subject areas: (1) Assessments, (2) Methdological Studies, and (3) Supporting Studies. Annotated abstracts are presented for 20 papers.
Fluidized bed reactor research techniques for fabrication of quartz linears was reviewed. Silane pyrolysis was employed in this fabrication study. Metallic contaminant levels in the silicon particles were below levels detectable by emission spectroscopy.
A summary of single event upset data for 42 device types (including RAMs, 4-bit slices, microprocessors, 4-bit counters, and flip-flops) studied at 11 different accelerator tests (performed chiefly with the Berkeley 88-inch cyclotron and the Cal Tech Van de Graaff) is presented. All bipolar and NMOS RAMs were found to be SEU sensitive, some with very low LET thresholds. Some CMOS or CMOS/SOS RAMs were hard; and the CMOS microprocessors were hard, but the bipolar and NMOS microprocessors were soft. Several devices were found to exhibit a cross section that depends strongly on LET, even when the LET is well above the LET threshold. A ranking of hardness is presented for the logic devices tested.
A data quality review for the entire set of the 1981 Region B/C images has been completed and is presented. The review indicates that almost all images are of sufficient quality to be valuable in our analysis of this data set. Five data-correlation studies for the same data set have also been completed and are useful in classifying and studying the sodium cloud morphology and its interactions with solar radiation pressure and the plasma torus. Additional progress in developing new image processing techniques and in improving the Io sodium cloud model is also discussed.
Silicon deposition on silicon seed particles by silane pyrolysis in a fluidized bed reactor (FBR) was investigated as a low cost, high throughput method to produce high purity polysilicon for solar cell applications. The emphasis of the research is fundamental understanding of fluidized bed silicon deposition. The mechanisms involved were modeled as a six-path process: heterogeneous deposition; homogeneous decomposition; coalescence; coagulation; scavenging; and chemical vapor deposition growth on fines.
Silicon material activities are described. Topics discussed include: fluidized bed technology, model predictions (reaction kinetics and grid design parameters), seed-particle cleaning procedure, runaway nucleation, thermal analysis of dendritic ribbons, and residual stress in dendritic ribbons.
The progress in the in-house program on the silane fluidized-bed system is reported. A seed-particle cleaning procedure was developed to obtain material purity near the level required to produce a semiconductor-grade product. The liner-seal design was consistently proven to withstand heating/cooling cycles in all of the experimental runs.
Local gravity accelerations and gravimetry have been determined directly from spacecraft Doppler tracking data near the Moon and various planets by the Jet Propulsion Laboratory. Researchers in many fields have an interest in planet-wide global gravimetric mapping and its applications. Many of them use their own computers in support of their studies and would benefit from being able to directly manipulate these gravity data for inclusion in their own modeling computations. Pubication of some 150 Apollo 15 subsatellite low-altitude, high-resolution, single-orbit data sets is covered. The doppler residuals with a determination of the derivative function providing line-of-sight-gravity are both listed and plotted (on microfilm), and can be ordered in computer readable forms (tape and floppy disk). The form and format of this database as well as the methods of data reduction are explained and referenced. A skeleton computer program is provided which can be modified to support re-reductions and re-formatted presentations suitable to a wide variety of research needs undertaken on mainframe or PC class microcomputers.
Pulsar arrival-time data from a timing program carried out at the Jet Propulsion Laboratory from 1968 to 1982 at 2390 MHz were analyzed to study the precision of neutron star rotation rates. Most of the 24 objects in the sample show 'timing activity' as deviations from the smooth spin-down expected from a simple electromagnetic torque mechanism. About 20 events in both frequency and frequency derivative across the sample of objects are identified, whose properties differ from those of the large-amplitude 'glitches' observed from a few objects. Prospects are good for the millisecond pulsar PSR 1937 + 214 being better than terrestrial maser clocks on time scales of a few years.
A detailed summary of the diverse encapsulation materials and techniques that evolved to meet the cost goals of the Flat-plate Solar Array (FSA) Project is presented. A typical solar cell now consists of low iron glass, two layers of ethylene vinyl acetate (EVA) polymers, a porous space, primers/adhesives, a back cover of Tedlar, and a gasket/seal for a volume cost of $1.30/sq ft. This compares well with the project goal of $1.40/sq ft.
Previously published tables of geocentric arrival times for 24 pulsars covering a 12 year span are extended here to 14.5 years. The list of pulsars is extended by nine, most of which were observed for about 4 years. Known positins of these new objects are confirmed, and limits on the proper motions are obtained. Large phase excursions in PSR 0525 + 21 are found. The orbital parameters of the binary pulsar 0820 + 02 are tentatively confirmed. Short-term timing noise in excess of that expected from receiver considerations alone is established. Variations in the timing residuals for the original 24 pulsars are analyzed for correlations with other observable parameters. Little significant correlation with changes in pulse shape or energy or with the drift correction is found on time scales of 500 pulses or longer.
The NASA All Sky Survey strategy for detecting signals of extraterrestrial origin is examined. The All Sky Survey observes the entire celestial sphere, covers a frequency range of 1-10 Ghz, and has spatial direction and frequency coverage. The survey time is dependent on the area of the sky surveyed, the telescope diameter, scan rate, the angular separation of the scans, the bandwidth of the receiver, and the frequency coverage. The distance at which a transmitter can be detected for a given sensitivity is analyzed. The interaction between scan strategy and various accumulation strategies and its effect on the sensitivity of the survey are investigated using field tests. A diagram of the SETI Sky Survey observational system is provided.
This report is a revision of the document of the same title (1986), dated August 1, which it supersedes. Model changes during 1986 and 1987 included corrections for antenna feed rotation, refraction in modelling antenna axis offsets, and an option to employ improved values of the semiannual and annual nutation amplitudes. Partial derivatives of the observables with respect to an additional parameter (surface temperature) are now available. New versions of two figures representing the geometric delay are incorporated. The expressions for the partial derivatives with respect to the nutation parameters have been corrected to include contributions from the dependence of UTI on nutation. The authors hope to publish revisions of this document in the future, as modeling improvements warrant.