Apollo optical subsystem and LM alignment optical telescope. Volume 1 - Program summary Final report
Hardware description of optical equipment developed for Apollo program
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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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Optical-to-optical interface device
Studies were conducted on the performance of a photoactivated dc liquid crystal light valve. The dc light valve is a thin film device that consists of two transparent electrodes, deposited on glass substrates, that enclose a thin film photoconductor (cadmium sulfide) and a thin layer of a nematic liquid crystal that operates in the dynamic scattering mode. The work was directed toward application of the light valve to high resolution non-coherent light to coherent light image conversion. The goal of these studies was to improve the performance and quality of the already existing dc light valve device and to evaluate quantitatively the properties and performance of the device as they relate to the coherent optical data processing application. As a result of these efforts, device sensitivity was improved by a factor of ten, device resolution was improved by a factor of three, device lifetime was improved by two-orders of magnitude, undesirable secondary liquid crystal scattering effects were eliminated, the scattering characteristics of the liquid crystal were thoroughly documented, the cosmetic quality of the devices was dramatically improved, and the performance of the device was fully documented.
Jacobson, A. D.↗
Process for producing a well-adhered durable optical coating on an optical plastic substrate
A low temperature plasma polymerization process is described for applying an optical plastic substrate, such as a polymethyl methacrylate lens, with a single layer abrasive resistant coating to improve the durability of the plastic.
Kubacki, R. M.↗
Development of an optical parallel logic device and a half-adder circuit for digital optical processing
The paper describes the fabrication and operation of an optical parallel logic (OPAL) device which performs Boolean algebraic operations on binary images. Several logic operations on two input binary images were demonstrated using an 8 x 8 device with a CdS photoconductor and a twisted nematic liquid crystal. Two such OPAL devices can be interconnected to form a half-adder circuit which is one of the essential components of a CPU in a digital signal processor.
Athale, R. A.↗
Energy normalization of TV viewed optical correlation (automated correlation plane analyzer for an optical processor)
An automatic correlation plane processor that can rapidly acquire, identify, and locate the autocorrelation outputs of a bank of multiple optical matched filters is described. The read-only memory (ROM) stored digital silhouette of each image associated with each matched filter allows TV video to be used to collect image energy to provide accurate normalization of autocorrelations. The resulting normalized autocorrelations are independent of the illumination of the matched input. Deviation from unity of a normalized correlation can be used as a confidence measure of correct image identification. Analog preprocessing circuits permit digital conversion and random access memory (RAM) storage of those video signals with the correct amplitude, pulse width, rising slope, and falling slope. TV synchronized addressing of 3 RAMs permits on-line storage of: (1) the maximum unnormalized amplitude, (2) the image x location, and (3) the image y location of the output of each of up to 99 matched filters. A fourth RAM stores all normalized correlations. A normalization approach, normalization for cross correlations, a system's description with block diagrams, and system's applications are discussed.
Grumet, A.↗
Radio occultation of Jupiter's ring - Bounds on optical depth and particle size and a comparison with infrared and optical results
A comparison of Voyager 1 data of the Jovian ring at radio, infrared and optical wavelengths suggests a population density that either falls more rapidly than the inverse square of the linear size, or is sharply bounded in maximum particle size. A fragmentation power law is used to estimate a minimum particle radius of 1-2 microns, and a specific model is developed which consists of a power law distribution of lossless or slightly absorbent Mie scatterers with a refractive index near 1.62, a power law index of -3.5, and a minimum particle size of 1.5 microns. The maximum particle radius is not critical, provided that it is greater than 4 microns, and the power law polydispersion of lossless or low absorbent Mie scatterers is consistent with previously reported observations as long as the parameter size minimum is 20 and the power index is about -3.5.
Tyler, G. L.↗
X-ray and optical profiler analysis of electroformed X-ray optics
Electroformed grazing incidence mirrors were tested with X-rays and were measured with an optical profiler. Their total effective areas are greater than about 70 percent of the theoretical values both for 1.5- and 6.4-keV X-rays. The half-power diameters are less than about 2 min of arc at 1.5 keV. A design of the mirror array telescope for high energies which has a total effective area of about 1000 sq cm for 7-keV X-rays is presented.
Matsui, Yutaka↗
A catalog of small, optically selected molecular clouds - Optical, infrared, and millimeter properties
A catalog of small, optically selected molecular clouds is presented. The relevant selection criteria were small angular size, large central opacity, and freedom from connecting opaque material. The mean ellipticity of the clouds in the catalog is 2.0, with a maximum ellipticity of 7. The position angle of the clouds is uncorrelated with the direction of the Galactic plane. About 60 percent of the cataloged clouds have associated IRAS Point Source Catalog (PSC) sources in their cores or envelopes. The likelihood of a detection of a PSC source is some 6.1 times higher for the core regions of the clouds than for the envelopes, indicating a strong association of FIR sources and Bok globules. Of a sample of 97 of the clouds observed in the J = 2-1 line of (C-12)O, 70 percent have cold gas kinetic temperatures and approximately sonic line widths. The remaining 30 percent are about equally divided between those clouds likely to be radiatively heated by nearby stars and those undergoing active protostellar collapse or outflows with no bulk gas heating.
Clemens, Dan P.↗
Comparison of satellite-inferred (SAGE II) aerosol optical depths with corresponding airborne sunphotometer optical depths
Solar radiation measurements were made with an airborne multiwavelength autotracking sunphotometer detector off the northeastern coast of Brazil on April 6, 1985. These measurements are used to validate solar radiation measurements from the Stratospheric Aerosol and Gas Experiment (SAGE II). The SAGE II data below 17.5 km are dominated by attenuation due to thunderstorm-generated cirrus clouds. When integrated above 17.5 km, however, the aerosol extinction profiles from SAGE II yield aerosol optical depths that are consistent with the corresponding sunphotometer values above 10.1 km.
Livingston, John M.↗
Optical transmission through a polarization preserving single mode optical fiber at two Ar(+) laser wavelengths
The transmission characteristics of two Ar(+) laser wavelengths through a twenty meter Panda type Polarization Preserving Single Mode Optical Fiber (PPSMOF) were measured. The measurements were done with both single and multi-longitudinal mode radiation. In the single longitudinal mode case, a degrading Stimulated Brillouin Scattering (SBS) is observed as a backward scattering loss. By choosing an optimum coupling system and manipulating the input polarization, the threshold of the SBS onset can be raised and the transmission efficiency can be increased.
Tedjojuwono, Ken K.↗
Optical Phase-Locked Loop For Optical Communication
Experimental apparatus includes two diode-pumped solid-state lasers of non-planar-ring-oscillator type, one represents the transmitting oscillator, other local oscillator in receiver. Output of transmitting oscillator is amplitude-modulated with pulse-position-modulated data stream. Phase-error variance of less than 0.05 mrad(Sup 2) achieved with relatively-narrow-band loop. Applications include free-space and fiber-optic communications, navigation, and scientific instrumentation in which receivers are required to track phases of transmitted signals.
Win, Moe Z.↗
Test methods for optical disk media characteristics (for 356 mm ruggedized magneto-optic media)
Standard test methods for computer storage media characteristics are essential and allow for conformance to media interchange standards. The test methods were developed for 356 mm two-sided laminated glass substrate with a magneto-optic active layer media technology. These test methods may be used for testing other media types, but in each case their applicability must be evaluated. Test methods are included for a series of different media characteristics, including operational, nonoperational, and storage environments; mechanical and physical characteristics; and substrate, recording layer, and preformat characteristics. Tests for environmental qualification and media lifetimes are also included. The best methods include testing conditions, testing procedures, a description of the testing setup, and the required calibration procedures.
Podio, Fernando L.↗
Multifrequency observations of the optically active radio-quiet quasar GQ Comae. II - Ultraviolet, optical, and infrared continuum variability
This paper summarizes the data and preliminary results of a 3 yr long project to monitor the continuum variability of GQ Comae (PG 1202 + 281) from 0.12 micron to 3.5 microns. Substantial variability in the optical/UV flux was observed. The variability is examined using a geometrically thin accretion disk model. The model is able to reproduce the variations, but contains problems with physical consistency. A comparison of the optical/UV data and the IR data indicates that the flux at 2.2 microns did not respond to the optical-UV continuum increase until nearly 250 days after the outburst and suggests that the variable flux at this wavelength is due to heated dust. We model the IR emission with a dust component which is heated by the radiation from the accretion disk. We show that a simple model using a disklike distribution of heated dust grains can explain most of the IR variability in a natural way.
Sitko, Michael L.↗
Optical Rain Gauge Performance: Second Workshop on Optical Rain Gauge Measurements
The primary focus of the workshop was on the performance and reliability of STi mini-Optical Rain Gauges in a number of environments, including deployments on ships and buoys in the western equatorial Pacific Ocean during the TOGA/COARE field experiment, deployments on buoys in U.S. coastal waters, and comparisons with other types of rain gauges on the Virginia coast and in Florida. The workshop was attended by 20 investigators, representing 10 different institutions, who gathered to present new results obtained since the first workshop (April 1993), to discuss problems, to consider solutions, and to chart future directions. Post-TOGA/COARE calibration studies were also presented.
Short, David A.↗
Fiber Optic Control System integration for advanced aircraft. Electro-optic and sensor fabrication, integration, and environmental testing for flight control systems: Laboratory test results
This report presents the data obtained in laboratory testing of the optical sensors and multiplexing architecture developed for flight testing in the NASA F-18 systems research aircraft.
Kessler, Bradley L.↗
Optically-Switched Resonant Tunneling Diodes for Space-Based Optical Communication Applications
We are developing a new type of digital photo-receiver that has the potential to perform high speed optical-to-electronic conversion with a factor of 10 reduction in component count and power dissipation. In this paper, we describe the room-temperature photo-induced switching of this InP-based device which consists of an InGaAs/AlAs resonant tunneling diode integrated with an InGaAs absorber layer. When illuminated at an irradiance of greater than 5 Wcm(exp -2) using 1.3 micromillimeter radiation, the resonant tunneling diode switches from a high-conductance to a low-conductance electrical state and exhibits a voltage swing of up to 800 mV.
Moise, T. S.↗
Remote-Sensing Reflectance and Inherent Optical Properties for Optically Deep Waters: A Revisit
Remote-sensing reflectance (r(rs)) is defined as the ratio of upwelling radiance to downwelling irradiance. Relationships between remote-sensing reflectance and inherent optical properties serve as the basis for ocean-color modeling, as well as for spectral deduction of oceanic constituents through analytical/semi-analytical models of ocean color. A decade ago, a simple and concise formula based on Monte Carlo simulations was developed by relating rrs to a property u, the ratio of backscattering (b(b)) to the sum of absorption (a) and backscattering (u = b(b)/(a+b(b))). This relationship generally ignored the shape differences in phase functions between molecular scattering and particle scattering. In this study, the relationship is updated with separate parameters for molecular and particle scattering, based on the Radiative Transfer Equation through use of Hydrolight numerical solutions. The new approach fits r(rs) better than an earlier traditional formula, for both clear and turbid waters.
Lee, Zhong-Ping↗
Ultra-Fast All-Optical Logic Gates for the Optical Computing
We demonstrated a picosecond Exclusive OR and a nanosecond AND gates. An inverter gate has been designed. Their combination forms the rest of other gates to build an all- optical computing system.
Abdeldayem, Hossin↗