ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Inorganic Chemistry  (7,125)
  • Industrial Chemistry  (1,701)
  • INSTRUMENTATION AND PHOTOGRAPHY  (1,195)
  • 1975-1979  (5,349)
  • 1950-1954  (2,937)
  • 1915-1919  (1,735)
Collection
Keywords
Publisher
Years
Year
  • 1
    facet.materialart.
    Unknown
    The Surface Contour Radar, a unique remote sensing instrument (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A 36 GHz computer controlled airborne Surface Contour Radar (SCR) is described, which was developed by the Naval Research Laboratory and NASA. The system uses pulse-compression techniques and dual frequency carriers spaced far enough apart to be decorrelated on the sea surface. The continuous wave transmitter is biphase modulated, the return signal is autocorrelated, and the code length and clock rate are variable, providing selectable range resolutions of 0.15, 0.30, 0.61 and 1.52 m. The SCR generates a false-color coded elevation map of the sea surface below the aircraft in real time, and can routinely produce ocean directional wave spectra with off-line data processing.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Detection of hairline cracks in textured silicon solar cells (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Using a focused laser scanner, the optical technique described in the present paper can be used to detect hairline cracks of the type occurring in solar cells subjected to surface texturing. The technique is capable of detecting cracks of the order of a few microns, which, otherwise, can be observed only under high magnification using an optical microscope. The technique consists of scanning a solar cell with a finely focused laser beam and recording the photoresponse (short circuit current or open circuit voltage) as a function of beam position. The presence of a crack is manifested by a sharp dip in the photoresponse.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Mar. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    The low-noise 115-GHz receiver on the Columbia-GISS 4-ft radio telescope (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The superheterodyne millimeter-wave radiometer on the Columbia-GISS 4-ft telescope is described. This receiver uses a room-temperature Schottky diode mixer, with a resonant-ring filter as LO diplexer. The diplexer has low signal loss, efficient LO power coupling, and suppresses most of the LO noise at both sidebands. The receiver IF section has a parametric amplifier as its first stage with sufficient gain to overcome the second-stage amplifier noise. A broad-banded quarter-wave impedance transformer minimizes the mismatch between mixer and paramp. At 115 GHz, the SSB receiver noise temperature is 860 K, which is believed to be the lowest figure so far reported for a room-temperature receiver at this frequency.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Transactions on Microwave Theory and Techniques; MTT-27; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Geodetic interferometry submission for the IUGG Quadrennial Report (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The present paper reviews the activities of two major VLBI (Very Long Baseline Interferometry) groups, within the United States, which have been concentrating on geodetic measurements for a number of years. The activities have resulted in the development of transportable VLBI terminals for regional surveying applications; development of VLBI techniques for obtaining station positions; establishment of relative epochs and rates of the hydrogen maser clocks at the stations; the acquisition of polar motion and earth rotation data in support of deep space tracking functions; and the development of VLBI techniques necessary for tectonic measurements on trans- and intercontinental baselines and for astrometry, polar-motion and earth-rotation observations.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Qualitative and quantitative flow visualization technique using ozone (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The paper describes a new flow-visualization technique based on the absorption of ultraviolet light by ozone. Ozone is an excellent tracer, because as a gas it has the same effective physical properties as air. Ozone strongly absorbs the principal line (253.7 nm) of a mercury lamp, so that when an ozone-traced flow passes between a mercury lamp and a fluorescent screen, a sharp, shadow-like image of the ozone tracer is cast on the screen. Quantitative photometry can be carried out by replacing the screen with ultraviolet detectors that yield the path-integrated column density of ozone in the flow. High-speed quantitative point monitoring (10 Hz at 10 ppb O3) is possible with capillary probes and chemiluminescent analysis.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; June 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    A high resolution holographic particle sizing system (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: This paper will review briefly the requirements of holography with respect to particle sizing techniques. A holographic construction system and the appropriate reconstruction system will be discussed regarding their characteristics and performance (i.e. system resolution, magnification, system aberration and correction of aberrations, and maximum total test volume). The capabilities of a commercial particle sizing system used to obtain particle sizes and distribution information from reconstructed holograms will be described and characterized. It will be shown that by using the methods described, high resolution throughout large test volumes can be achieved.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Optical Engineering; 18; May-June
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Measurement of the polarization effects of an instrument using partially polarized light (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Accuracy of a radiometer is adversely affected by scene polarization if the receiving optical system is sensitive to polarization. It is therefore necessary to specify and measure the sensitivity of the system to polarized light. The Mueller-Stokes matrix of an instrument may be determined experimentally and used to predict the effects of the instrument on any beam. The specification of a maximum polarization sensitivity stated in terms of the degree of polarization produced in an unpolarized beam can be experimentally verified even though an unpolarized beam is not available in the laboratory for direct measurement.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Mar. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Airborne laser induced fluorescence system for measuring OH and other trace gases in the parts-per-quadrillion to parts-per-trillion range (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Described in detail is a laser induced fluorescence system which has been successfully interfaced with two aircraft sampling platforms (i.e., Sabreliner jet and an L-188C Electra). This system, which has been under development for four years, presently consists of the following major components: (1) a Nd-Yag laser driven oscillator-amplifier dye laser; (2) a sampling manifold with associated fluorescence detection optics; (3) an OH calibration chamber; (4) a laser beam steering assembly; and (5) sampling electronics and data processing hardware. During the last three years, this system has been flown some 50,000 air miles making tropospheric OH radical measurements over the latitude range of 70 N to 57 S. OH concentrations measured during these flights have ranged from 30 parts-per-quadrillion (3.7 x 10 to the 5th molecules/sq cm) at altitudes of 6 km to 0.8 parts-per-trillion (2.0 x 10 to the 7th molecules/sq cm) at 0.5 km. Computations have been completed which indicate that the existing aircraft system with modest modifications should also be capable of detecting natural tropospheric levels of NO, SO2, CH2O, NO2, HNO2, NO3, H2O2 and CS2 by using both conventional laser-induced fluorescence methodology and multiphoton techniques.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Computer image processing and recognition (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A systematic introduction to the concepts and techniques of computer image processing and recognition is presented. Consideration is given to such topics as image formation and perception; computer representation of images; image enhancement and restoration; reconstruction from projections; digital television, encoding, and data compression; scene understanding; scene matching and recognition; and processing techniques for linear systems.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Modification of a Kowa RC-2 fundus camera for self-photography without the use of mydriatics (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Research on retinal circulation during space flight required the development of a simple technique to provide self monitoring of blood vessel changes in the fundus without the use of mydriatics. A Kowa RC-2 fundus camera was modified for self-photography by the use of a bite plate for positioning and cross hairs for focusing the subject's retina relative to the film plane. Dilation of the pupils without the use of mydriatics was accomplished by dark-adaption of the subject. Pictures were obtained without pupil constriction by the use of a high speed strobe light. This method also has applications for clinical medicine.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Brain Research Bulletin; 4; 1979
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 11
    facet.materialart.
    Unknown
    On-axis velocity component measurement with laser velocimeters (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The application of Doppler shifted laser light to the measurement of the two velocity components normal to the optical axis of the system is relatively simple as compared to the measurement of the on-axis velocity component. The present paper deals with the reference-beam (local oscillator) technique and the dual-beam (fringe mode) technique, which have been developed for measuring the on-axis component. Some results obtained for the on-axis component are examined.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: AIAA Journal; 17; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 12
    facet.materialart.
    Unknown
    Remote measurement of the transverse wind velocity component using a laser Doppler velocimeter (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The wind speed transverse to the line-of-sight of a laser Doppler radar has been measured using the intensity fluctuations of the returned signal. These measurements were made at a range of 100 m with a CO2 CW laser Doppler velocimeter, which was simultaneously performing its design function of determining the radial velocity component. The transverse component measurements are compared with those obtained using a u, v, w Gill propeller anemometer.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Sept. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 13
    facet.materialart.
    Unknown
    Field-widened pinhole camera (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Wood demonstrated a method in 1906 that allowed 180-deg FOV but required that the film be immersed in a tank of water. This paper presents a technique that yields the same 180-deg FOV without the necessity of wetting the film. Rays from a 180-deg FOV cone are reduced to 84-deg cone due to refraction at the glass surface. If the cone were then incident on another glass/air plane surface, it would be expanded back to 180 deg.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Sept. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 14
    facet.materialart.
    Unknown
    Magnetic shielding in a low temperature torsion pendulum experiment (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A new type of ether drift experiment searches for anomalous torques on a permanent magnet. A torsion pendulum is used at liquid helium temperature, so that superconducting cylinders can be used to shield magnetic fields. Lead shields attenuate the earth's field, while Nb-Sn shields fastened to the pendulum contain the fields of the magnet. The paper describes the technique by which the earth's field can be reduced below 0.0001 G while simultaneously the moment of the magnet can be reduced by a factor 7 x 10 to the 4th.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 15
    facet.materialart.
    Unknown
    Measurement of turbulent fluctuations in high-speed flows using hot wires and hot films (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The paper examines the dynamic calibrations of the hot film and modified hot-wire probes with a view to assess their suitability for use in experiments for the measurement of turbulent fluctuations in compressible boundary-layer flows. Results are presented of tests on some sensors in both subsonic and supersonic boundary-layer flows. A simple technique is presented for determining dynamic calibration correction factors for the sensitivities involved.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 16
    facet.materialart.
    Unknown
    Polarization-sensitive spectroradiometer - Two methods for overcoming the problems of measuring reflectance spectra (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The spectra obtained using a spectroradiometer are incorrect if the incident light from the sample is polarized, and if, at the same time, polarization is introduced into the transmitted beam by components of the spectroradiometer. Two methods are proposed for obtaining correct power reflectance spectra. One way is to average two incorrect reflectance spectra, which are taken at mutually orthogonal angles of rotation of the radiometer about its optical axis. Another way is by averaging reflectance spectra of mutually orthogonal polarized light components. When the orientation of one component is chosen such that it is in the plane of polarization of the incoming light, the latter method also gives the correct degree of polarization.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Feb. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 17
    facet.materialart.
    Unknown
    Remote sensing using solid-state array technology (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The paper describes the design features and capabilities of a remote sensor that uses solid-state linear arrays and operates in a 'pushbroom' scan mode to provide the required performance. Pushbroom scanning is a term describing the technique of using the forward motion of a satellite platform to sweep a linear array of detectors oriented perpendicular to the ground track across a scene being imaged. One array is typically used for each spectral channel. Satellite motion provides one direction of scan and electronic sampling of the detectors in the crosstrack dimension provides the orthogonal scan component to form an image. The detector array is sampled at the appropriate rate so that contiguous lines are produced. The performance of a pushbroom system is discussed relative to radiometric sensitivity, detector array geometric fidelity, and radiometric correction. System advantages are precision geometric positioning of the detectors, very high sensitivity and favorable SNR, low power consumption, and no moving optics.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 18
    facet.materialart.
    Unknown
    Ray-tracing the convex curved crystal X-ray spectrograph (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The convex curved crystal X-ray spectrograph has recently seen increasing use for the spectral analysis of transient plasmas. The present paper describes the calculation of ray paths through the spectrograph for both localized and extended sources. The method traces a ray from any given source point to its point of diffraction by the curved crystal and then to the imaging circle, where the image point is obtained. Application of the ray tracing method is made to some actual experimental configurations to obtain resolution values and source sizes. Wavelength calibrations are obtainable with the ray tracing method in advance of instrument construction.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Feb. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 19
    facet.materialart.
    Unknown
    Graphic design of pinhole cameras (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The paper describes a graphic technique for the analysis and optimization of pinhole size and focal length. The technique is based on the use of the transfer function of optical elements described by Scott (1959) to construct the transfer function of a circular pinhole camera. This transfer function is the response of a component or system to a pattern of lines having a sinusoidally varying radiance at varying spatial frequencies. Some specific examples of graphic design are presented.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Feb. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 20
    facet.materialart.
    Unknown
    Development of a portable, high-energy radiographic source (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A two-year program has been undertaken to develop a portable high-energy (3-4 MeV) radiographic system for in-service and repair inspections of components at nuclear power stations. The basic design concept uses a lightweight portable linear accelerator. This paper describes the design objectives, concepts employed, and progress to date. Specific potential applications and accompanying radiographic techniques are discussed, along with novel beam-angulation devices that permit utilization in areas of highly restricted access.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 21
    facet.materialart.
    Unknown
    Broadband electrostatic acoustic transducer for ultrasonic measurements in liquids (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A broadband capacitive electrostatic acoustic transducer (ESAT) has been developed for use in a liquid environment at megahertz frequencies. The ESAT basically consists of a thin conductive membrane stretched over a metallic housing. The membrane functions as the ground plate of a parallel plate capacitor, the other plate being a dc biased electrode recessed approximately 10 microns from the electrically grounded membrane. An ultrasonic wave incident on the membrane varies the membrane-electrode gap spacing and generates an electrical signal proportional to the wave amplitude. The entire assembly is sealed for immersion in a liquid environment. Calibration of the ESAT with incident ultrasonic waves of constant displacement amplitude from 1 to 15 MHz reveals a decrease in signal response with increasing frequency independent of membrane tension. The use of the ESAT as a broadband ultrasonic transducer in liquids with a predictable frequency response is promising.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; Jan. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 22
    facet.materialart.
    Unknown
    Adjacency effects on imaging by surface reflection and atmospheric scattering - Cross radiance to zenith (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The paper discusses an analytical solution for the nadir radiance as measured from a satellite, based on a simplified single-scattering approximation in which the scattered radiation is not subject to extinction. In the solution, terms can be identified as due to a reflection from the vicinity of the object pixel, and respectively, (1) upward scattering to zenith above the object pixel (cross radiance), and (2) downward scattering from the entire atmosphere to the object pixel (cross irradiance). It is shown that the cross radiance is proportional to the forward scattering optical thickness, as defined, and the cross irradiance to the backscattering optical thickness. In addition, explicit expressions and computer solutions for the cross radiance from annular or from rectangular reflecting areas are presented. It is concluded that the effect depends on the height distribution and on the sharpness of the forward peak of the scattering particles.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Aug. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 23
    facet.materialart.
    Unknown
    Microwave sensing from orbit (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Microwave sensors, used in conjunction with the traditional sensors of visible and infrared light to extend present capabilities of global weather forecasts and local storm watches, are discussed. The great advantage of these sensors is that they can penetrate or 'see' through cloud formations to monitor temperature, humidity and wind fields below the clouds. Other uses are that they can penetrate the earth deeper than optical and IR systems; they can control their own angle of incidence; they can detect oil spills; and they can enhance the studies of the upper atmosphere through measurement of temperature, water vapor and other gaseous species. Two types of microwave sensors, active and passive, are examined. Special attention is given to the study of the microwave radiometer and the corresponding temperature resolution as detected by the antenna. It is determined that not only will the microwave remote sensors save lives by allowing close monitoring of developing storms, but also save approximately $172 million/year.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Spectrum; 16; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 24
    facet.materialart.
    Unknown
    Automated electrical impedance technique for rapid enumeration of fecal coliforms in effluents from sewage treatment plants (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Aplied and Environmental Microbiology; 37; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 25
    facet.materialart.
    Unknown
    Rapid, single-step most-probable-number method for enumerating fecal coliforms in effluents from sewage treatment plants (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A single-step most-probable-number method for determining the number of fecal coliform bacteria present in sewage treatment plant effluents is discussed. A single growth medium based on that of Reasoner et al. (1976) and consisting of 5.0 gr. proteose peptone, 3.0 gr. yeast extract, 10.0 gr. lactose, 7.5 gr. NaCl, 0.2 gr. sodium lauryl sulfate, and 0.1 gr. sodium desoxycholate per liter is used. The pH is adjusted to 6.5, and samples are incubated at 44.5 deg C. Bacterial growth is detected either by measuring the increase with time in the electrical impedance ratio between the innoculated sample vial and an uninnoculated reference vial or by visual examination for turbidity. Results obtained by the single-step method for chlorinated and unchlorinated effluent samples are in excellent agreement with those obtained by the standard method. It is suggested that in automated treatment plants impedance ratio data could be automatically matched by computer programs with the appropriate dilution factors and most probable number tables already in the computer memory, with the corresponding result displayed as fecal coliforms per 100 ml of effluent.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied and Environmental Microbiology; 37; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 26
    facet.materialart.
    Unknown
    Tomographical imaging using uniformly redundant arrays (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: An investigation is conducted of the behavior of two types of uniformly redundant array (URA) when used for close-up imaging. One URA pattern is a quadratic residue array whose characteristics for imaging planar sources have been simulated by Fenimore and Cannon (1978), while the second is based on m sequences that have been simulated by Gunson and Polychronopulos (1976) and by MacWilliams and Sloan (1976). Close-up imaging is necessary in order to obtain depth information for tomographical purposes. The properties of the two URA patterns are compared with a random array of equal open area. The goal considered in the investigation is to determine if a URA pattern exists which has the desirable defocus properties of the random array while maintaining artifact-free image properties for in-focus objects.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Apr. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 27
    facet.materialart.
    Unknown
    Nuclear Science Symposium, 25th, and Symposium on Nuclear Power Systems, 10th, Washington, D.C., October 18-20, 1978, Proceedings (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Detectors of various types are discussed, taking into account drift chambers, calorimetry, multiwire proportional chambers, signal processing, the use of semiconductors, and photo/optical applications. Circuits are considered along with instrumentation for space, nuclear medicine instrumentation, data acquisition and systems, environmental instrumentation, reactor instrumentation, and nuclear power systems. Attention is given to a new approach to high accuracy gaseous detectors, the current status of electron mobility and free-ion yield in high mobility liquids, a digital drift chamber digitizer system, the stability of oxides in high purity germanium, the quadrant photomultiplier, and the theory of imaging with a very limited number of projections.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 28
    facet.materialart.
    Unknown
    On the foci of Tandem Wadsworth spectrographs (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The horizontal foci of a Tandem Wadsworth spectrograph are calculated by using the correct ruling densities for both gratings. Results are quite different from those of previous analyses that used approximate ruling densities. Ray tracings confirm the analyses with the correct ruling densities and also indicate that this spectrograph possesses the excellent, nearly stigmatic properties found by the approximate analyses.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Optical Society of America; vol. 69
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 29
    facet.materialart.
    Unknown
    DSN water vapor radiometer: Tropospheric range delay calibration (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A discussion is presented of the Deep Space Network water vapor radiometer by means of simultaneous antenna temperature and radiosonde measurements at Edwards Air Force Base. The calibration of radiometer gain and hot load radiometric noise temperature is also described. Calibration equations are given. It is found that with a selected data set, the RMS error is less than 1 cm over a total delay range of 9 to 38 cm. Limitations on the use of the water vapor radiometer are also given.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: The Deep Space Network; p 136-145
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 30
    facet.materialart.
    Unknown
    Further developments in simple total energy sensors (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A simple total energy probe concept using principles of laminar flow around a cylinder and pressure distribution is reviewed and flow fields around cylinders normal to and inclined to the flow are described. A variety of bent-up probe configurations were tested to explore variations in geometry. Test results are presented on the effects of sensor length, hole location, and angle of sweep. Comparisons are made with other probe tests reported in the literature. Damping restrictors and their use in filtering gusts are summarized. Flow field effects, indicating the variables involved for different mounting locations on aircraft, are discussed.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 219-246
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 31
    facet.materialart.
    Unknown
    Monitor proportional counter (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: An Uhuru class Ar-CO2 gas filled proportional counter sealed with a 1.5 mil beryllium window and sensitive to X-rays in the energy bandwidth from 1.5 to 22 keV is presented. This device is coaligned with the X-ray telescope aboard the Einstein Observatory and takes data as a normal part of the Observatory operations.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: HEAO Sci. Symp.; p 347-366
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 32
    facet.materialart.
    Unknown
    AVHRR/1-FM Advanced Very High Resolution Radiometer (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The advanced very high resolution radiometer is discussed. The program covers design, construction, and test of a breadboard model, engineering model, protoflight model, mechanical/structural model, and a life test model. Special bench test and calibration equipment was developed for use on the program. The flight model program objectives were to fabricate, assemble and test four of the advanced very high resolution radiometers along with a bench cooler and collimator.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-160059
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 33
    facet.materialart.
    Unknown
    Self-synchronizing Schlieren photography and interferometry for the visualization of unsteady transonic flows (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The use of self synchronizing stroboscopic Schlieren and laser interferometer systems to obtain quantitative space time measurements of distinguished flow surfaces, steakline patterns, and the density field of two dimensional flows that exhibit a periodic content was investigated. A large field single path stroboscopic Schlieren system was designed, constructed and successfully applied to visualize four periodic flows: near wake behind an oscillating airfoil; edge tone sound generation; 2-D planar wall jet; and axisymmetric pulsed sonic jet. This visualization technique provides an effective means of studying quasi-periodic flows in real time. The image on the viewing screen is a spatial signal average of the coherent periodic motion rather than a single realization, the high speed motion of a quasi-periodic flow can be reconstructed by recording photographs of the flow at different fixed time delays in one cycle. The preliminary design and construction of a self synchronizing stroboscopic laser interferometer with a modified Mach-Zehnder optical system is also reported.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-164839
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 34
    facet.materialart.
    Unknown
    A gas chromatographic air analyzer fabricated on a silicon wafer (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A miniature gas analysis system has been built based on the principles of gas chromatography (GC). The major components are fabricated in silicon using photolithography and chemical etching techniques, which allows size reductions of nearly three orders of magnitude compared to conventional laboratory instruments. The chromatography system consists of a sample injection valve and a 1.5-m-long separating capillary column, which are fabricated on a substrate silicon wafer. The output thermal conductivity detector is separately batch fabricated and integrably mounted on the substrate wafer. The theory of gas chromatography has been used to optimize the performance of the sensor so that separations of gaseous hydrocarbon mixtures are performed in less than 10 s. The system is expected to find application in the areas of portable ambient air quality monitors, implanted biological experiments, and planetary probes.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Transactions on Electron Devices; ED-26; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 35
    facet.materialart.
    Unknown
    A real-time electronic imaging system for solar X-ray observations from sounding rockets (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A real-time imaging system for displaying the solar coronal soft X-ray emission, focussed by a grazing incidence telescope, is described. The design parameters of the system, which is to be used primarily as part of a real-time control system for a sounding rocket experiment, are identified. Their achievement with a system consisting of a microchannel plate, for the conversion of X-rays into visible light, and a slow-scan vidicon, for recording and transmission of the integrated images, is described in detail. The system has a quantum efficiency better than 8 deg above 8 A, a dynamic range of 1000 coupled with a sensitivity to single photoelectrons, and provides a spatial resolution of 15 arc seconds over a field of view of 40 x 40 square arc minutes. The incident radiation is filtered to eliminate wavelengths longer than 100 A. Each image contains 3.93 x 10 to the 5th bits of information and is transmitted to the ground where it is processed by a mini-computer and displayed in real-time on a standard TV monitor.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Space Science Instrumentation; 5; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 36
    facet.materialart.
    Unknown
    Portable high-resolution laser monochromator-interferometer with multichannel electronic readout (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A high-resolution 0.4-m monochromator is described for use in wavelength diagnosis of tunable pulsed and CW laser sources in the 3000-10,000-A region. The f/20 design uses an echelle grating in an over-and-under Ebert configuration with a scanned photodiode array to provide a real-time multichannel display of spectral output. Absolute wavelength may be determined to 0.1 A with the monochromator, and a Fabry-Perot interferometer attachment extends linewidth measurement capability to 0.01 A or better. Spectra are displayed on a storage oscilloscope, and calculation of laser parameters is explained. The instrument measures 70 cm long x 15 cm wide x 20 cm high.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Dec. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 37
    facet.materialart.
    Unknown
    Further laboratory studies and stratospheric flight of a mass spectrometer beam system (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A gas expansion system combined with a mass spectrometer has been tested and flown successfully in the stratosphere. Through a sequence of orifices and high speed pumping, gas particles were formed into a molecular beam and analyzed by a sensitive mass spectrometer. During two balloon flights, vertical profiles of all major atmospheric constituents as well as O3, CO2, H2O and others were obtained. Gases such as AR38 and O16;O17 provided in-flight calibration standards. The sensitivity of the system was such that gases with mixing ratios of 10 ppb at an ambient pressure of about 10 mbar were detectable.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 38
    facet.materialart.
    Unknown
    Infrared radiometer for the Pioneer Venus orbiter. I - Instrument description (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A ten-channel IR radiometer for the Pioneer Venus orbiter is described. The experimental techniques used and the design of the instrumentation by which they were implemented are considered. Emphasis is placed on temperature sounding, limb sounding, limb darkening, zenith scanning, cloud top temperature, spectral albedo and water vapor measurements. Instrumentation description is also given including optics, detectors, and electronics. Attention is given to data acquisition and handling, calibration, and in-flight performance.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Dec. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 39
    facet.materialart.
    Unknown
    Application of satellite time transfer in autonomous spacecraft clocks (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The conceptual design of a spacecraft clock that will provide a standard time scale for experimenters in future spacecraft., and can be sychronized to a time scale without the need for additional calibration and validation is described. The time distribution to the users is handled through onboard computers, without human intervention for extended periods. A group parallel binary code, under consideration for onboard use, is discussed. Each group in the code can easily be truncated. The autonomously operated clock not only achieves simpler procedures and shorter lead times for data processing, but also contributes to spacecraft autonomy for onboard navigation and data packetization. The clock can be used to control the sensor in a spacecraft, compare another time signal such as that from the global positioning system, and, if the cost is not a consideration, can be used on the ground in remote sites for timekeeping and control.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-80572
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 40
    facet.materialart.
    Unknown
    Toxic level hypergolic vapor detection sensor development (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Development of an electrochemical sensor technology capable of PPB level hypergolic vapor sensing is reported. A portable instrument capable of meeting the design goals is described.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-154633 , KSC-TR-28-1
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 41
    facet.materialart.
    Unknown
    Frequency-scanning particle size spectrometer (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A particle size spectrometer having a fixed field of view within the forward light scattering cone at an angle theta sub s between approximately 100 and 200 minutes of arc (preferably at 150 minutes), a spectral range extending approximately from 0.2 to 4.0 inverse micrometers, and a spectral resolution between about 0.1 and 0.2 inverse micrometers (preferably toward the lower end of this range of spectral resolution), is employed to determine the distribution of particle sizes, independently of the chemical composition of the particles, from measurements of incident light, at each frequency, sigma (=1/lambda), and scattered light, I(sigma).
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 42
    facet.materialart.
    Unknown
    Distributed-switch Dicke radiometers (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A radiometer on an orbiting spacecraft is described which derives high spatial resolution information from terrestrial and atmospheric regions. The N elements or subapertures on the spacecraft transduce electromagnetic energy into electric signals. Many or all of the elements are simultaneously illuminated by electromagnetic energy radiated from the same region. Identical, parallel processing channels are responsive to the N elements. Each of the channels includes a variable gain amplifier responsive to the signal transduced by its corresponding array elements. The gain of each amplifier is controlled as a function of the output difference when the channel is connected periodically to each of a pair of Dicke noise sources, such as resistors maintained at predetermined temperatures.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 43
    facet.materialart.
    Unknown
    Rough surface wavelength measurement through self mixing of Doppler microwave backscatter (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A microwave backscatter technique is presented that has the ability to sense the dominant surface wavelength of a random rough surface. The purpose of this technique is to perform this measurement from an aircraft or spacecraft, wherein the horizontal velocity of the radar is an important parameter of the measurement system. Attention will be directed at water surface conditions for which a dominant wavelength can be defined, then the spatial variations of reflectivity will have a two dimensional spectrum that is sufficiently close to that of waves to be useful. The measurement concept is based on the relative motion between the water waves and a nadir looking radar, and the fact that while the instantaneous Doppler frequency at the receiver returned by any elementary group of scatterers on a water wave is monotonically changing, the difference in the Doppler frequency between any two scattering 'patches' stays approximately constant as these waves travel parallel to the major axis of an elliptical antenna footprint. The results of a theoretical analysis and a laboratory experiment with a continuous wave (CW) radar that encompasses several of the largest waves in the illuminated area show how the structure in the Doppler spectrum of the backscattered signal is related to the surface spectrum and its parameters in an especially direct and simple way when an incoherent envelope detector is the receiver.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Transactions on Antennas and Propagation; AP-27; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 44
    facet.materialart.
    Unknown
    Fiber Ring Optical Gyroscope (FROG) (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The design, construction, and testing of a one meter diameter fiber ring optical gyro, using 1.57 kilometers of single mode fiber, are described. The various noise components: electronic, thermal, mechanical, and optical, were evaluated. Both dc and ac methods were used. An attempt was made to measure the Earth rotation rate; however, the results were questionable because of the optical and electronic noise present. It was concluded that fiber ring optical gyroscopes using all discrete components have many serious problems that can only be overcome by discarding the discrete approach and adapting an all integrated optic technique that has the laser source, modulator, detector, beamsplitters, and bias element on a single chip.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-163387 , PUBL-79-014
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 45
    facet.materialart.
    Unknown
    Pressure Modulator Radiometer (PMR) tests (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The pressure modulator technique was evaluated for monitoring pollutant gases in the Earth's atmosphere of altitude levels corresponding to the mid and lower troposphere. Using an experimental set up and a 110 cm sample cell, pressure modulator output signals resulting from a range of gas concentrations in the sample cell were examined. Then a 20 cm sample cell was modified so that trace gas properties in the atmosphere could be simulated in the laboratory. These gas properties were measured using an infrared sensor.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-159175
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 46
    facet.materialart.
    Unknown
    Displacement probes with self-contained exciting medium (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A transducer that combines a noncontacting displacement probe with a self-contained target is described. The target is held in position against a vibrating surface by a housing which also supports the noncontacting probe. The target vibrates with the surface and the probe senses the vibrations of the target.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 47
    facet.materialart.
    Unknown
    Instrument error analysis as it applies to wind-tunnel testing (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Errors resulting from the instrumentation used to measure wind tunnel model parameters are analyzed. The pertinent parameters, their standard deviations, and the theoretical derivation of them, are given. Some BASIC programs and plots for the standard deviations of dynamic pressure, Mach number, and Reynolds number are included.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TP-1572 , L-13222
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 48
    facet.materialart.
    Unknown
    A low energy electron magnetometer (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The concept of a highly sensitive magnetometer based on the deflection of low energy electron beams in magnetic fields is analyzed. Because of its extremely low mass and consequently high e/m ratio, a low energy electron is easily deflected in a magnetic field, thus providing a basis for very low field measurement. Calculations for a specific instrument design indicate that a low energy electron magnetometer (LEEM) can measure magnetic fields as low as 1000 nT. The anticipated performance of LEEM is compared with that of the existing high resolution magnetometers in selected applications. The fast response time of LEEM makes it especially attractive as a potential instrument for magnetic signature analysis in large engineering systems.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-80172 , L-13329
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 49
    facet.materialart.
    Unknown
    Determination of noise equivalent reflectance for a multispectral scanner: A scanner sensitivity study (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The methods used to calculate the sensitivity parameter noise equivalent reflectance of a remote-sensing scanner are explored, and the results are compared with values measured over calibrated test sites. Data were acquired on four occasions covering a span of 4 years and providing various atmospheric conditions. One of the calculated values was based on assumed atmospheric conditions, whereas two others were based on atmospheric models. Results indicate that the assumed atmospheric conditions provide useful answers adequate for many purposes. A nomograph was developed to indicate sensitivity variations due to geographic location, time of day, and season.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TP-1575 , S-497
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 50
    facet.materialart.
    Unknown
    Experimental study of low-energy charge transfer in nitrogen (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Total charge transfer cross sections were obtained for the N2(+)-N2 system with relative translational ion energies between 9 and 441 eV. Data were obtained to examine the dependence of total cross section on ion energy. The effect of ion excitation on the cross sections was studied by varying the electron ionization energy in the mass spectrometer ion source over an electron energy range between 14.5 and 32.1 eV. The dependence of total cross section on the neutralization chamber gas pressure was examined by obtaining data at pressure values from 9.9 to 0.000199 torr. Cross section values obtained were compared with experimental and theoretical results of other investigations.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-80156 , L-13246
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 51
    facet.materialart.
    Unknown
    Calibration of long wavelength Exotech model 20C spectroradiometer (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A brief description of the Exotech model 20C field spectroradiometer, which measures the spectral radiance of a target in the wavelength ranges from 0.37 to 2.5 microns (short wavelength unit), 2.8 to 5.6 microns, and 7.0 to 14 microns (long wavelength unit) is given. It is a rugged field instrument which uses four circular-variable-filters to get wavelength scan. Wavelength calibration of the long wavelength unit was done by use of the strong, sharp, and accurately known absorption bands of polystyrene, atmospheric carbon dioxide, and methyl cyclohexane (liquid) in the IR wavelength region. The spectral radiance calibration was done by recording spectral scans of the hot and the cold blackbody targets and assuming that spectral radiance varies linearly with the signal.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; July 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 52
    facet.materialart.
    Unknown
    A far-infrared photometer for the Kuiper Airborne Observatory (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A high-angular-resolution multiaperture far-IR photometric instrument for multicolor observations of a variety of objects at effective wavelengths of 40 to 160 microns is described which is ideal for use on NASA's Kuiper Airborne Observatory. The operational principles of the instrument are discussed, along with the far-IR radiometer and the offset guiding module. System performance is evaluated on the basis of the noise-equivalent flux of the radiometer, guiding accuracy capability, the suitability to the scientific objectives of the filter bandpasses and focal-plane aperture sizes, the ease of operation, and operating efficiency. Some examples of recent observations with this instrument are provided.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Astronomical Society of the Pacific; vol. 91
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 53
    facet.materialart.
    Unknown
    A liquid-helium-cooled grating spectrometer for far infrared astronomical observations (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A liquid-helium-cooled grating spectrometer has been developed for low-resolution far-infrared spectrometric measurements of astronomical sources conducted by the 30-cm NASA Lear Jet telescope. Simple MOSFET coupled transimpedance preamplifiers were adopted for the spectrometer design. The infrared spectrometer has resolving powers from 10 to 150 over the wavelength range from 45 to 115 microns.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Astronomical Society of the Pacific; vol. 91
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 54
    facet.materialart.
    Unknown
    Design of an extended-range, three-wavelength distance-measuring instrument (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: The paper describes an extension of current multiwavelength electromagnetic distance measurement (EDM) techniques which should allow the range of multiwavelength measurements to be extended to approximately 50 km. The basic modification needed is the replacement of the retroreflector commonly used by an active station containing lasers and a microwave source. Because the system will always be operated as a full three-wave-length instrument, accuracies of about 5 x 10 to the -8th at 50 km should be obtainable on a routine basis under reasonably clear weather conditions.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Tectonophysics; 52; 1979
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 55
    facet.materialart.
    Unknown
    Sealed position sensitive hard X-ray detector having large drift region for all sky camera with high angular resolution (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A sealed position sensitive proportional counter filled with two atmospheres of 95% xenon and 5% methane, and containing a drift region of 24 atm cm, has operated in a stable manner for many months. The detector contains G-10 frames to support the anode and cathode wires. The detector was sealed successfully by a combination of vacuum baking the G-10 frames at 150 C for two weeks followed by assembly into the detector in an environment of dry nitrogen, and the use of passive internal getters. The counter is intended for use with a circumferential cylindrical collimator. Together they provide a very broad field of view detection system with the ability to locate cosmic hard X-ray and soft gamma ray sources to an angular precision of a minute of arc. A set of instruments based on this principle have been proposed for satellites to detect and precisely locate cosmic gamma ray bursts.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 56
    facet.materialart.
    Unknown
    A drift multiwire proportional counter for cosmic soft X-ray imaging (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Multiwire proportional counters with 1 micrometer polypropylene windows, of dimensions 75 mm x 75 mm and 100 mm x 100 mm, have been built to map soft cosmic X-rays. The counters are constructed with a large drift region which makes it possible to use the center-of-gravity technique to improve the counter's efficiency and position resolution. Using 330 torr of propane as the gas fill and an anode plane composed of 20 micrometer diameter, gold-plated tungsten wire spaced 1mm apart, a position resolution of better than 280 micrometers (FWHM) in two orthogonal directions at an X-ray energy of 0.94 keV was achieved.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 57
    facet.materialart.
    Unknown
    Continuous discharge Penning source with emission lines between 50 A and 300 A (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: The present paper deals with a modified Penning discharge lamp developed specially to cover the soft X-ray and extreme UV spectral regions. The source produces a total of nearly 40 intense lines in the 50 to 300 A range. The lamp is quiet, continuous, and stable over most of the cathode lifetime (which is sufficient for long calibration runs). When the cathodes become exhausted, the refurbishment procedure is so simple that the source can be back on line in an hour or less
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Mar. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 58
    facet.materialart.
    Unknown
    Kitt Peak speckle camera (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: The speckle camera in regular use at Kitt Peak National Observatory since 1974 is described in detail. The design of the atmospheric dispersion compensation prisms, the use of film as a recording medium, the accuracy of double star measurements, and the next generation speckle camera are discussed. Photographs of double star speckle patterns with separations from 1.4 sec of arc to 4.7 sec of arc are shown to illustrate the quality of image formation with this camera, the effects of seeing on the patterns, and to illustrate the isoplanatic patch of the atmosphere.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Apr. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 59
    facet.materialart.
    Unknown
    Correction of instrumental distortion by analytical deconvolution of data (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A general analytical theorem developed by van de Hulst (1946) for inverting the convolution integral is reviewed and illustrated both with synthetic data and with experimental data from time-of-flight measurements. If the undesired influence of an instrument used in an experimental measurement can be represented by the convolution integral, the original undistorted or true distribution may sometimes be recovered in postprocessing the data by means of deconvolution. Analytical deconvolution is achieved by using the coefficients from a power series representation of the distorted output distribution and a set of 'solving polynomials' which may be readily derived from the response function of the instrument.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Journal of Chemical Physics; 70; Mar. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 60
    facet.materialart.
    Unknown
    Optimum frequencies of passive microwave radiometer for tropospheric path-length correction (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Radio-astronomical observations require accurate calibration of tropospheric path length. Such calibration can be achieved by microwave radiometers operating near the 22-GHz water vapor line. However, the performances of current passive microwave radiometers are meteorology-profile dependent. This is due mainly to incorrect frequency combinations and to saturation of brightness temperatures. By properly selecting an optimum frequency pair and removing the saturation effect, the dependency is alleviated and can be further adjusted by surface measurements alone. Hence, a universal calibration equation is applicable to all environmental conditions. Optimum frequency pairs are systematically searched. Simulation analysis indicates that calibration for the tropospheric water-vapor path-length error is better than 0.3 cm at zenith and better than 2 cm for an elevation angle as low as 10 deg.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Transactions on Antennas and Propagation; AP-27; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 61
    facet.materialart.
    Unknown
    Geometries and focal properties of two electron-lens systems useful in low-energy electron or ion scattering (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Geometries and focal properties are given for two types of electron-lens system commonly needed in electron scattering. One is an electron gun that focuses electrons from a thermionic emitter onto a fixed point (target) over a wide range of final energies. The other is an electron analyzer system that focuses scattered electrons of variable energy onto a fixed position (e.g., the entrance plane of an analyzer) at fixed energy with a zero final beam angle. Analyzer-system focusing properties are given for superelastically, elastically, and inelastically scattered electrons. Computer calculations incorporating recent accurate tube-lens focal properties are used to compute lens voltages, locations and diameters of all pupils and windows, filling factors, and asymptotic rays throughout each lens system. Focus voltages as a function of electron energy and energy change are given, and limits of operation of each system discussed. Both lens systems have been in routine use for several years, and good agreement has been consistently found between calculated and operating lens voltages.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Review of Scientific Instruments; 50; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 62
    facet.materialart.
    Unknown
    Improvement of scanning radiometer performance by digital reference averaging (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Most radiometers utilize a calibration technique in which measurements of a known reference are subtracted from measurements of an unknown source so that common-mode bias errors are cancelled. When a radiometer is scanned over a varying scene, it produces a sequence of outputs, each being proportional to the difference between the reference and the corresponding input. A reference averaging technique is presented that employs a simple digital algorithm which exploits the asymmetry between the time-variable scene inputs and the nominally constant reference input by averaging many reference measurements to decrease the statistical uncertainty in the reference value. This algorithm is, therefore, optimized by an asymmetric chopping sequence in which the scene is viewed for more than one-half of the duty cycle (unlike the analog Dicke technique). Reference averaging algorithms are well within the capabilities of small microprocessors. Although this paper develops the technique for microwave radiometry, it may be beneficial for any system which measures a large number of unknowns relative to a known reference in the presence of slowly varying common-mode errors.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Transactions on Instrumentation and Measurement; IM-28; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 63
    facet.materialart.
    Unknown
    Optical design of the ATMOS Fourier transform spectrometer (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: The optical system design of the ATMOS Fourier transform spectrometer to be operated from Spacelab for the measurement of stratospheric trace molecules is described. The design contains features which can achieve the required fringe contrast of 80% and spectral resolution of 0.02/cm over a spectral range of 2-16 microns. In particular, the design is based on the following features which alleviate the usual requirements for alignment precision: (1) 'cat's eye' mirror configuration in the two arms of the interferometer for retroreflection stability, (2) tilt-compensated system of beamsplitter, compensator, and fold mirrors for wavefront directional stability, (3) paraboloidal 'cat's eye' primary mirror for wavefront stability against shear, (4) rotatable compensator for matching chromatic dispersion, and (5) wedged refractive components to avoid channel spectra due to the Fabry-Perot effect.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Optical systems engineering; August 27, 28, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 64
    facet.materialart.
    Unknown
    The charge injection device /CID/ as a stellar tracking sensor (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: A 128 x 128 element CID imager was operated in a simulated stellar trackling environment and evaluated for temporal and pattern noise and spectral response over a temperature range of -40 C to +25 C. The test devices were fabricated on long-lifetime bulk silicon material and utilized very thin upper-level polysilicon electrodes for enhanced spectral response. A standard microcomputer was used to generate all control signals and to collect and process performance data. The results of this program were used to predict the performance of a 400 x 400 CID array designed specifically for stellar-tracking.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Recent advances in TV sensors and systems; August 27, 28, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 65
    facet.materialart.
    Unknown
    Making real-time sun reflectance measurements with a microprocessor-based spectroradiometer (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: A standard high-speed, field-portable spectroradiometric measurement system built around a programmable microprocessor has been adapted to the form of a Reflectometer/Comparator. In this configuration, the instrument makes passive measurements of the absolute reflectance of agricultural plant canopies over a spectral range of 0.4 to 2.5 micrometers. Real-time absolute measurements are made possible by an optical chopper which constantly compares the target with the sun, and makes extensive measurements of solar reflectance from a variety of these targets. The paper describes the instrumentation and measurement procedures, reviews the software programming and discusses the results.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Real-time signal processing II; April 19, 20, 1979; Washington, D. C.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 66
    facet.materialart.
    Unknown
    Electronic heterodyne recording of interference patterns (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: An electronic heterodyne technique is being investigated for video (i.e., television rate and format) recording of interference patterns. In the heterodyne technique electro-optic modulation is used to introduce a sinusoidal phase shift between the beams of an interferometer. For phase modulation frequencies between 0.1 and 15 MHz an image dissector camera may be used to scan the resulting temporally modulated interference pattern. Heterodyne detection of the camera output is used to selectively record the interference pattern. An advantage of such synchronous recording is that it permits recording of low-contrast fringes in high ambient light conditions. The application of this technique to the recording of holograms is discussed.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Interferometry; August 29, 30, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 67
    facet.materialart.
    Unknown
    Space Telescope Digicon (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: The Digicon, chosen by NASA as the detector for the High Resolution Spectrograph (HRS) and the Faint Object Spectrograph (FOS) is a 512 parallel output channel vacuum photodetector. There are two HRS Digicons with spectral sensitivity ranges from 1050 A to 1800 A and 1150 A to 3000 A respectively, and two FOS Digicons, which have spectral ranges extending to 7000 A. The significant requirements for these devices are 0.01 counts per second background count rate per diode, state-of-the-art Digicon pulse height resolution (typical 15%) and a high degree of imaging precision and stability. The results of a manufacturing and test program to develop the Digicons coupled with extensive prior work has shown that these requirements can be met. The Digicon because of its inherent ruggedness is particularly well suited to space applications.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Recent advances in TV sensors and systems; August 27, 28, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 68
    facet.materialart.
    Unknown
    Electronic recording of holograms with applications to holographic displays (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: The paper describes an electronic heterodyne recording which uses electrooptic modulation to introduce a sinusoidal phase shift between the object and reference wave. The resulting temporally modulated holographic interference pattern is scanned by a commercial image dissector camera, and the rejection of the self-interference terms is accomplished by heterodyne detection at the camera output. The electrical signal representing this processed hologram can then be used to modify the properties of a liquid crystal light valve or a similar device. Such display devices transform the displayed interference pattern into a phase modulated wave front rendering a three-dimensional image.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Advances in display technology; August 29, 30, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 69
    facet.materialart.
    Unknown
    Narrow-field radiometry in a quasi-isotropic atmosphere (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: If a radiometer having a narrow field of view is used to measure the radiance of a source such as a quasi-isotropic atmosphere, a knowledge of the out-of-field responsivity is critical. For example, if a radiometer with a field of view of 5 deg (full-angle) has a relative responsivity of 0.0001 for the out-of-field radiation, the contribution of the out-of-field radiation (assuming an isotropic source subtending 2 steradians) is 10.5% of the total signal. Either the stray light suppression of the radiometer must be extremely high or methods of determining the out-of-field response must be developed. A description of one method of determining the effect of out-of-field response and its application to a planetary atmospheric radiometer is presented.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Measurements of optical radiations; August 29, 30, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 70
    facet.materialart.
    Unknown
    Multiband radiometer for field research (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: A multiband radiometer for field research with 8 bands between 0.4 and 12.5 micrometers is described. The data acquisition system will record the results from the radiometer, a precision radiation thermometer, and ancillary sources. The radiometer and data handling systems will be adaptable to helicopter, truck, to tripod platforms; the system will also be suitable for portable hand-held operation. The general characteristics of this system are that it will be (1) inexpensive to acquire, maintain, and operate, (2) simple to calibrate, (3) complete with data handling hardware and software, and (4) well-documented for use by researchers.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Measurements of optical radiations; August 29, 30, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 71
    facet.materialart.
    Unknown
    Image processing via ultrasonics - Status and promise (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: Acousto-electric devices for electronic imaging of light are discussed. These devices are more versatile than line scan imaging devices in current use. They have the capability of presenting the image information in a variety of modes. The image can be read out in the conventional line scan mode. It can be read out in the form of the Fourier, Hadamard, or other transform. One can take the transform along one direction of the image and line scan in the other direction, or perform other combinations of image processing functions. This is accomplished by applying the appropriate electrical input signals to the device. Since the electrical output signal of these devices can be detected in a synchronous mode, substantial noise reduction is possible
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Optical processing systems; May 22, 23, 1979; Huntsville, AL.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 72
    facet.materialart.
    Unknown
    Focus compensation techniques for reconnaissance (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: To maintain optimum resolution under varying environmental conditions, a focusing compensation system has been developed. The system is capable of detecting not only changes in pressure (altitude) and the general lens temperature but also the radial thermal gradients in the lens. Theoretical considerations show that the lens is most affected by these factors. The developed system uses a laser measurement system with environmental sensors to generate a focus correction for environment and range changes.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Airborne reconnaissance IV; April 17, 18, 1979; Washington, D. C.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 73
    facet.materialart.
    Unknown
    Ge photocapacitive MIS infrared detectors (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: An undoped Ge photocapacitive detector is reported which has peak normalized detectivities at wavelengh 1.4 microns and chopping frequencies 13-1000 Hz of 9 x 10 to the 12th, 4 x 10 to the 9th cm Hz to the 1/2th/W operating respectively at temperatures 77, 195, and 295 K. The observed temperature, spectral, and frequency response of the signal and noise are explained in terms of the measured space charge and interface state properties of the device.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Journal of Applied Physics; 50; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 74
    facet.materialart.
    Unknown
    Preliminary design and development of a reflectance spectrometer instrument (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An improved design for the reflectance spectrometer is described to be used on various terrestrial body missions. These improvements were made on the original Lunar Polar Orbiter design. These include a larger entrance mirror, rectangular aperture, multiple optical beams, spatial resolution, and a bandwidth extension to 5 microns. In addition, detailed electronic designs were produced for a charge amplifier and an amplifier/demodulator/integrator. Design of a microprocessor driven test system was begun. Laboratory tests were performed on a tuning fork chopper.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-158467
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 75
    facet.materialart.
    Unknown
    Apparatus for providing a servo drive signal in a high-speed stepping interferometer (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An analog voltage approximately linearly proportional to a desired offset from the present null position of a moving mirror in an interferometer is applied to the mirror moving means. As the mirror moves to the next null position, as determined by the analog voltage, the fringes of a laser reference interference pattern are detected. At the occurrence of each fringe the analog voltage is reduced proportionally so that when the next null position is reached, this driving analog is effectively zero. A binary up/down counter, by its internal count, causes a digital/analog converter to supply the analog voltage to the mirror moving means. Fringe detection and direction of movement logic cause the binary up/down counter to be decremented from its offset count as the mirror is moved to the new null position. Undesirable movement of the mirror due to vibration or other sources causes a correcting drive signal to be applied to the mirror moving means that is proportional to the distance of movement.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 76
    facet.materialart.
    Unknown
    Active cavity radiometer type IV (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A new cavity pyrheliometer, the active cavity radiometer type IV (ACR IV), has been developed for the measurement of total solar optical irradiance. Analysis predicts its ability to measure at the solar constant level with 0.1% uncertainty in SI units. In comparison tests ACR IVs have consistently demonstrated 0.3% higher results than the World Radiometric Reference scale. A prototype has been tested, and a flight instrument has been developed and flown in a sounding rocket experiment to determine the solar constant. ACR IV instrumentation is being developed for flight experiments on the Spacelab I and Solar Maximum missions to monitor the total solar output of optical radiation as part of a long-term program to detect variations of climatological significance.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Jan. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 77
    facet.materialart.
    Unknown
    Delay compensation - Its effect in reducing sampling errors in Fourier spectroscopy (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: An approximate formula is derived for the spectrum ghosts caused by periodic drive speed variations in a Michelson interferometer. The solution represents the case of fringe-controlled sampling and is applicable when the reference fringes are delayed to compensate for the delay introduced by the electrical filter in the signal channel. Numerical results are worked out for several common low-pass filters. It is shown that the maximum relative ghost amplitude over the range of frequencies corresponding to the lower half of the filter band is typically 20 times smaller than the relative zero-to-peak velocity error, when delayed sampling is used. In the lowest quarter of the filter band it is more than 100 times smaller than the relative velocity error. These values are ten and forty times smaller, respectively, than they would be without delay compensation if the filter is a 6-pole Butterworth.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Jan. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 78
    facet.materialart.
    Unknown
    Evaluation of miniature single-wire sheathed thermocouples for turbine blade temperature measurement (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Chromel Alumel thermocouples were used, with sheath diameters of 0.15 and 0.25 mm. Tests were conducted at temperatures ranging from 750 to 1250 K. Both steady state and thermal cycling tests were performed for times up to 200 hours. Initial testing was performed in a low velocity gas stream for long time periods using a Meker-type burner. Additional testing was done in a high velocity gas stream for short time periods using a hot gas tunnel and also in a J75 jet engine. A total of eleven 0.15 mm diameter thermocouples and six 0.25 mm diameter thermocouples were tested. Drift rates up to 2.5% in 10 hours were observed. Photomicrographs show that this design is near the limit of miniaturization based on present manufacturing capabilities. Results indicate that the effects of miniaturization on reliability and accuracy must be considered when choosing thermocouples for a particular application.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-79173 , E-068
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 79
    facet.materialart.
    Unknown
    Design, development, and test of a laser velocimeter for a small 8:1 pressure ratio centrifugal compressor (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The instrument was designed as a diagnostic tool for the basic fluid dynamics of the inducer, impeller, and diffuser regions of this type compressor. The LV instrumentation was optimized to measure instantaneous velocities up to approximately 500 m/s, measured in absolute coordinates, within the rotating compressor impeller and in the two dimensional radial plane of the diffuser. Some measurements were made within the diffuser and the impeller inlet flows; however, attempts to make detailed measurements of the velocity field were not successful. Difficulties in maintaining high seed particle rates within the probe volume and the improper operation of the blade gating optics may explain the lack of success. Recommendations are made to further pursue these problems. At 100% speed the stage attained a total static pressure ratio of 7.5:1 at 75% total-static efficiency. Flow range from choke-to-surge was 6.8% of choking mass flow rate. Performance was lower than the design intent of 8:1 pressure ratio at 77% efficiency and 12% flow range. Detailed measurements of the stage components are presented which show the reasons for the stage performance deficiencies.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-134781 , CREARE-TN-289
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 80
    facet.materialart.
    Unknown
    Fine particulate capture device (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: To capture fine particulate matter in a gas such as air, a dielectric fluid is directed to the center of whichever face of a rotating disc is exposed to the air flow. The disc is comprised of two or more segments which bear opposite electrostatic potentials. As the dielectric fluid is centrifuged towards the periphery of the rotating disc, the fluid becomes charged to the same potential as the segment over which it is passing. Particulate matter is attracted to the charged segment and is captured by the fluid. The fluid then carries the captured particulate matter to a collection device such as a toroidal container disposed around the periphery of the disc. A grounded electrically-conductive ring may be disposed at the outer periphery of the disc to neutralize the captured particles and the fluid before they enter the container.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 81
    facet.materialart.
    Unknown
    Conditional replenishment using motion prediction (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Conditional replenishment is an interframe video compression method that uses correlation in time to reduce video transmission rates. This method works by detecting and sending only the changing portions of the image and by having the receiver use the video data from the previous frame for the non-changing portion. The amount of compression that can be achieved through this technique depends to a large extent on the rate of change within the image, and can vary from 10 to 1 to less than 2 to 1. An additional 3 to 1 reduction in rate is obtained by the intraframe coding of data blocks using a 2-dimensional variable rate Hadamard transform coder. A further additional 2 to 1 rate reduction is achieved by using motion prediction. Motion prediction works by measuring the relative displacements of a subpicture from one frame to the next. The subpicture can then be transmitted by sending only the value of the 2-dimensional displacement. Computer simulations have demonstrated that data rates of 2 to 4 Mega-bits/second can be achieved while still retaining good fidelity in the image.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applications of digital image processing III; Aug 27, 1979 - Aug 29, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 82
    facet.materialart.
    Unknown
    Multi-anode microchannel arrays (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The Multi-Anode Microchannel Arrays (MAMA's) are a family of photoelectric, photon-counting array detectors being developed for use in instruments on both ground-based and space-borne telescopes. These detectors combine high sensitivity and photometric stability with a high-resolution imaging capability. MAMA detectors can be operated in a windowless configuration at extreme-ultraviolet and soft X-ray wavelengths or in a sealed configuration at ultraviolet and visible wavelengths. Prototype MAMA detectors with up to 512 x 512 pixels are now being tested in the laboratory and telescope operation of a simple (10 x 10)-pixel visible-light detector has been initiated. The construction and modes-of-operation of the MAMA detectors are briefly described and performance data are presented.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Los Alamos Conference on Optics; May 23, 1979 - May 25, 1979; Los Alamos, NM
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 83
    facet.materialart.
    Unknown
    A parametric model for multispectral scanners (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A set of test statistics are specified and the corresponding output quantities computed by the characteristic function. Two sets of classification accuracies, one at the input and one at the output are estimated. The scanner's instantaneous field of view is changed and the variation of the output classification performance is monitored.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Machine processing of remotely sensed data; Jun 27, 1979 - Jun 29, 1979; West Lafayette, IN
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 84
    facet.materialart.
    Unknown
    Cryogenic wind tunnel force instrumentation (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The paper outlines the work that has been accomplished at Langley Research Center (NASA) while investigating the effects of cryogenic environment on one-place multicomponent strain-gage balances. Particular emphasis is placed on cryogenic balances for use in the National Transonic Facility (NTF).
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: International Symposium on Cryogenic Wind Tunnels; Apr 03, 1979 - Apr 05, 1979; Southampton
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 85
    facet.materialart.
    Unknown
    Improved microwave radiometry for remote sensing (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Significant improvements in the gain stability and overall performance of microwave radiometers have been achieved with the use of a self-balancing gain modulation technique. This technique, in combination with automatic thermal calibration, is particularly well suited for remote sensing radiometric applications. The essential features of such a radiometer, including typical data obtained from a spaceborne satellite, is presented to show the instrument's utility.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: European Microwave Conference; Sep 04, 1978 - Sep 08, 1978; Paris; France
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 86
    facet.materialart.
    Unknown
    Thermographic measurement of fatigue damage (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The paper presents a thermographic technique developed to measure the extent of fatigue damage in composite materials during fatigue loading. It is noted that heat generated by cyclic loading of fatigue damaged material raises the surface temperature. These temperatures were measured with an infrared camera and were used as boundary conditions in a finite element heat transfer program, which has been developed especially to calculate the extent of the heat generation zone, and thereby to define the fatigue damage zone. It is reported that the finite element program was verified by comparing calculated heat generation with the actual heat generation for a simple heat transfer problem that had a closed form solution. Damage zones are calculated for several boron/epoxy fatigue specimens from thermograms of specimens. The calculated damage zones were compared with damage detected by C-scan, X-ray, and scanning electron microscope (SEM) examinations. It is concluded that the analysis was effective in locating the boundaries of the fatigue damage zones.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Composite materials: Testing and design; Mar 20, 1978 - Mar 22, 1978; New Orleans, LA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 87
    facet.materialart.
    Unknown
    VLSI system for synthetic aperture radar /SAR/ processing (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The paper discusses an SAR problem based on actual requirements set forth by NASA for a spaceborne application. The requirements for high resolution and high quality necessitate a data sampling rate of 7.5 MHz. For each data value 1,025 4-bit complex multiply + add operations are needed, which is equivalent to 7.7 GHz complex multiply + add operation rate. Since this rate is much too high for general purpose systems, a special-purpose device was sought. This paper discusses two architectures based on parallel operation of 1,025 identical cells, each of which is capable of performing arithmetic, storage, and several control operations. The operation rate in each device is only 7.5 MHz, which is quite manageable, especially with the help of a substantial degree of pipelining. A computational-mathematical analysis is used as a primary tool for evaluating the design and some of its tradeoffs. Two different approaches are discussed and compared; both are based on having 1,025 identical cells working in parallel, but differ in their dual approaches to the flow of data.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Digital processing of aerial images; May 22, 1979 - May 24, 1979; Huntsville, AL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 88
    facet.materialart.
    Unknown
    Imaging proportional counter for X-ray astronomy (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A position-sensitive proportional counter capable of imaging X-rays (0.1-3 keV) over a 10 cm x 10 cm aperture has been constructed. Positioning is obtained by sensing the signals induced by an X-ray event on the two orthogonal sets of cathode wires. Each cathode is divided into a series of cathode strips, each 0.5 cm wide. An X-ray event induces signals on several adjacent strips. Signals from each cathode strip are amplified separately and then added in an equally weighted and an unequally weighted summing amplifier. The position in each direction is obtained by dividing the output of the unequally weighted summer by that of the equally weighted summer. At 0.94 keV, the accuracy of the position sensing is 190 microns. At the same energy, the energy resolution is approximately 65% (FWHM). The proportional counter system is currently being incorporated into a sounding rocket payload having metal mirror optics, which is being constructed by the X-ray astronomy group at the California Institute of Technology.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Space optics: Imaging X-ray optics workshop; May 22, 1979 - May 24, 1979; Huntsville, AL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 89
    facet.materialart.
    Unknown
    Thematic mapper design description and performance prediction (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The new generation of satellite-borne earth resources scanners, the Thematic Mapper, is being built for launch on the Landsat-D spacecraft. It will gather data for applications such as crop inventory, land use planning, forest management, and geology. This paper gives an overall design description, further discussion of principal design features, performance achievements where data are available, and system performance predictions.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Space optics; May 22, 1979 - May 24, 1979; Huntsville, AL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 90
    facet.materialart.
    Unknown
    Multispectral Resource Sampler - An experimental satellite sensor for the mid-1980s (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: An experimental pushbroom scan sensor, the Multispectral Resource Sampler (MRS), being developed by NASA for a future earth orbiting flight is presented. This sensor will provide new earth survey capabilities beyond those of current sensor systems, with a ground resolution of 15 m over a swath width of 15 km in four bands. The four arrays are aligned on a common focal surface requiring no beamsplitters, thus causing a spatial separation on the ground which requires computer processing to register the bands. Along track pointing permits stereo coverage at variable base/height ratios and atmospheric correction experiments, while across track pointing will provide repeat coverage, from a Landsat-type orbit, of every 1 to 3 days. The MRS can be used for experiments in crop discrimination and status, rock discrimination, land use classification, and forestry.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Space optics; May 22, 1979 - May 24, 1979; Huntsville, AL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 91
    facet.materialart.
    Unknown
    Selenium immersed thermistor bolometer study (1979)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The noise characteristics of thermistor bolometers immersed in layers of arsenic/selenium glass uniform in composition were examined. Using a controlled deposition technique, layers of glass were deposited, thermistor bolometers immersed, and their electrical characteristics measured after various thermal treatments. Markedly improved stability of the detector noise was observed using this new technique.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-160013 , BEC-2774
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 92
    facet.materialart.
    Unknown
    Efficient laser anemometer for intra-rotor flow mapping in turbomachinery (1979)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A fringe type laser anemometer is described. Features of the anemometer include; a rapid and efficient data acquisition process; a detailed real time graphic display of the data being accumulated; and input laser beam positioning that maximizes the size of the intrarotor region being mapped. Results are presented that demonstrate the anemometer's capability in flow mapping within a transonic axial flow compressor rotor. A velocity profile, derived from 30,000 measurements along 1000 sequential circumferential positions covering 20 blade passages, was obtained in 30 seconds. The use of fluorescent seed particles allowed flow measurements near the rotor hub and the casing window.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-79320 , E-276 , ASME 25th Ann. Intern. Gas Turbine Conf.; Mar 09, 1980 - Mar 13, 1980; New Orleans
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 93
    facet.materialart.
    Unknown
    Spectral feature classification and spatial pattern recognition (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: This paper introduces a spatial pattern recognition processing concept involving the use of spectral feature classification technology and coherent optical correlation. The concept defines a hybrid image processing system incorporating both digital and optical technology. The hybrid instrument provides simplified pseudopattern images as functions of pixel classification from information embedded within a real-scene image. These pseudoimages become simplified inputs to an optical correlator for use in a subsequent pattern identification decision useful in executing landmark pointing, tracking, or navigating functions. Real-time classification is proposed as a research tool for exploring ways to enhance input signal-to-noise ratio as an aid in improving optical correlation. The approach can be explored with developing technology, including a current NASA Langley Research Center technology plan that involves a series of related Shuttle-borne experiments. A first-planned experiment, Feature Identification and Location Experiment (FILE), is undergoing final ground testing, and is scheduled for flight on the NASA Shuttle (STS2/flight OSTA-1) in 1980. FILE will evaluate a technique for autonomously classifying earth features into the four categories: bare land; water; vegetation; and clouds, snow, or ice.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Society of Photo-Optical Instrumentation Engineers, Annual International Technical Symposium and Instrument Display; Aug 27, 1979 - Aug 30, 1979; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 94
    facet.materialart.
    Unknown
    Ge:Ga testing at Cornell (1979)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The spiking and memory behavior of a number of Ge:Ga detectors was studied. The detectors were manufactured at a number of locations using several different contacting techniques. Two detectors manufactured for the IRAS program by Rockwell International were studied more extensively than the others. These detectors IRD 1981 and IRD 1982 were 'witness sample' detectors for the IRAS bands 4 and 3, respectively. During the testing period both the apparatus and the test procedures were changed numerous times. At each change consistency checks were made. The data are believed to be internally consistent from end to end.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-158348 , CRSR-716
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 95
    facet.materialart.
    Unknown
    A versatile burst generator for LDV (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A laser-Doppler velocimeter (LDV) burst generator developed for calibration of an LDV before an actual test is described. This generator uses voltage-controlled oscillators to produce the information frequency up to 1 MHz and the pedestal frequency up to 10 MHz. The amplitude and the frequency of each signal can be adjusted independently, and the generator is capable of producing a single burst or a variety of periodic and aperiodic bursts. Variable symmetry in the burst signal can be introduced to the point of producing the 'double-pulse' burst. An LED display is used for the readout of the information and the pedestal frequencies.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: SOUTHEASTCON ''79; Region 3 Conference and Exhibit; Apr 01, 1979 - Apr 04, 1979; Roanoke, VA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 96
    facet.materialart.
    Unknown
    Alternative signal processing techniques for a pulsed laser Doppler velocimeter system (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The laser Doppler velocimeter system (LDV) being tested at NASA MSFC, Alabama, relies on a bank of classical filters for processing the returned lidar signal. Due to the complexity of this conventional filter system, alternative signal processing methods have been proposed for obtaining the Doppler spectrum. The fast Fourier transform (FFT) and the pulse-pair estimator are two techniques which appear to offer some advantages over the existing system. The work reported employs digital computer simulation to compare and evaluate these two processing methods for determining the first and second moments of the LDV velocity spectrum.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: SOUTHEASTCON ''79; Region 3 Conference and Exhibit; Apr 01, 1979 - Apr 04, 1979; Roanoke, VA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 97
    facet.materialart.
    Unknown
    Laser velocimetry and holographic interferometry measurements in transonic flows (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Measurements of the transonic flow about a two-dimensional airfoil have been made with holographic interferometry and laser velocimetry. Quantitative data obtained with the interferometer are compared to the laser velocimeter and surface pressure measurements to evaluate the accuracy of the technique. Good agreement in the results confirmed the two-dimensionality of the flow and the potential of the interferometer in making unsteady transonic flow measurements in the future.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Laser velocimetry and particle sizing; Third International Workshop; Jul 11, 1978 - Jul 13, 1978; West Lafayette, IN
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 98
    facet.materialart.
    Unknown
    Laser Doppler velocity measurements in subsonic, transonic, and supersonic turbulent boundary layers (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Recent measurements have used laser Doppler velocimetry to make direct measurements of the Reynolds stress in turbulent boundary layers in the Mach number range 1.5 to 3.0. A serious anomaly, however, is exhibited in these measurements in that the maximum of -u-prime v-prime occurs much farther from the wall than is reasonable for flow at constant pressure. The purpose of the present experiments was to obtain redundant data over a substantial range of Mach numbers (0.1-2.2) in an effort to resolve the anomaly in turbulent shearing stress.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Laser velocimetry and particle sizing; Third International Workshop; Jul 11, 1978 - Jul 13, 1978; West Lafayette, IN
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 99
    facet.materialart.
    Unknown
    Time-dependent local density measurements in unsteady flows (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A laser-induced fluorescence technique for measuring the relative time-dependent density fluctuations in unsteady or turbulent flows is demonstrated. Using a 1.5-W continuous-wave Kr(+) laser, measurements have been obtained in 0.1-mm diameter by 1-mm-long sampling volumes in a Mach 3 flow of N2 seeded with biacetyl vapor. A signal amplitude resolution of 2% was achieved for a detection frequency bandwidth of 10 kHz. The measurement uncertainty was found to be dominated by noise behaving as photon statistical noise. The practical limits of signal-to-noise ratios have been characterized for a wide range of detection frequency bandwidths that encompasses those of interest in supersonic turbulence measurements.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: AIAA PAPER 79-1088 , American Institute of Aeronautics and Astronautics, Thermophysics Conference; Jun 04, 1979 - Jun 06, 1979; Orlando, FL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 100
    facet.materialart.
    Unknown
    The application of laser Rayleigh scattering to gas density measurements in hypersonic helium flows (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Measurements of the mean static free-stream gas density have been made in two Langley Research Center helium facilities, the 3-inch leg of the high-Reynolds-number helium complex and the 22-inch hypersonic helium tunnel. Rayleigh scattering of a CW argon ion laser beam at 514.5 nm provided the basic physical mechanism. The behavior of the scattered signal was linear, confirmed by a preliminary laboratory study. That study also revealed the need to introduce baffles to reduce stray light. A relatively simple optical system and associated photon-counting electronics were utilized to obtain data for densities from 10 to the 23rd to 10 to the 25th per cu m. The major purpose, to confirm the applicability of this technique in the hypersonic helium flow, was accomplished.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: AIAA PAPER 79-1086 , American Institute of Aeronautics and Astronautics, Thermophysics Conference; Jun 04, 1979 - Jun 06, 1979; Orlando, FL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...