Vidicon intensifier

NASA Technical Reports Server (NTRS)

Carpentier, R. P.; Pietrzyk, J. P.; Beyer, R. R.; Kalafut, J. S.

1976-01-01

Computer-designed sensor, consisting of single-stage electrostatically-focused, triode image intensifier, provides high quality imaging characterized by exceptionally low geometric distortion, low shading, and high center-and-corner modulation transfer function.

Antares Reference Telescopes System

NASA Astrophysics Data System (ADS)

Viswanathan, V. K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

1983-11-01

Antares is a 24-beam, 40-TW carbon-dioxide laser fusion system currently nearing completion at the Los Alamos National Laboratory. The 24 beams will be focused onto a tiny target (typically 300-1000 pm in diameter) located approximately at the center of a 7.3-m diameter by 9.3-m long vacuum (10-6 torr) chamber. The design goal is to position the targets to within 10 μm of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares Reference Telescope System is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares Reference Telescope System consists of two similar electro-optical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: 1) a fixed 9X optical imaging subsystem which produces an image of the target at the vidicon; 2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; 3) an adjustable front-lighting subsystem which illuminates tne target; and 4) an adjustable back-lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and trade-offs are discussed. The final system chosen (which is being built) and its current status are described in detail.

Extreme Ultraviolet Solar Images Televised In-Flight with a Rocket-Borne SEC Vidicon System.

PubMed

Tousey, R; Limansky, I

1972-05-01

A TV image of the entire sun while an importance 2N solar flare was in progress was recorded in the extreme ultraviolet (XUV) radiation band 171-630 A and transmitted to ground from an Aerobee-150 rocket on 4 November 1969 using S-band telemetry. The camera tube was a Westinghouse Electric Corporation SEC vidicon, with its fiber optic faceplate coated with an XUV to visible conversion layer of p-quaterphenyl. The XUV passband was produced by three 1000-A thick aluminum filters in series together with the platinized reflecting surface of the off-axis paraboloid that imaged the sun. A number of images were recorded with integration times between 1/30 see and 2 sec. Reconstruction of pictures was enhanced by combining several to reduce the noise.

Recent developments and applications of the SEC vidicon for astronomy

NASA Technical Reports Server (NTRS)

Zucchino, P.; Lowrance, J. L.

1971-01-01

The engineering development of the SEC vidicon as an astronomical sensor has continued in parallel with its operational use. One scientific application was the six hour exposure of the quasar PHL-957 at the Coude spectrograph of the 200-inch Hale telescope. The developmental effort includes both the enhancement of the basic attributes that make the SEC an appropriate sensor, namely, high quantum efficiency, low threshold, and long integration; as well as work to broaden its scientific usefulness, such as the development of a MgF2 photocathode window for vacuum ultraviolet sensitivity, and a permanent magnet focus design for thermal compatibility with proposed large space telescopes. Additional details on the characteristics of the SEC tube are discussed, as well as plans to make a larger and higher resolution version.

Closed circuit TV system monitors welding operations

NASA Technical Reports Server (NTRS)

Gilman, M.

1967-01-01

TV camera system that has a special vidicon tube with a gradient density filter is used in remote monitoring of TIG welding of stainless steel. The welding operations involve complex assembly welding tools and skates in areas of limited accessibility.

Digital cartography of Io

NASA Technical Reports Server (NTRS)

Mcewen, Alfred S.; Duck, B.; Edwards, Kathleen

1991-01-01

A high resolution controlled mosaic of the hemisphere of Io centered on longitude 310 degrees is produced. Digital cartographic techniques were employed. Approximately 80 Voyager 1 clear and blue filter frames were utilized. This mosaic was merged with low-resolution color images. This dataset is compared to the geologic map of this region. Passage of the Voyager spacecraft through the Io plasma torus during acquisition of the highest resolution images exposed the vidicon detectors to ionized radiation, resulting in dark-current buildup on the vidicon. Because the vidicon is scanned from top to bottom, more charge accumulated toward the bottom of the frames, and the additive error increases from top to bottom as a ramp function. This ramp function was removed by using a model. Photometric normalizations were applied using the Minnaert function. An attempt to use Hapke's photometric function revealed that this function does not adequately describe Io's limb darkening at emission angles greater than 80 degrees. In contrast, the Minnaert function accurately describes the limb darkening up to emission angles of about 89 degrees. The improved set of discrete camera angles derived from this effort will be used in conjunction with the space telemetry pointing history file (the IPPS file), corrected on 4 or 12 second intervals to derive a revised time history for the pointing of the Infrared Interferometric Spectrometer (IRIS). For IRIS observations acquired between camera shutterings, the IPPS file can be corrected by linear interpolation, provided that the spacecraft motions were continuous. Image areas corresponding to the fields of view of IRIS spectra acquired between camera shutterings will be extracted from the mosaic to place the IRIS observations and hotspot models into geologic context.

Wide-Angle, Flat-Field Telescope

NASA Technical Reports Server (NTRS)

Hallam, K. L.; Howell, B. J.; Wilson, M. E.

1987-01-01

All-reflective system unvignetted. Wide-angle telescope uses unobstructed reflecting elements to produce flat image. No refracting elements, no chromatic aberration, and telescope operates over spectral range from infrared to far ultraviolet. Telescope used with such image detectors as photographic firm, vidicons, and solid-state image arrays.

Space based topographic mapping experiment using Seasat synthetic aperture radar and LANDSAT 3 return beam vidicon imagery

NASA Technical Reports Server (NTRS)

Mader, G. L.

1981-01-01

A technique for producing topographic information is described which is based on same side/same time viewing using a dissimilar combination of radar imagery and photographic images. Common geographic areas viewed from similar space reference locations produce scene elevation displacements in opposite direction and proper use of this characteristic can yield the perspective information necessary for determination of base to height ratios. These base to height ratios can in turn be used to produce a topographic map. A test area covering the Harrisburg, Pennsylvania region was observed by synthetic aperture radar on the Seasat satellite and by return beam vidicon on by the LANDSAT - 3 satellite. The techniques developed for the scaling re-orientation and common registration of the two images are presented along with the topographic determination data. Topographic determination based exclusively on the images content is compared to the map information which is used as a performance calibration base.

LANDSAT-1 flight evaluation report

NASA Technical Reports Server (NTRS)

1975-01-01

Flight performance analysis for the tenth quarter of operation orbit 11467 to 12745 of LANDSAT 1 are presented. Payload subsystems discussed include: power subsystem; attitude control subsystem; telemetry subsystem; electrical interface subsystem; narrowband tape recorders; wideband telemetry subsystem; return beam vidicon subsystem; multispectral scanner subsystem; and data collection system.

Observation of a possible optical burst of the double star Beta Camelopardalis

NASA Technical Reports Server (NTRS)

Wdowiak, T. J.; Clifton, K. S.

1985-01-01

An intensified SEC Vidicon observation of a brightening of the image of Beta Cam for a duration of about 0.25 sec at 0932 UT on December 4, 1969 is described. The observation was made during airborne observations of meteors over Canada between latitudes of 50 and 60 deg N.

Observation of a possible optical burst of the double star Beta Camelopardalis

NASA Astrophysics Data System (ADS)

Wdowiak, T. J.; Clifton, K. S.

1985-08-01

An intensified SEC Vidicon observation of a brightening of the image of β Cam for a duration of ≡0s.25 at 0932 UT on 1969 December 4 is described. The observation was made during airborne observations of meteors over Canada between latitudes of 50° and 60°N.

Martian extratropical cyclones

NASA Technical Reports Server (NTRS)

Hunt, G. E.; James, P. B.

1979-01-01

Physical properties of summer-season baroclinic waves on Mars are discussed on the basis of vidicon images and infrared thermal mapping generated by Viking Orbiter 1. The two northern-hemisphere storm systems examined here appear to be similar to terrestrial mid-latitude cyclonic storms. The Martian storm clouds are probably composed of water ice, rather than dust or CO2 ice particles.

Survey of United States Commercial Satellites in Geosynchronous Earth Orbit

DTIC Science & Technology

1994-09-01

248 a. Imaging Sensors ...... ............ 248 (1) Return Beam Vidicon Camera . ... 249 (2) Scanners. ...... ............ 249 b. Nonimaging ...251 a. Imaging Microwave Sensors ......... .. 251 (1) Synthetic Aperture Radar . ... 251 b. Nonimaging Microwave Sensors ..... .. 252 (1) Radar...The stream of electrons travels alonq the axis oa the tube, constrained by focusing magnets, until it reaches the collector . Surrounding this electron

Systematic Study of Pyroelectricity. Light Scattering and Pyroelectricity in Ferroelectrics

DTIC Science & Technology

1976-04-01

6 compares the experimental X(Z:)X spectrum near 430 cm with the prediction of Eq. (2) to which a slowly varying background has been...Molecular field theory, Triglycine sulfate, Potassium niobate, Raman scattering, vidicons 20. ABSTRACT (Continue on reverie tide II neceeeary and...ray and neutron scattering studies and which provides the starting point for the generalized molecular field theory of ferroelectricity proposed

EXPERIMENTS IN LITHOGRAPHY FROM REMOTE SENSOR IMAGERY.

USGS Publications Warehouse

Kidwell, R. H.; McSweeney, J.; Warren, A.; Zang, E.; Vickers, E.

1983-01-01

Imagery from remote sensing systems such as the Landsat multispectral scanner and return beam vidicon, as well as synthetic aperture radar and conventional optical camera systems, contains information at resolutions far in excess of that which can be reproduced by the lithographic printing process. The data often require special handling to produce both standard and special map products. Some conclusions have been drawn regarding processing techniques, procedures for production, and printing limitations.

Performing and updating an inventory of Oregon's expanding irrigated agricultural lands utilizing remote sensing technology

NASA Technical Reports Server (NTRS)

Hall, M. J.

1981-01-01

An inventory technique based upon using remote sensing technology, interpreting both high altitude aerial photography and LANDSAT multispectral scanner imagery, is discussed. It is noted that once the final land use inventory maps of irrigated agricultural lands are available and approximately scaled they may be overlaid directly onto either multispectral scanner or return beam vidicon prints, thereby providing an inexpensive updating procedure.

Development of an Airborne High Resolution TV System (AHRTS)

DTIC Science & Technology

1975-11-01

GOVT ACCESSION NO READ INSTRUCTIONS BEFORE COMPLETING FORM JP RECIPIENT’S CATALOG NUMBER DEVELOPMENT OF AN ^IRBORNE HIGH JESOLUTION TV SYSTEM...c. Sytem Elements The essential Airborne Subsystem elements of camera, video tape recorder, transmitter and antennas are required to have...The camera operated over the 3000:1 light change as required. A solar shutter was Incorporated to protect the vidicon from damage from direct view

The evolving Alaska mapping program.

USGS Publications Warehouse

Brooks, P.D.; O'Brien, T. J.

1986-01-01

This paper describes the development of mapping in Alaska, the current status of the National Mapping Program, and future plans for expanding and improving the mapping coverage. Research projects with Landsat Multispectral Scanner and Return Vidicon imagery and real- and synthetic-aperture radar; image mapping programs; digital mapping; remote sensing projects; the Alaska National Interest Lands Conservation Act; and the Alaska High-Altitude Aerial Photography Program are also discussed.-from Authors

Making The Invisible Visible

NASA Technical Reports Server (NTRS)

1978-01-01

In public and private archives throughout the world there are many historically important documents that have become illegible with the passage of time. They have faded, been erased, acquired mold, water and dirt stain, suffered blotting or lost readability in other ways. While ultraviolet and infrared photography are widely used to enhance deteriorated legibility, these methods are more limited in their effectiveness than the space-derived image enhancement technique. The aim of the JPL effort with Caltech and others is to better define the requirements for a system to restore illegible information for study at a low page-cost with simple operating procedures. The investigators' principle tools are a vidicon camera and an image processing computer program, the same equipment used to produce sharp space pictures. The camera is the same type as those on NASA's Mariner spacecraft which returned to Earth thousands of images of Mars, Venus and Mercury. Space imagery works something like television. The vidicon camera does not take a photograph in the ordinary sense; rather it "scans" a scene, recording different light and shade values which are reproduced as a pattern of dots, hundreds of dots to a line, hundreds of lines in the total picture. The dots are transmitted to an Earth receiver, where they are assembled line by line to form a picture like that on the home TV screen.

Management of natural resources through automatic cartographic inventory

NASA Technical Reports Server (NTRS)

Rey, P. (Principal Investigator); Gourinard, Y.; Cambou, F.

1972-01-01

The author has identified the following significant results. Return beam vidicon and multispectral band scanner imagery will be correlated with existing vegetation and geologic maps of southern France and northern Spain to develop correspondence codes between map units and space data. Microclimate data from six stations, spectral measurements from a few meters to 2 km using ERTS-type filter and spectrometers, and leaf reflectance measurements will be obtained to assist in correlation studies.

An Improved Electro-Optical Image Quality Summary Measure.

DTIC Science & Technology

1981-10-01

photo- graphing the display of a vidicon camera system viewing silhouettes of the broadside view of a Soviet KOTLIN class destroyer. Observers were...series ,: hard mages. Transparencies of the broadside KOTLIN silhouette were made with the scale :actor ranqin,, from 13b to 1810 meters per picture...3 warship rather than a merchant ship, and (c) the warsh-,;, is identifiable as beinq )f the nDTLIN class. Obviously, since only KOTLIN images were

Landsat-1 and Landsat-2 flight evaluation

NASA Technical Reports Server (NTRS)

1975-01-01

The flight performance of Landsat 1 and Landsat 2 is analyzed. Flight operations of the satellites are briefly summarized. Other topics discussed include: orbital parameters; power subsystem; attitude control subsystem; command/clock subsystem; telemetry subsystem; orbit adjust subsystem; magnetic moment compensating assembly; unified s-band/premodulation processor; electrical interface subsystem; thermal subsystem; narrowband tape recorders; wideband telemetry subsystem; attitude measurement sensor; wideband video tape recorders; return beam vidicon; multispectral scanner subsystem; and data collection subsystem.

Unmanned spacecraft for surveying earth's resources

NASA Technical Reports Server (NTRS)

George, T. A.

1970-01-01

The technical objectives and payloads for ERTS A and B are discussed. The primary emphasis is on coverage of the United States and the ocean areas immediately adjacent, using 3-camera return beam vidicon TV system, 4-channel multispectral point scanner, data collection system, and wideband video tape recorder. The expected performance and system characteristics of the RBV system and the 4-band multispectral object plane point scanner are outlined. Ground station considerations are also given.

Data acquisition system for operational earth observation missions

NASA Technical Reports Server (NTRS)

Deerwester, J. M.; Alexander, D.; Arno, R. D.; Edsinger, L. E.; Norman, S. M.; Sinclair, K. F.; Tindle, E. L.; Wood, R. D.

1972-01-01

The data acquisition system capabilities expected to be available in the 1980 time period as part of operational Earth observation missions are identified. By data acquisition system is meant the sensor platform (spacecraft or aircraft), the sensors themselves and the communication system. Future capabilities and support requirements are projected for the following sensors: film camera, return beam vidicon, multispectral scanner, infrared scanner, infrared radiometer, microwave scanner, microwave radiometer, coherent side-looking radar, and scatterometer.

Earth orbital teleoperator visual system evaluation program

NASA Technical Reports Server (NTRS)

Frederick, P. N.; Shields, N. L., Jr.; Kirkpatrick, M., III

1977-01-01

Visual system parameters and stereoptic television component geometries were evaluated for optimum viewing. The accuracy of operator range estimation using a Fresnell stereo television system with a three dimensional cursor was examined. An operator's ability to align three dimensional targets using vidicon tube and solid state television cameras as part of a Fresnell stereoptic system was evaluated. An operator's ability to discriminate between varied color samples viewed with a color television system was determined.

Optimized Pyroelectric Vidicon Thermal Imager. Volume II. Improper Ferroelectric Crystal Growth.

DTIC Science & Technology

1980-09-01

75 4.1 Hydrothermal Synthesis of Boracite Powders..... 75 4.2 Hydrothermal Growth of Boracite Crystals ......... 77...4.2.1 Apparatus .......................... 77 4.2.2 Growth from Acidic Media .................o 78 4.2.3 Hydrothermal Growth in Basic Media ...... 99...Calculated temperature dependence of p/cc for DSP under biasing fields of 0, 2 and 5 kV/cm... 74 11 LIST OF ILLUSTRATIONS (Cont’d) Page Fig. 44: Hydrothermal

Circular zig-zag scan video format

DOEpatents

Peterson, C. Glen; Simmons, Charles M.

1992-01-01

A circular, ziz-zag scan for use with vidicon tubes. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal.

Integrating TV/digital data spectrograph system

NASA Technical Reports Server (NTRS)

Duncan, B. J.; Fay, T. D.; Miller, E. R.; Wamsteker, W.; Brown, R. M.; Neely, P. L.

1975-01-01

A 25-mm vidicon camera was previously modified to allow operation in an integration mode for low-light-level astronomical work. The camera was then mated to a low-dispersion spectrograph for obtaining spectral information in the 400 to 750 nm range. A high speed digital video image system was utilized to digitize the analog video signal, place the information directly into computer-type memory, and record data on digital magnetic tape for permanent storage and subsequent analysis.

An accurate registration technique for distorted images

NASA Technical Reports Server (NTRS)

Delapena, Michele; Shaw, Richard A.; Linde, Peter; Dravins, Dainis

1990-01-01

Accurate registration of International Ultraviolet Explorer (IUE) images is crucial because the variability of the geometrical distortions that are introduced by the SEC-Vidicon cameras ensures that raw science images are never perfectly aligned with the Intensity Transfer Functions (ITFs) (i.e., graded floodlamp exposures that are used to linearize and normalize the camera response). A technique for precisely registering IUE images which uses a cross correlation of the fixed pattern that exists in all raw IUE images is described.

Determination of lunar ilmenite abundances from remotely sensed data

NASA Technical Reports Server (NTRS)

Larson, Stephen M.; Johnson, Jeffrey R.; Singer, Robert B.

1991-01-01

The mineral ilmenite (FeTiO3) was found in abundance in lunar mare soils returned during the Apollo project. Lunar ilmenite often contains greater than 50 weight-percent titanium dioxide (TiO2), and is a primary potential resource for oxygen and other raw materials to supply future lunar bases. Chemical and spectroscopic analysis of the returned lunar soils produced an empirical function that relates the spectral reflectance ratio at 400 and 560 nm to the weight percent abundance of TiO2. This allowed mapping of the lunar TiO2 distribution using telescopic vidicon multispectral imaging from the ground; however, the time variant photometric response of the vidicon detectors produced abundance uncertainties of at least 2 to 5 percent. Since that time, solid-state charge-coupled device (CCD) detector technology capable of much improved photometric response has become available. An investigation of the lunar TiO2 distribution was carried out utilizing groundbased telescopic CCD multispectral imagery and spectroscopy. The work was approached in phases to develop optimum technique based upon initial results. The goal is to achieve the best possible TiO2 abundance maps from the ground as a precursor to lunar orbiter and robotic sample return missions, and to produce a better idea of the peak abundances of TiO2 for benefaction studies. These phases and the results are summarized.

Imaging of Mercury and Venus from a flyby

USGS Publications Warehouse

Murray, B.C.; Belton, M.J.S.; Danielson, G. Edward; Davies, M.E.; Kuiper, G.P.; O'Leary, B. T.; Suomi, V.E.; Trask, N.J.

1971-01-01

This paper describes the results of study of an imaging experiment planned for the 1973 Mariner Venus/Mercury flyby mission. Scientific objectives, mission constraints, analysis of alternative systems, and the rationale for final choice are presented. Severe financial constraints ruled out the best technical alternative for flyby imaging, a film/readout system, or even significant re-design of previous Mariner vidicon camera/tape recorder systems. The final selection was a vidicon camera quite similar to that used for Mariner Mars 1971, but with the capability of real time transmission during the Venus and Mercury flybys. Real time data return became possible through dramatic increase in the communications bandwidth at only modest sacrifice in the quality of the returned pictures. Two identical long focal length cameras (1500 mm) were selected and it will be possible to return several thousand pictures from both planets at resolutions ranging from equivalent to Earthbased to tenths of a kilometer at encounter. Systematic high resolution ultraviolet photography of Venus is planned after encounter in an attempt to understand the nature of the mysterious ultraviolet markings and their apparent 4- to 5-day rotation period. Full disk coverage in mosaics will produce pictures of both planets similar in quality to Earthbased telescopic pictures of the Moon. The increase of resolution, more than three orders of magnitude, will yield an exciting first look at two planets whose closeup appearance is unknown. ?? 1971.

LANDSAT-2 and LANDSAT-3 Flight evaluation report

NASA Technical Reports Server (NTRS)

Winchester, T. W.

1978-01-01

Flight performance analysis of LANDSAT 2 and LANDSAT 3 are presented for the period July 1978 to October 1978. Spacecraft operations and orbital parameters are summarized for each spacecraft. Data are provided on the performance and operation of the following subsystems onboard the spacecraft: power; attitude control; command/clock; telemetry; orbit adjust; magnetic moment compensating assembly; unified S band/premodulation processor; electrical interface; thermal narrowband tape recorders; wideband telemetry; attitude measurement sensor; wideband video tape recorders; return beam vidicon; multispectral scanner subsystem; and data collections.

Resonance Energy Transfer between Carbon Monoxide and Oxygen Molecules Using Dye Laser Intracavity Absorption Spectroscopy.

DTIC Science & Technology

1987-10-21

intensity changes. Greater sensitivity over single-pass measurements make this technique for observing absorption spectra more desireable. The absorber...resulting in a resolution (A) of about 0.037 A. The signal was focused onto an array of 500 detector elements in the vidicon. Because the width of each... detector is only 0.001 inch, there is a "cross talk" effect 5 between adjacent elements which lowers the resolution to about 0.074 A. Under this

Radiation effects on science instruments in Grand Tour type missions

NASA Technical Reports Server (NTRS)

Parker, R. H.

1972-01-01

The extent of the radiation effects problem is delineated, along with the status of protective designs for 15 representative science instruments. Designs for protecting science instruments from radiation damage is discussed for the various instruments to be employed in the Grand Tour type missions. A literature search effort was undertaken to collect science instrument components damage/interference effects data on the various sensitive components such as Si detectors, vidicon tubes, etc. A small experimental effort is underway to provide verification of the radiation effects predictions.

Amazonas project: Application of remote sensing techniques for the integrated survey of natural resources in Amazonas. [Brazil

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator)

1981-01-01

The use of LANDSAT multispectral scanner and return beam vidicon imagery for surveying the natural resources of the Brazilian Amazonas is described. Purposes of the Amazonas development project are summarized. The application of LANDSAT imagery to identification of vegetation coverage and soil use, identification of soil types, geomorphology, and geology and highway planning is discussed. An evaluation of the worth of LANDSAT imagery in mapping the region is presented. Maps generated by the project are included.

Quantitative analysis of drainage obtained from aerial photographs and RBV/LANDSAT images

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Formaggio, A. R.; Epiphanio, J. C. N.; Filho, M. V.

1981-01-01

Data obtained from aerial photographs (1:60,000) and LANDSAT return beam vidicon imagery (1:100,000) concerning drainage density, drainage texture, hydrography density, and the average length of channels were compared. Statistical analysis shows that significant differences exist in data from the two sources. The highly drained area lost more information than the less drained area. In addition, it was observed that the loss of information about the number of rivers was higher than that about the length of the channels.

Remote sensing: Physical principles, sensors and products, and the LANDSAT

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Steffen, C. A.; Lorenzzetti, J. A.; Stech, J. L.; Desouza, R. C. M.

1981-01-01

Techniques of data acquisition by remote sensing are introduced in this teaching aid. The properties of the elements involved (radiant energy, topograph, atmospheric attenuation, surfaces, and sensors) are covered. Radiometers, photography, scanners, and radar are described as well as their products. Aspects of the LANDSAT system examined include the characteristics of the satellite and its orbit, the multispectral band scanner, and the return beam vidicon. Pixels (picture elements), pattern registration, and the characteristics, reception, and processing of LANDSAT imagery are also considered.

Research study on stellar X-ray imaging experiment, volume 1

NASA Technical Reports Server (NTRS)

Wilson, H. H.; Vanspeybroeck, L. P.

1972-01-01

The use of microchannel plates as focal plane readout devices and the evaluation of mirrors for X-ray telescopes applied to stellar X-ray imaging is discussed. The microchannel plate outputs were either imaged on a phosphor screen which was viewed by a low light level vidicon or on a wire array which was read out by digitally processing the output of a charge division network attached to the wires. A service life test which was conducted on two image intensifiers is described.

Circular zig-zag scan video format

DOEpatents

Peterson, C.G.; Simmons, C.M.

1992-06-09

A circular, ziz-zag scan for use with vidicon tubes is disclosed. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal. 10 figs.

Spectroscopic observations of comets

NASA Technical Reports Server (NTRS)

1982-01-01

Development of a spectrograph using a microchannel plate intensifier for observing faint comets is described. The spectrograph is capable of obtaining useful spectra of objects as faint as M(2) = 18. The increased guiding efficiency achieved by the optical coupling of the ISIT vidicon of the 154 cm telescope has resulted in a better signal to noise ratio. The ability to take a direct image of the comet aids in the interpretation of the spatial profile of the emissions. Spectra of comets Schwassmann-Wachmann 1, Bradfield, Encke, Tuttle, and Stephen-Oterma are discussed.

Removal of instrument signature from Mariner 9 television images of Mars

NASA Technical Reports Server (NTRS)

Green, W. B.; Jepsen, P. L.; Kreznar, J. E.; Ruiz, R. M.; Schwartz, A. A.; Seidman, J. B.

1975-01-01

The Mariner 9 spacecraft was inserted into orbit around Mars in November 1971. The two vidicon camera systems returned over 7300 digital images during orbital operations. The high volume of returned data and the scientific objectives of the Television Experiment made development of automated digital techniques for the removal of camera system-induced distortions from each returned image necessary. This paper describes the algorithms used to remove geometric and photometric distortions from the returned imagery. Enhancement processing of the final photographic products is also described.

Landsat-1 and Landsat-2 evaluation report, 23 January 1975 to 23 April 1975

NASA Technical Reports Server (NTRS)

1975-01-01

A description of the work accomplished with the Landsat-1 and Landsat-2 satellites during the period 23 Jan. - 23 Apr. 1975 was presented. The following information was given for each satellite: operational summary, orbital parameters, power subsystem, attitude control subsystem, command/clock subsystem, telemetry subsystem, orbit adjust subsystem, magnetic moment compensating assembly, unified S-band/premodulation processor, electrical interface subsystem, thermal subsystem, narrowband tape recorders, wideband telemetry subsystem, attitude measurement sensor, wideband video tape recorders, return beam vidicon, multispectral scanner subsystem, and data collection subsystem.

A pyroelectric thermal imaging system for use in medical diagnosis.

PubMed

Black, C M; Clark, R P; Darton, K; Goff, M R; Norman, T D; Spikes, H A

1990-07-01

The value of infra-red thermography in a number of pathologies, notably rheumatology and vascular diseases, is becoming well established. However, the high cost of thermal scanners and the associated image processing computers has been a limitation to the widespread availability of this technique to the clinical community. This paper describes a relatively inexpensive thermographic system based on a pyroelectric vidicon scanner and a microcomputer. Software has been written with particular reference to the use of thermography in rheumatoid arthritis and vasospastic conditions such as Raynaud's phenomenon.

On-board multispectral classification study

NASA Technical Reports Server (NTRS)

Ewalt, D.

1979-01-01

The factors relating to onboard multispectral classification were investigated. The functions implemented in ground-based processing systems for current Earth observation sensors were reviewed. The Multispectral Scanner, Thematic Mapper, Return Beam Vidicon, and Heat Capacity Mapper were studied. The concept of classification was reviewed and extended from the ground-based image processing functions to an onboard system capable of multispectral classification. Eight different onboard configurations, each with varying amounts of ground-spacecraft interaction, were evaluated. Each configuration was evaluated in terms of turnaround time, onboard processing and storage requirements, geometric and classification accuracy, onboard complexity, and ancillary data required from the ground.

A multi-channel coronal spectrophotometer.

NASA Technical Reports Server (NTRS)

Landman, D. A.; Orrall, F. Q.; Zane, R.

1973-01-01

We describe a new multi-channel coronal spectrophotometer system, presently being installed at Mees Solar Observatory, Mount Haleakala, Maui. The apparatus is designed to record and interpret intensities from many sections of the visible and near-visible spectral regions simultaneously, with relatively high spatial and temporal resolution. The detector, a thermoelectrically cooled silicon vidicon camera tube, has its central target area divided into a rectangular array of about 100,000 pixels and is read out in a slow-scan (about 2 sec/frame) mode. Instrument functioning is entirely under PDP 11/45 computer control, and interfacing is via the CAMAC system.

Electrically actuatable temporal tristimulus-color device

DOEpatents

Koehler, Dale R.

1992-01-01

The electrically actuated light filter operates in a cyclical temporal mode to effect a tristimulus-color light analyzer. Construction is based on a Fabry-Perot interferometer comprised of a high-speed movable mirror pair and cyclically powered electrical actuators. When combined with a single vidicon tube or a monochrome solid state image sensor, a temporally operated tristimulus-color video camera is effected. A color-generated is accomplished when constructed with a companion light source and is a flicker-free colored-light source for transmission type display systems. Advantages of low cost and small physical size result from photolithographic batch-processing manufacturability.

Rocket instrument for far-UV spectrophotometry of faint astronomical objects.

PubMed

Hartig, G F; Fastie, W G; Davidsen, A F

1980-03-01

A sensitive sounding rocket instrument for moderate (~10-A) resolution far-UV (lambda1160-lambda1750-A) spectrophotometry of faint astronomical objects has been developed. The instrument employs a photon-counting microchannel plate imaging detector and a concave grating spectrograph behind a 40-cm Dall-Kirkham telescope. A unique remote-control pointing system, incorporating an SIT vidicon aspect camera, two star trackers, and a tone-encoded command telemetry link, permits the telescope to be oriented to within 5 arc sec of any target for which suitable guide stars can be found. The design, construction, calibration, and flight performance of the instrument are discussed.

Weather satellite picture receiving stations, APT digital scan converter

NASA Technical Reports Server (NTRS)

Vermillion, C. H.; Kamowski, J. C.

1975-01-01

The automatic picture transmission digital scan converter is used at ground stations to convert signals received from scanning radiometers to data compatible with ground equipment designed to receive signals from vidicons aboard operational meteorological satellites. Information necessary to understand the circuit theory, functional operation, general construction and calibration of the converter is provided. Brief and detailed descriptions of each of the individual circuits are included, accompanied by a schematic diagram contained at the end of each circuit description. Listings of integral parts and testing equipment required as well as an overall wiring diagram are included. This unit will enable the user to readily accept and process weather photographs from the operational meteorological satellites.

Holocamera for 3-D micrography of the alert human eye

NASA Astrophysics Data System (ADS)

Tokuda, A. R.; Auth, D. C.; Bruckner, A. P.

1980-07-01

A holocamera that safely records holograms of the full depth of the alert human eye with a spatial resolution of about 20 microns is described. A single-mode argon-ion laser generating 2 W at 5145 A serves as the illuminating source. Holographic exposure times of 0.3 msec are achieved by means of a fail-safe electromechanical shutter system. Integrated retinal irradiance levels are well under the American National Standards Institute safety standards. Reconstructed real images are projected directly onto the vidicon faceplate of a closed-circuit TV system, enabling convenient scanning in the x-y-z dimensions of the reconstructed eyeball. Serially reconstructed holograms of cataractous rabbit eyes and normal human eyes are presented.

Images of the future - Two decades in astronomy

NASA Technical Reports Server (NTRS)

Weistrop, D.

1982-01-01

Future instruments for the 100-10,000 A UV-wavelength region will require detectors with greater quantum efficiency, smaller picture elements, a greater wavelength range, and greater active area than those currently available. After assessing the development status and performance characteristics of vidicons, image tubes, electronographic cameras, digicons, silicon arrays and microchannel plate intensifiers presently employed by astronomical spacecraft, attention is given to such next-generation detectors as the Mosaicked Optical Self-scanned Array Imaging Camera, which consists of a photocathode deposited on the input side of a microchannel plate intensifier. The problems posed by the signal processing and data analysis requirements of the devices foreseen for the 21st century are noted.

LANDSAT-1 and LANDSAT-2 flight evaluation report

NASA Technical Reports Server (NTRS)

1976-01-01

The LANDSAT-1 spacecraft was launched from the Western Test Range on 23 July 1972, at 18:08:06.508Z. The launch and orbital injection phase of the space flight was nominal and deployment of the spacecraft followed predictions. Orbital operations of the spacecraft and payload subsystems were satisfactory through Orbit 147, after which an internal short circuit disabled one of the Wideband Video Tape Recorders (WBVTR-2). Operations resumed until Orbit 196, when the Return Beam Vidicon failed to respond when commanded off. The RBV was commanded off via alternate commands. LANDSAT-1 continued to perform its imaging mission with the Multispectral Scanner and the remaining Wideband Video Tape Recorder providing image data.

Development of television tubes for the large space telescope

NASA Technical Reports Server (NTRS)

Lowrance, J. L.; Zucchino, P.

1971-01-01

Princeton Observatory has been working for several years under NASA sponsorship to develop television type sensors to use in place of photographic film for space astronomy. The performance of an SEC-vidicon with a 25 mm x 25 mm active area, MgF2 window, and bi-alkali photocathode is discussed. Results from ground based use on the Coude spectrograph of the 200-inch Hale telescope are included. The intended use of this tube in an echelle spectrograph sounding rocket payload and on Stratoscope 2 for direct high resolution imagery is also discussed. The paper also discusses the large space telescope image sensor requirements and the development of a larger television tube for this mission.

Manual on characteristics of Landsat computer-compatible tapes produced by the EROS Data Center digital image processing system

USGS Publications Warehouse

Holkenbrink, Patrick F.

1978-01-01

Landsat data are received by National Aeronautics and Space Administration (NASA) tracking stations and converted into digital form on high-density tapes (HDTs) by the Image Processing Facility (IPF) at the Goddard Space Flight Center (GSFC), Greenbelt, Maryland. The HDTs are shipped to the EROS Data Center (EDC) where they are converted into customer products by the EROS Data Center digital image processing system (EDIPS). This document describes in detail one of these products: the computer-compatible tape (CCT) produced from Landsat-1, -2, and -3 multispectral scanner (MSS) data and Landsat-3 only return-beam vidicon (RBV) data. Landsat-1 and -2 RBV data will not be processed by IPF/EDIPS to CCT format.

Eighth year projects and activities of the Environmental Remote Sensing Applications Laboratory (ERSAL). [Oregon

NASA Technical Reports Server (NTRS)

Lewis, A. J.; Isaacson, D. L.; Schrumpf, B. J. (Principal Investigator)

1980-01-01

Projects completed for the NASA Office of University Affairs include the application of remote sensing data in support of rehabilitation of wild fire damaged areas and the use of LANDSAT 3 return beam vidicon in forestry mapping applications. Continuing projects for that office include monitoring western Oregon timber clearcut; detecting and monitoring wheat disease; land use monitoring for tax assessment in Umatilla, Lake, and Morrow Counties; and the use of Oregon Air National Guard thermal infrared scanning data. Projects funded through other agencies include the remote sensing inventory of elk in the Blue Mountains; the estimation of burned agricultural acreage in the Willamette Valley; a resource inventory of Deschutes County; and hosting a LANDSAT digital workshop.

Solar corona/prominence seen through the White Light Coronograph

NASA Technical Reports Server (NTRS)

1974-01-01

The solar corona and a solar prominence as seen through the White Light Coronograph, Skylab Experiment S052, on January 17, 1974. This view was reproduced from a television transmission made by a TV camera aboard the Skylab space station in Earth orbit. The bright spot is a burn in the vidicon. The solar corona is the halo around the Sun which is normally visible only at the time of solar eclipse by the Moon. The Skylab coronography uses an externally-mounted disk system which occults the brilliant solar surface while allowing the fainter radiation of the corona to enter an annulus and be photographed. A mirror system allows either TV viewing of the corona or photographic recording of the image.

Exploration of Mars by Mariner 9 - Television sensors and image processing.

NASA Technical Reports Server (NTRS)

Cutts, J. A.

1973-01-01

Two cameras equipped with selenium sulfur slow scan vidicons were used in the orbital reconnaissance of Mars by the U.S. Spacecraft Mariner 9 and the performance characteristics of these devices are presented. Digital image processing techniques have been widely applied in the analysis of images of Mars and its satellites. Photometric and geometric distortion corrections, image detail enhancement and transformation to standard map projection have been routinely employed. More specializing applications included picture differencing, limb profiling, solar lighting corrections, noise removal, line plots and computer mosaics. Information on enhancements as well as important picture geometric information was stored in a master library. Display of the library data in graphic or numerical form was accomplished by a data management computer program.

Improved LANDSAT to give better view of earth resources

NASA Technical Reports Server (NTRS)

1978-01-01

The launch data of LANDSAT 3 is announced. The improved capability of the spacecrafts' remote sensors (the return beam vidicon and the multispectral scanner) and application of LANDSAT data to the study of energy supplies, food production, and global large-scale environmental monitoring are discussed along with the piggyback amateur radio communication satellite-OSCAR-D, the plasma Interaction Experiment, and the data collection system onboard LANDSAT 3. An assessment of the utility of LANDSAT multispectral data is given based on the research results to data from studies of LANDSAT 1 and 2 data. Areas studied include agriculture, rangelands, forestry, water resources, environmental and marine resources, environmental and marine resources, cartography, land use, demography, and geological surveys and mineral/petroleum exploration.

Computer quantitation of coronary angiograms

NASA Technical Reports Server (NTRS)

Ledbetter, D. C.; Selzer, R. H.; Gordon, R. M.; Blankenhorn, D. H.; Sanmarco, M. E.

1978-01-01

A computer technique is being developed at the Jet Propulsion Laboratory to automate the measurement of coronary stenosis. A Vanguard 35mm film transport is optically coupled to a Spatial Data System vidicon/digitizer which in turn is controlled by a DEC PDP 11/55 computer. Programs have been developed to track the edges of the arterial shadow, to locate normal and atherosclerotic vessel sections and to measure percent stenosis. Multiple frame analysis techniques are being investigated that involve on the one hand, averaging stenosis measurements from adjacent frames, and on the other hand, averaging adjacent frame images directly and then measuring stenosis from the averaged image. For the latter case, geometric transformations are used to force registration of vessel images whose spatial orientation changes.

An evaluation of the first four LANDSAT-D thematic mapper reflective sensors for monitoring vegetation: A comparison with other satellite sensor systems

NASA Technical Reports Server (NTRS)

Tucker, C. J.

1978-01-01

The first four LANDSAT-D thematic mapper sensors were evaluated and compared to: the return beam vidicon (RBV) and multispectral scanners (MSS) sensors from LANDSATS 1, 2, and 3; Colvocoresses' proposed 'operational LANDSAT' three band system; and the French SPOT three band system using simulation/intergration techniques and in situ collected spectral reflectance data. Sensors were evaluated by their ability to discriminate vegetation biomass, chlorophyll concentration, and leaf water content. The thematic mapper and SPOT bands were found to be superior in a spectral resolution context to the other three sensor systems for vegetational applications. Significant improvements are expected for most vegetational analyses from LANDSAT-D thematic mapper and SPOT imagery over MSS and RBV imagery.

Mapping of land use and geomorphology in the APAPORE project area by LANDSAT satellite data, volume 1

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Dossantos, A. P.; Kux, H. J.; Sausen, T. M.; Bueno, A. M. T. R.; Desouza, L. F.; Nunes, J. S. D.

1982-01-01

The results of a land use and geomorphological mapping of the so-called Projeto APAPORE area, at Mato Grosso do Sul State are presented. The study was carried out using multispectral scanner (MSS) and return beam vidicon LANDSAT images (channels 5 and 7 for the MSS) at the scale of 1:250,000 from 1980 through visual interpretation. The results indicate that pastureland is the most widespead class and that the agricultural areas re concentrated in the north of the area under study. The area covered with cerradao (arboreous savanna type) has a great areal extention, thus permitting the advance of the agricultural frontier. The geomorphological mapping can be useful to regional planning of future land use within the studied area.

Solar corona/prominence seen through the White Light Coronograph

NASA Image and Video Library

1974-01-17

S74-15697 (17 Jan. 1974) --- The solar corona and a solar prominence as seen through the White Light Coronograph, Skylab Experiment S052, on Jan. 17, 1974. This view was reproduced from a television transmission made by a TV camera aboard the Skylab space station in Earth orbit. The bright spot is a burn in the vidicon. The solar corona is the halo around the sun which is normally visible only at the time of solar eclipse by the moon. The Skylab coronography uses an externally-mounted disk system which occults the brilliant solar surface while allowing the fainter radiation of the corona to enter an annulus and be photographed. A mirror system allows either TV viewing of the corona or photographic recording of the image. Photo credit: NASA

The information systems heritage. [overview of technology developments over past five decades

NASA Technical Reports Server (NTRS)

Kurzhals, P. R.; Bricker, R. W.; Jensen, A. S.; Smith, A. T.

1981-01-01

This paper addresses key developments in the evolution of information systems over the past five decades. Major areas covered include the growth of imaging sensors from such pioneering devices as the iconoscope and orthicon which ushered in television, through a wide range of vidicon tubes, to the solid-state arrays which characterize current systems; the phenomenal expansion of electronic communications from telegraph and telephone wires, through the introduction of broadcast and microwave relay services, to the present era of worldwide satellite communications and data networks; and the key role of digital computers from their ancient precursors like the abacus and the mechanical calculating engines, through the appearance of the first large-scale electronic computers and their transistorized successors, to the rapid proliferation of miniaturized processors which impact every aspect of aerospace systems today.

Advanced Sensors and Applications Study (ASAS)

NASA Technical Reports Server (NTRS)

Chism, S. B.; Hughes, C. L.

1976-01-01

The present EOD requirements for sensors in the space shuttle era are reported with emphasis on those applications which were deemed important enough to warrant separate sections. The application areas developed are: (1) agriculture; (2) atmospheric corrections; (3) cartography; (4) coastal studies; (5) forestry; (6) geology; (7) hydrology; (8) land use; (9) oceanography; and (10) soil moisture. For each application area. The following aspects were covered: (1) specific goals and techniques, (2) individual sensor requirements including types, bands, resolution, etc.; (3) definition of mission requirements, type orbits, coverages, etc.; and (4) discussion of anticipated problem areas and solutions. The remote sensors required for these application areas include; (1) camera systems; (2) multispectral scanners; (3) microwave scatterometers; (4) synthetic aperture radars; (5) microwave radiometers; and (6) vidicons. The emphasis in the remote sensor area was on the evaluation of present technology implications about future systems.

Radiation studies of optical and electronic components used in astronomical satellite studies

NASA Technical Reports Server (NTRS)

Becher, J.; Kernell, R. L.

1981-01-01

The synchronous orbit of the IUE carries the satellite through Earth's outer electron belt. A 40 mCi Sr90 source was used to simulate these electrons. A 5 mCi source of Co60 was used to simulate bremmstrahlung. A 10 MeV electron Linac and a 1.7 MeV electron Van de Graaf wer used to investigate the energy dependence of radiation effects and to perform radiations at a high flux rate. A 100 MeV proton cyclotron was used to simulate cosmic rays. Results are presented for three instrument systems of the IUE and measurements for specific components are reported. The three instrument systems were the ultraviolet converter, the fine error sensor (FES), and the SEC vidicon camera tube. The components were optical glasses, electronic components, silicon photodiodes, and UV window materials.

The 1984 eclipse of the symbiotic binary SY Muscae

NASA Technical Reports Server (NTRS)

Kenyon, S. J.; Michalitisianos, A. G.; Lutz, J. H.; Kafatos, M.

1985-01-01

Data from IUE spectra obtained with the 10 x 20-arcsec aperture on May 13, 1984, and optical spectrophotometry obtained with an SIT vidicon on the 1.5-m telescope at CTIO on April 29-May 1, 1984, are reported for the symbiotic binary SY Mus. The data are found to be consistent with a model of a red-giant secondary of 60 solar radii which completely eclipses the hot primary every 627 d but only partially eclipses the 75-solar-radius He(+) region surrounding the primary. The distance to SY Mus is estimated as 1.3 kpc. It is suggested that the large Balmer decrement in eclipse, with (H-alpha)/(H-beta) = 8.3 and (H-beta)/(H-gamma) = 1.5, is associated with an electron density of about 10 to the 10th/cu cm.

Multispectral mapping of the lunar surface using groundbased telescopes

NASA Technical Reports Server (NTRS)

Mccord, T. B.; Pieters, C.; Feirberg, M. A.

1976-01-01

Images of the lunar surface were obtained at several wavelengths using a silicon vidicon imaging system and groundbased telescopes. These images were recorded and processed in digital form so that quantitative information is preserved. The photometric precision of the images is shown to be better than 1 percent. Ratio images calculated by dividing images obtained at two wavelengths (0.40/0.56 micrometer) and 0.95/0.56 micrometer are presented for about 50 percent of the lunar frontside. Spatial resolution is about 2 km at the sub-earth point. A complex of distinct units is evident in the images. Earlier work with the reflectance spectrum of lunar materials indicates that for the most part these units are compositionally distinct. Digital images of this precision are extremely useful to lunar geologists in disentangling the history of the lunar surface.

The new MSFC Solar vector magnetograph. Center director's discretionary fund

NASA Technical Reports Server (NTRS)

Hagyard, M. J.; West, E. A.; Cumings, N. P.

1984-01-01

The unique MSFC solar vector magnetograph allows measurements of all three components of the Sun's photospheric magnetic field over a wide field-of-view with spatial resolution determined by a 2.7 x 2.7 arc second pixel size. This system underwent extensive modifications to improve its sensitivity and temporal response. The modifications included replacing an SEC vidicon detector with a solid-state CCD camera; replacing the original digital logic circuitry with an electronic controller and a computer to provide complete, programmable control over the entire operation of the magnetograph; and installing a new polarimeter which consists of a single electro-optical modulator coupled with interchangeable waveplates mounted on a rotating assembly. The system is described and results of calibrations and tests are presented. Initial observations of solar magnetic fields with the new magnetograph are presented.

Spectral reflectance measurements of plant soil combinations

NASA Technical Reports Server (NTRS)

Macleod, N. H.

1972-01-01

Field and laboratory observations of plant and soil reflectance spectra were made to develop an understanding of the reflectance of solar energy by plants and soils. A related objective is the isolation of factors contributing to the image formed by multispectral scanners and return beam vidicons carried by ERTS or film-filter combinations used in the field or on aircraft. A set of objective criteria are to be developed for identifying plant and soil types and their changing condition through the seasons for application of space imagery to resource management. This is because the global scale of earth observations satellites requires objective rather than subjective techniques, particularly where ground truth is either not available or too costly to acquire. As the acquiring of ground truth for training sets may be impractical in many cases, attempts have been made to identify objectively standard responses which could be used for image interpretation.

The exploration of outer space with cameras: A history of the NASA unmanned spacecraft missions

NASA Astrophysics Data System (ADS)

Mirabito, M. M.

The use of television cameras and other video imaging devices to explore the solar system's planetary bodies with unmanned spacecraft is chronicled. Attention is given to the missions and the imaging devices, beginning with the Ranger 7 moon mission, which featured the first successfully operated electrooptical subsystem, six television cameras with vidicon image sensors. NASA established a network of parabolic, ground-based antennas on the earth (the Deep Space Network) to receive signals from spacecraft travelling farther than 16,000 km into space. The image processing and enhancement techniques used to convert spacecraft data transmissions into black and white and color photographs are described, together with the technological requirements that drove the development of the various systems. Terrestrial applications of the planetary imaging systems are explored, including medical and educational uses. Finally, the implementation and functional characteristics of CCDs are detailed, noting their installation on the Space Telescope.

ERTS computer compatible tape data processing and analysis. Appendix 1: The utility of imaging radars for the study of lake ice

NASA Technical Reports Server (NTRS)

Polcyn, F. C.; Thomson, F. J.; Porcello, L. J.; Sattinger, I. J.; Malila, W. A.; Wezernak, C. T.; Horvath, R.; Vincent, R. K. (Principal Investigator); Bryan, M. L.

1972-01-01

There are no author-identified significant results in this report. Remotely sensed multispectral scanner and return beam vidicon imagery from ERTS-1 is being used for: (1) water depth measurements in the Virgin Islands and Upper Lake Michigan areas; (2) mapping of the Yellowstone National Park; (3) assessment of atmospheric effects in Colorado; (4) lake ice surveillance in Canada and Great Lakes areas; (5) recreational land use in Southeast Michigan; (6) International Field Year on the Great Lakes investigations of Lake Ontario; (7) image enhancement of multispectral scanner data using existing techniques; (8) water quality monitoring of the New York Bight, Tampa Bay, Lake Michigan, Santa Barbara Channel, and Lake Erie; (9) oil pollution detection in the Chesapeake Bay, Gulf of Mexico southwest of New Orleans, and Santa Barbara Channel; and (10) mapping iron compounds in the Wind River Mountains.

Evaluation of SIR-A (Shuttle Imaging Radar) images from the Tres Marias region (Minas Gerais State, Brazil) using derived spatial features and registration with MSS-LANDSAT images

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Kux, H. J. H.; Dutra, L. V.

1984-01-01

Two image processing experiments are described using a MSS-LANDSAT scene from the Tres Marias region and a shuttle Imaging Radar SIR-A image digitized by a vidicon scanner. In the first experiment the study area is analyzed using the original and preprocessed SIR-A image data. The following thematic classes are obtained: (1) water, (2) dense savanna vegetation, (3) sparse savanna vegetation, (4) reforestation areas and (5) bare soil areas. In the second experiment, the SIR-A image was registered together with MSS-LANDSAT bands five, six, and seven. The same five classes mentioned above are obtained. These results are compared with those obtained using solely MSS-LANDSAT data. The spatial information as well as coregistered SIR-A and MSS-LANDSAT data can increase the separability between classes, as compared to the use of raw SIR-A data solely.

The contributions of Ranger photographs to understanding the geology of the moon

NASA Technical Reports Server (NTRS)

Trask, N. J.

1972-01-01

Vidicon photographs returned to earth by Rangers 7, 8, and 9 in 1964 and 1965 were used to study the details of lunar geologic units previously recognized from earth-based telescopic photographs and to make geologic maps at a variety of scales. The photographs from each mission changed continuously in scale as the spacecraft approached impact. The final frames had resolutions some 1,000 times better than the best earthbased photographs. Lunar stratigraphic units mapped at a scale of 1:1,000,000 displayed, at these larger scales, differences in properties and, possibly, in ages, but a clear-cut stratigraphic succession of subunits was not apparent. The plains-forming materials in both terra and mare were divisible into units mainly on the basis of the differences in the total number of superposed craters and in the relative number of craters of various morphologic types.

EOS mapping accuracy study

NASA Technical Reports Server (NTRS)

Forrest, R. B.; Eppes, T. A.; Ouellette, R. J.

1973-01-01

Studies were performed to evaluate various image positioning methods for possible use in the earth observatory satellite (EOS) program and other earth resource imaging satellite programs. The primary goal is the generation of geometrically corrected and registered images, positioned with respect to the earth's surface. The EOS sensors which were considered were the thematic mapper, the return beam vidicon camera, and the high resolution pointable imager. The image positioning methods evaluated consisted of various combinations of satellite data and ground control points. It was concluded that EOS attitude control system design must be considered as a part of the image positioning problem for EOS, along with image sensor design and ground image processing system design. Study results show that, with suitable efficiency for ground control point selection and matching activities during data processing, extensive reliance should be placed on use of ground control points for positioning the images obtained from EOS and similar programs.

Lightweight helmet-mounted eye movement measurement system

NASA Technical Reports Server (NTRS)

Barnes, J. A.

1978-01-01

The helmet-mounted eye movement measuring system, weighs 1,530 grams; the weight of the present aviators' helmet in standard form with the visor is 1,545 grams. The optical head is standard NAC Eye-Mark. This optical head was mounted on a magnesium yoke which in turn was attached to a slide cam mounted on the flight helmet. The slide cam allows one to adjust the eye-to-optics system distance quite easily and to secure it so that the system will remain in calibration. The design of the yoke and slide cam is such that the subject can, in an emergency, move the optical head forward and upward to the stowed and locked position atop the helmet. This feature was necessary for flight safety. The television camera that is used in the system is a solid state General Electric TN-2000 with a charged induced device imager used as the vidicon.

A Normal Incidence X-ray Telescope (NIXT) sounding rocket payload

NASA Technical Reports Server (NTRS)

Golub, Leon

1989-01-01

Work on the High Resolution X-ray (HRX) Detector Program is described. In the laboratory and flight programs, multiple copies of a general purpose set of electronics which control the camera, signal processing and data acquisition, were constructed. A typical system consists of a phosphor convertor, image intensifier, a fiber optics coupler, a charge coupled device (CCD) readout, and a set of camera, signal processing and memory electronics. An initial rocket detector prototype camera was tested in flight and performed perfectly. An advanced prototype detector system was incorporated on another rocket flight, in which a high resolution heterojunction vidicon tube was used as the readout device for the H(alpha) telescope. The camera electronics for this tube were built in-house and included in the flight electronics. Performance of this detector system was 100 percent satisfactory. The laboratory X-ray system for operation on the ground is also described.

A computer controlled television detector for light, X-rays and particles

NASA Technical Reports Server (NTRS)

Kalata, K.

1981-01-01

A versatile, high resolution, software configurable, two-dimensional intensified vidicon quantum detector system has been developed for multiple research applications. A thin phosphor convertor allows the detection of X-rays below 20 keV and non-relativistic particles in addition to visible light, and a thicker scintillator can be used to detect X-rays up to 100 keV and relativistic particles. Faceplates may be changed to allow any active area from 1 to 40 mm square, and active areas up to 200 mm square are possible. The image is integrated in a digital memory on any software specified array size up to 4000 x 4000. The array size is selected to match the spatial resolution, which ranges from 10 to 100 microns depending on the operating mode, the active area, and the photon or particle energy. All scan and data acquisition parameters are under software control to allow optimal data collection for each application.

Online aptitude automatic surface quality inspection system for hot rolled strips steel

NASA Astrophysics Data System (ADS)

Lin, Jin; Xie, Zhi-jiang; Wang, Xue; Sun, Nan-Nan

2005-12-01

Defects on the surface of hot rolled steel strips are main factors to evaluate quality of steel strips, an improved image recognition algorithm are used to extract the feature of Defects on the surface of steel strips. Base on the Machine vision and Artificial Neural Networks, establish a defect recognition method to select defect on the surface of steel strips. Base on these research. A surface inspection system and advanced algorithms for image processing to hot rolled strips is developed. Preparing two different fashion to lighting, adopting line blast vidicon of CCD on the surface steel strips on-line. Opening up capacity-diagnose-system with level the surface of steel strips on line, toward the above and undersurface of steel strips with ferric oxide, injure, stamp etc of defects on the surface to analyze and estimate. Miscarriage of justice and alternate of justice rate not preponderate over 5%.Geting hold of applications on some big enterprises of steel at home. Experiment proved that this measure is feasible and effective.

Detection of turbidity dynamics in Tampa Bay, Florida using multispectral imagery from ERTS-1

NASA Technical Reports Server (NTRS)

Coker, A. E.; Higer, A. L.; Goodwin, C. R.

1973-01-01

In 1970, Congress authorized the deepening of the Tampa Bay channel (Rivers and Harbors Act of 1970) from 34 to 44 feet. In order to determine the effects of this deepening on circulation, water quality, and biota, during and after the construction, the U.S. Geological Survey, in cooperation with the Tampa Port Authority, has collected data and developed a digital simulation model of the bay. In addition to data collected using conventional tools, use is being made of data collected from ERTS-1. Return beam vidicon (RBV) multispectral data were collected, while a shell dredging barge was operating in the bay, and used for turbidity recognition and unique spectral signatures representative of type and amount of material in suspension. A three-dimensional concept of the dynamics of the plume was achieved by superimposing the parts of the plume recognized in each RBV band. This provides a background for automatic computer processing of ERTS data and three-dimensional modeling of turbidity plumes.

Statis omnidirectional stereoscopic display system

NASA Astrophysics Data System (ADS)

Barton, George G.; Feldman, Sidney; Beckstead, Jeffrey A.

1999-11-01

A unique three camera stereoscopic omnidirectional viewing system based on the periscopic panoramic camera described in the 11/98 SPIE proceedings (AM13). The 3 panoramic cameras are equilaterally combined so each leg of the triangle approximates the human inter-ocular spacing allowing each panoramic camera to view 240 degree(s) of the panoramic scene, the most counter clockwise 120 degree(s) being the left eye field and the other 120 degree(s) segment being the right eye field. Field definition may be by green/red filtration or time discrimination of the video signal. In the first instance a 2 color spectacle is used in viewing the display or in the 2nd instance LCD goggles are used to differentiate the R/L fields. Radially scanned vidicons or re-mapped CCDs may be used. The display consists of three vertically stacked 120 degree(s) segments of the panoramic field of view with 2 fields/frame. Field A being the left eye display and Field B the right eye display.

LANDSAT 3 return beam vidicon response artifacts: A report on RBV photographic product characteristics and quality coding system

NASA Technical Reports Server (NTRS)

Clark, B. P.

1981-01-01

Analysis of large volumes of LANDSAT 3 RBV digital data that were converted to photographic form led to the firm identification of several visible artifacts (objects or structures not normally present, but producted by an external agency or action) in the imagery. These artifacts were identified, categorized, and traced directly to specific sensor response characteristics. None of these artifacts is easily removed and all cases remain under active study of possible future enhancement. The seven generic categories of sensor response artifacts identified to date include: (1) shading and stairsteps; (2) corners out of focus; (3) missing reseaus; (4) reseau distortion and data distortion; (5) black vertical line; (6) grain effect; and (7) faceplate contamination. An additional category under study, but not yet determined to be caused by sensor response, is a geometric anomaly. Examples of affected imagery are presented to assist in distinguishing between image content and innate defects caused by the sensor system.

Radiation tolerant compact image sensor using CdTe photodiode and field emitter array (Conference Presentation)

NASA Astrophysics Data System (ADS)

Masuzawa, Tomoaki; Neo, Yoichiro; Mimura, Hidenori; Okamoto, Tamotsu; Nagao, Masayoshi; Akiyoshi, Masafumi; Sato, Nobuhiro; Takagi, Ikuji; Tsuji, Hiroshi; Gotoh, Yasuhito

2016-10-01

A growing demand on incident detection is recognized since the Great East Japan Earthquake and successive accidents in Fukushima nuclear power plant in 2011. Radiation tolerant image sensors are powerful tools to collect crucial information at initial stages of such incidents. However, semiconductor based image sensors such as CMOS and CCD have limited tolerance to radiation exposure. Image sensors used in nuclear facilities are conventional vacuum tubes using thermal cathodes, which have large size and high power consumption. In this study, we propose a compact image sensor composed of a CdTe-based photodiode and a matrix-driven Spindt-type electron beam source called field emitter array (FEA). A basic principle of FEA-based image sensors is similar to conventional Vidicon type camera tubes, but its electron source is replaced from a thermal cathode to FEA. The use of a field emitter as an electron source should enable significant size reduction while maintaining high radiation tolerance. Current researches on radiation tolerant FEAs and development of CdTe based photoconductive films will be presented.

Design study report. Volume 2: Electronic unit

NASA Technical Reports Server (NTRS)

1973-01-01

The recording system discussed is required to record and reproduce wideband data from either of the two primary Earth Resources Technology Satellite sensors: Return Beam Vidicon (RBV) camera or Multi-Spectral Scanner (MSS). The camera input is an analog signal with a bandwidth from dc to 3.5 MHz; this signal is accommodated through FM recording techniques which provide a recorder signal-to-noise ratio in excess of 39 db, black-to-white signal/rms noise, over the specified bandwidth. The MSS provides, as initial output, 26 narrowband channels. These channels are multiplexed prior to transmission, or recording, into a single 15 Megabit/second digital data stream. Within the recorder, the 15 Megabit/second NRZL signal is processed through the same FM electronics as the RBV signal, but the basic FM standards are modified to provide an internal, 10.5 MHz baseland response with signal-to-noise ratio of about 25 db. Following FM demodulation, however, the MSS signal is digitally re-shaped and re-clocked so that good bit stability and signal-to-noise exist at the recorder output.

Multisensor analysis of hydrologic features with emphasis on the Seasat SAR

NASA Technical Reports Server (NTRS)

Foster, J. L.; Hall, D. K.

1981-01-01

Synthetic aperture radar (SAR) imagery of the Wind River Range area in Wyoming is compared with visible and near-infrared imagery of the same area. Data from the Seasat L-Band SAR and an aircraft X-Band SAR are compared with Landsat Return Beam Vidicon (RBV) visible data and near-infrared aerial photography and topographic maps of the same area. It is noted that visible and near-infrared data provide more information than the SAR data when conditions are the most favorable. The SAR penetrates clouds and snow, however, and data can be acquired day or night. Drainage density detail is good on SAR imagery because individual streams show up well owing to riparian vegetation; this causes higher radar reflections which result from the 'rough' surface which vegetation creates. In the winter image, the X-Band radar data show high returns because of cracks on the lake ice surfaces. High returns can also be seen in the L-Band SAR imagery of the lakes due to ripples on the surface induced by wind. It is concluded that the use of multispectral data would optimize analysis of hydrologic features.

Test and Evaluation of the Surveyor 3 Television Camera Returned from the Moon by Apollo 12. Volume 1

NASA Technical Reports Server (NTRS)

1970-01-01

Results are presented of engineering tests of the Surveyor III television camera, which resided on the moon for 2 and 1/2 years before being brought back to earth by the Apollo XII astronauts. Electric circuits, electrical, mechanical, and optical components and subsystems, the vidicon tube, and a variety of internal materials and surface coatings were examined to determine the effects of lunar exposure. Anomalies and failures uncovered were analyzed. For the most part, the camera parts withstood the extreme environment exceedingly well except where degradation of obsolete parts or suspect components had been anticipated. No significant evidence of cold welding was observed, and the anomalies were largely attributable to causes other than lunar exposure. Very little evidence of micrometeoroid impact was noted. Discoloration of material surfaces -- one of the major effects noted--was found to be due to lunar dust contamination and radiation damage. The extensive test data contained in this report are supplemented by results of tests of other Surveyor parts retrieved by the Apollo XII astronauts, which are contained in a companion report.

A real-time electronic imaging system for solar X-ray observations from sounding rockets

NASA Technical Reports Server (NTRS)

Davis, J. M.; Ting, J. W.; Gerassimenko, M.

1979-01-01

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.

The Solid State Image Sensor's Contribution To The Development Of Silicon Technology

NASA Astrophysics Data System (ADS)

Weckler, Gene P.

1985-12-01

Until recently, a solid-state image sensor with full television resolution was a dream. However, the dream of a solid state image sensor has been a driving force in the development of silicon technology for more than twenty-five years. There are probably many in the main stream of semiconductor technology who would argue with this; however, the solid state image sensor was conceived years before the invention of the semi conductor RAM or the microprocessor (i.e., even before the invention of the integrated circuit). No other potential application envisioned at that time required such complexity. How could anyone have ever hoped in 1960 to make a semi conductor chip containing half-a-million picture elements, capable of resolving eight to twelve bits of infornation, and each capable of readout rates in the tens of mega-pixels per second? As early as 1960 arrays of p-n junctions were being investigated as the optical targets in vidicon tubes, replacing the photoconductive targets. It took silicon technology several years to catch up with these dreamers.

Laser Scanning In Inspection

NASA Astrophysics Data System (ADS)

West, Patricia; Baker, Lionel R.

1989-03-01

This paper is a review of the applications of laser scanning in inspection. The reasons for the choice of a laser in flying spot scanning and the optical properties of a laser beam which are of value in a scanning instrument will be given. The many methods of scanning laser beams in both one and two dimensions will be described. The use of one dimensional laser scanners for automatic surface inspection for transmitting and reflective products will be covered in detail, with particular emphasis on light collection techniques. On-line inspection applications which will be mentioned include: photographic film web, metal strip products, paper web, glass sheet, car body paint surfaces and internal cylinder bores. Two dimensional laser scanning is employed in applications where increased resolution, increased depth of focus, and better contrast are required compared with conventional vidicon TV or solid state array cameras. Such examples as special microscope laser scanning systems and a TV compatible system for use in restricted areas of a nuclear reactor will be described. The technical and economic benefits and limitations of laser scanning video systems will be compared with conventional TV and CCD array devices.

Chemistry of cometary meteoroids from video-tape records of meteor spectra

NASA Technical Reports Server (NTRS)

Millman, P. M.

1982-01-01

The chemistry of the cometary meteoroids was studied by closed circuit television observing systems. Vidicon cameras produce basic data on standard video tape and enable the recording of the spectra of faint shower meteors, consequently the chemical study is extended to smaller particles and we have a larger data bank than is available from the more conventional method of recording meteor spectra by photography. The two main problems in using video tape meteor spectrum records are: (1) the video tape recording has a much lower resolution than the photographic technique; (2) video tape is relatively new type of data storage in astronomy and the methods of quantitative photometry have not yet been fully developed in the various fields where video tape is used. The use of the most detailed photographic meteor spectra to calibrate the video tape records and to make positive identification of the more prominent chemical elements appearing in the spectra may solve the low resolution problem. Progress in the development of standard photometric techniques for the analysis of video tape records of meteor spectra is reported.

ERTS operations and data processing

NASA Technical Reports Server (NTRS)

Gonzales, L.; Sos, J. Y.

1974-01-01

The overall communications and data flow between the ERTS spacecraft and the ground stations and processing centers are generally described. Data from the multispectral scanner and the return beam vidicon are telemetered to a primary ground station where they are demodulated, processed, and recorded. The tapes are then transferred to the NASA Data Processing Facility (NDPF) at Goddard. Housekeeping data are relayed from the prime ground stations to the Operations Control Center at Goddard. Tracking data are processed at the ground stations, and the calculated parameters are transmitted by teletype to the orbit determination group at Goddard. The ERTS orbit has been designed so that the same swaths of the ground coverage pattern viewed during one 18-day coverage cycle are repeated by the swaths viewed on all subsequent cycles. The Operations Control Center is the focal point for all communications with the spacecraft. NDPF is a job-oriented facility which processes and stores all sensor data, and which disseminates large quantities of these data to users in the form of films, computer-compatible tapes, and data collection system data.

Velocity dispersions in galaxies: 1: The SO galaxy NGC 7332

NASA Technical Reports Server (NTRS)

Morton, D. C.; Chevalier, R. A.

1971-01-01

A Coude spectrum of the SO galaxy NGC 7332 with 0.9 A resolution from 4186 to 4364 A was obtained with the SEC vidicon television camera and the Hale telescope. Comparisons with spectra of G and K giant stars, numerically broadened for various Maxwellian velocity distributions, give a dispersion velocity in the line of sight of 160 + or - 20 km/sec with the best fit at G8III. The dispersion appears to be constant within + or - 35 km/sec out to 1.4 kpc (H = 100 km/sec/mpc). After correction for projection, the rotation curve has a slope of 0.16 km/sec/pc at the center and a velocity of 130 km/sec at 1.4 kpc where it is still increasing. For an estimated effective radius of 3.5 kpc enclosing half the light, the virial theorem gives a mass of 1.4 x 10 to the 11th power solar masses if the mass-to-light ratio is constant throughout the galaxy. The photographic luminosity is 8.3 x 10 to the 9th power solar luminosities so that the M/L ratio is 17.

Measurement of insulation integrity of IUE camera tube facsimiles by partial discharges method and diffusion of gases through various silicone rubbers

NASA Technical Reports Server (NTRS)

Bever, R. S.

1977-01-01

Several dummy tubes imitating the IUE Camera System design were encapsulated with Solithane 2, Conathane EN-11, Green and Black Hysols and SMRD 432. Various flaws were purposefully placed in some of these. Partial discharge testing in vacuum under direct voltage conditions was carried once a week for 12 weeks, 15 kv dc being applied during normal working hours for 40 hours duration per week. None of the units showed much damage during this time judging by the P.D. energy histograms. A more complete mathematical presentation is given on diffusion and permeation than previously. Measurements of diffusion constants for various silicone rubbers are carried out by the Time-Lag method and compared to other determinations in the literature. Calculations of the time required for diffusion through a thick wall are demonstrated in the long time approximation and for dimensions pertaining to void and wall sizes of a delamination problem in the LANDSAT-C vidicon tubes. An actual delaminated LANDSAT-C tube and some facsimiles are immersed in vacuum for long periods and tested for catastrophic breakdown due to diffusion of gas, by application of high voltage.

Remotely sensed data available from the US Geological Survey EROS Data Center

USGS Publications Warehouse

Dwyer, John L.; Qu, J.J.; Gao, W.; Kafatos, M.; Murphy , R.E.; Salomonson, V.V.

2006-01-01

The Center for Earth Resources Observation Systems (EROS) is a field center of the geography discipline within the US geological survey (USGS) of the Department of the Interior. The EROS Data Center (EDC) was established in the early 1970s as the nation’s principal archive of remotely sensed data. Initially the EDC was responsible for the archive, reproduction, and distribution of black-and-white and color-infrared aerial photography acquired under numerous mapping programs conducted by various Federal agencies including the USGS, Department of Agriculture, Environmental Protection Agency, and NASA. The EDC was also designated the central archive for data acquired by the first satellite sensor designed for broad-scale earth observations in support of civilian agency needs for earth resource information. A four-band multispectral scanner (MSS) and a return-beam vidicon (RBV) camera were initially flown on the Earth Resources Technology Satellite-1, subsequently designated Landsat-1. The synoptic coverage, moderate spatial resolution, and multi-spectral view provided by these data stimulated scientists with an unprecedented perspective from which to study the Earth’s surface and to understand the relationships between human activity and natural systems.

Landsat real-time processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, E.L.

A novel method for performing real-time acquisition and processing Landsat/EROS data covers all aspects including radiometric and geometric corrections of multispectral scanner or return-beam vidicon inputs, image enhancement, statistical analysis, feature extraction, and classification. Radiometric transformations include bias/gain adjustment, noise suppression, calibration, scan angle compensation, and illumination compensation, including topography and atmospheric effects. Correction or compensation for geometric distortion includes sensor-related distortions, such as centering, skew, size, scan nonlinearity, radial symmetry, and tangential symmetry. Also included are object image-related distortions such as aspect angle (altitude), scale distortion (altitude), terrain relief, and earth curvature. Ephemeral corrections are also applied to compensatemore » for satellite forward movement, earth rotation, altitude variations, satellite vibration, and mirror scan velocity. Image enhancement includes high-pass, low-pass, and Laplacian mask filtering and data restoration for intermittent losses. Resource classification is provided by statistical analysis including histograms, correlational analysis, matrix manipulations, and determination of spectral responses. Feature extraction includes spatial frequency analysis, which is used in parallel discriminant functions in each array processor for rapid determination. The technique uses integrated parallel array processors that decimate the tasks concurrently under supervision of a control processor. The operator-machine interface is optimized for programming ease and graphics image windowing.« less

G301: The Flying Falcon geological remote sensing experiment

NASA Technical Reports Server (NTRS)

Vincent, Robert K.; Birnbach, Curtis; Mengel, Arthur H.

1995-01-01

Get-Away Special (GAS) G-301, named the Flying Falcon and scheduled for launch on the STS-77 Space Shuttle in April, 1996, is being prepared to perform an experiment designed by the Department of Geology, Bowling Green State University (BGSU). The experiment will employ a new type of infrared imager designed and built by a consortium of Teltron Technologies Inc., Hudson Research Inc., and BGSU that is an uncooled, quantrum ferro-electric, infrared return beam vidicon (IRBV) camera capable of detecting thermal infrared radiation throughout the 2.0-50.0 micron wavelength region, and to which an integral, unable Fabry-Perot filter and a telescopic lens have been added. The primary objectives in the experiment include the mapping of methane plumes from solid waste landfills and wetlands in the midwestern U.S., the mapping of methane plumes offshore in the Gulf of Mexico and in the Middle East, brief monitoring for precursors of volcanoes or earthquakes in the South China sea and the East Pacific Rise (about 300 km west of Easter Island), and the mapping of silica content in exposed outcrops and residual soils of the southwestern U.S. and Middle East.

A computer-aided telescope pointing system utilizing a video star tracker

NASA Technical Reports Server (NTRS)

Murphy, J. P.; Lorell, K. R.; Swift, C. D.

1975-01-01

The Video Inertial Pointing (VIP) System developed to satisfy the acquisition and pointing requirements of astronomical telescopes is described. A unique feature of the system is the use of a single sensor to provide information for the generation of three axis pointing error signals and for a cathode ray tube (CRT) display of the star field. The pointing error signals are used to update the telescope's gyro stabilization and the CRT display is used by an operator to facilitate target acquisition and to aid in manual positioning of the telescope optical axis. A model of the system using a low light level vidicon built and flown on a balloon-borne infrared telescope is briefly described from a state of the art charge coupled device (CCD) sensor. The advanced system hardware is described and an analysis of the multi-star tracking and three axis error signal generation, along with an analysis and design of the gyro update filter, are presented. Results of a hybrid simulation are described in which the advanced VIP system hardware is driven by a digital simulation of the star field/CCD sensor and an analog simulation of the telescope and gyro stabilization dynamics.

Marshall Space Flight Center's Tower Vector Magnetograph: Upgrades, Hardware, and Operations for the HESSI Mission

NASA Technical Reports Server (NTRS)

Adams, M. L.; Hagyard, M. J.; West, E. A.; Smith, J. E.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

The Marshall Space Flight Center's (MSFC) solar group announces the successful upgrade of our tower vector magnetograph. In operation since 1973, the last major alterations to the system (which includes telescope, filter, polarizing optics, camera, and data acquisition computer) were made in 1982, when we upgraded from an SEC Vidicon camera to a CCD. In 1985, other changes were made which increased the field-of-view from 5 x 5 arc min (2.4 arc sec per pixel) to 6 x 6 arc min with a resolution of 2.81 arc sec. In 1989, the Apollo Telescope Mount H-alpha telescope was coaligned with the optics of the magnetograph. The most recent upgrades (year 2000), funded to support the High Energy Solar Spectroscopic Imager (HESSI) mission, have resulted in a pixel size of 0.64 arc sec over a 7 x 5.2 arc min field-of-view (binning 1x1). This poster describes the physical characteristics of the new system and compares spatial resolution, timing, and versatility with the old system. Finally, we provide a description of our Internet web site, which includes images of our most recent observations, and links to our data archives, as well as the history of magnetography at MSFC and education outreach pages.

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics

DOEpatents

Ellingson, William A.; Brada, Mark P.

1995-01-01

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser's wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known "feature masks" of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects.

Automated mass spectrometer analysis system

NASA Technical Reports Server (NTRS)

Boettger, Heinz G. (Inventor); Giffin, Charles E. (Inventor); Dreyer, William J. (Inventor); Kuppermann, Aron (Inventor)

1978-01-01

An automated mass spectrometer analysis system is disclosed, in which samples are automatically processed in a sample processor and converted into volatilizable samples, or their characteristic volatilizable derivatives. Each volatizable sample is sequentially volatilized and analyzed in a double focusing mass spectrometer, whose output is in the form of separate ion beams all of which are simultaneously focused in a focal plane. Each ion beam is indicative of a different sample component or different fragments of one or more sample components and the beam intensity is related to the relative abundance of the sample component. The system includes an electro-optical ion detector which automatically and simultaneously converts the ion beams, first into electron beams which in turn produce a related image which is transferred to the target of a vidicon unit. The latter converts the images into electrical signals which are supplied to a data processor, whose output is a list of the components of the analyzed sample and their abundances. The system is under the control of a master control unit, which in addition to monitoring and controlling various power sources, controls the automatic operation of the system under expected and some unexpected conditions and further protects various critical parts of the system from damage due to particularly abnormal conditions.

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics

DOEpatents

Ellingson, W.A.; Brada, M.P.

1995-06-20

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser`s wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known ``feature masks`` of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects. 29 figs.

Electro-optical detector for use in a wide mass range mass spectrometer

NASA Technical Reports Server (NTRS)

Giffin, Charles E. (Inventor)

1976-01-01

An electro-optical detector is disclosed for use in a wide mass range mass spectrometer (MS), in the latter the focal plane is at or very near the exit end of the magnetic analyzer, so that a strong magnetic field of the order of 1000G or more is present at the focal plane location. The novel detector includes a microchannel electron multiplier array (MCA) which is positioned at the focal plane to convert ion beams which are focused by the MS at the focal plane into corresponding electron beams which are then accelerated to form visual images on a conductive phosphored surface. These visual images are then converted into images on the target of a vidicon camera or the like for electronic processing. Due to the strong magnetic field at the focal plane, in one embodiment of the invention, the MCA with front and back parallel ends is placed so that its front end forms an angle of not less than several degrees, preferably on the order of 10.degree.-20.degree., with respect to the focal plane, with the center line of the front end preferably located in the focal plane. In another embodiment the MCA is wedge-shaped, with its back end at an angle of about 10.degree.-20.degree. with respect to the front end. In this embodiment the MCA is placed so that its front end is located at the focal plane.

Satellite Image Atlas of Glaciers of the World

USGS Publications Warehouse

Williams, Richard S.; Ferrigno, Jane G.

2005-01-01

In 1978, the USGS began the preparation of the 11-chapter USGS Professional Paper 1386, 'Satellite Image Atlas of Glaciers of the World'. Between 1979 and 1981, optimum satellite images were distributed to a team of 70 scientists, representing 25 nations and 45 institutions, who agreed to author sections of the Professional Paper concerning either a geographic area (chapters B-K) or a glaciological topic (included in Chapter A). The scientists used Landsat 1, 2, and 3 multispectral scanner (MSS) images and Landsat 2 and 3 return beam vidicon (RBV) images to inventory the areal occurrence of glacier ice on our planet within the boundaries of the spacecrafts' coverage (between about 82? north and south latitudes). Some later contributors also used Landsat 4 and 5 MSS and Thematic Mapper, Landsat 7 Enhanced Thematic Mapper-Plus (ETM+), and other satellite images. In addition to analyzing images of a specific geographic area, each author was asked to summarize up-to-date information about the glaciers within each area and compare their present-day areal distribution with reliable historical information (from published maps, reports, and photographs) about their past extent. Because of the limitations of Landsat images for delineating or monitoring small glaciers in some geographic areas (the result of inadequate spatial resolution, lack of suitable seasonal coverage, or absence of coverage), some information on the areal distribution of small glaciers was derived from ancillary sources, including other satellite images. Completion of the atlas will provide an accurate regional inventory of the areal extent of glaciers on our planet during a relatively narrow time interval (1972-1981).

Mert Davies: Pioneer in the Use of Spacecraft to Map Earth and Mars

NASA Astrophysics Data System (ADS)

Murray, B.; Augenstein, B.

2002-12-01

Mert Davies was one of the founding employees of the RAND Corporation in 1946, and continued that relationship until his death in 2001. He began his involvement in satellite imaging at Rand as one of about 100 researchers in Project Feedback in 1954, provided the basis for the initial US military space program. In 1957, in response to the Soviet launch of Sputnik, Mert and a small group of Rand cohorts proposed a family of recoverable reconnaissance satellites featuring spin stabilized cameras, for which he later received a patent. This work, now declassified, was for a short time considered as a basis for the Corona, America's first reconnaissance satellite Corona, although ultimately alternative technologies were employed. In addition he was looking beyond Earth quite early and in May, 1958 published an analysis of a lunar mapping satellite. The 1957 work at Rand spurred considerations of space-based geodesy and mapping. These and other early contributions were recognized in 1999 by the National Reconnaissance Office which honored him as one of the founders of national reconnaissance. He was so enthused by the opportunity developing in the mid 1960?s to explore photographically the planets that he changed careers and joined the Television Team of the Mariner probes being developed to flyby Mars in 1969 (Mariner's 6&7). His abilities and accomplishments there led directly to central roles later in the Mariner 9 Mars Orbiter mission (1971-72) as well as Mariner 10 to Mercury (1973-75) and Voyagers 1&2 (1979-89) These early flights to Mars represented unprecedented technical challenges, especially to radio communications. As a consequence, analog television systems, like that carried on the Ranger impact probe in 1964-65 or film readout technology like that used on Lunar Orbiter in 1965-66 to send back high-resolution images from the Moon were not feasible from planetary distances. In order to exploit the remarkable communication potential of the DSN, JPL-based television teams invented the world?s first digital television cameras using primitive slow-scan vidicon sensors in order to overcome the 200-fold greater distance to Mars. Spacecraft mapping and geodesy was initiated by the dual flybys Mariner 6 and 7 of 1969, each carrying a moderately high resolution optical system, but one plagued by the geometric limitations of a vidicon sensor necessarily using imprecise electro-optical imaging internally. He understood clearly that the number of resolution elements on the Mariner 6/7 cameras were too small for good photogrammetric solutions. Each picture contained only 70,000 resolution elements compared to a standard aerial photograph with about a third of a billion of comparable elements. Despite such limitations, Mert was able to exploit especially the far encounter imaging from Mariners 6/7 to create the first Mars surface control net based on topographic features, and to solve for the position of the rotational pole. Under his leadership, the Mariner 9 orbiter mission greatly expanded that coverage, providing the evolving basis of USGS Mars mapping practically until the present. Furthermore, Mert, in conjunction with Harold Masursky and Gerard de Vaucoleurs, established the topocentric reference point for the prime meridian on Mars as the small crater Airy-O, which thus occupies a role analogous to that of Greenwich, England for the Earth. He was to play that historic prime meridian role for nearly all the solid bodies in the Solar System over the ensuing decades as well as a continuing role on the IAU committee that named officially the surface features of Mercury, Venus, Mars, and the satellites of Jupiter, Saturn, Uranus.

ARC-1990-AC79-7127

NASA Image and Video Library

1990-02-14

Range : 4 billion miles from Earth, at 32 degrees to the ecliptic. P-36057C This color image of the Sun, Earth, and Venus is one of the first, and maybe, only images that show are solar system from such a vantage point. The image is a portion of a wide angle image containing the sun and the region of space where the Earth and Venus were at the time, with narrow angle cameras centered on each planet. The wide angle was taken with the cameras darkest filter, a methane absorption band, and the shortest possible exposure, one two-hundredth of a second, to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large in the sky, as seen from Voyager's perpective at the edge of the solar system. Yet, it is still 8xs brighter than the brightest star in Earth's sky, Sirius. The image of the sun you see is far larger than the actual dimension of the solar disk. The result of the brightness is a bright burned out image with multiple reflections from the optics of the camera. The rays around th sun are a diffraction pattern of the calibration lamp which is mounted in front of the wide angle lens. the 2 narrow angle frames containing the images of the Earth and Venus have been digitally mosaicked into the wide angle image at the appropriate scale. These images were taken through three color filters and recombined to produce the color image. The violet, green, and blue filters used , as well as exposure times of .72,.48, and .72 for Earth, and .36, .24, and .36 for Venus.The images also show long linear streaks resulting from scatering of sulight off parts of the camera and its shade.

Global color variations on the Martian surface

USGS Publications Warehouse

Soderblom, L.A.; Edwards, K.; Eliason, E.M.; Sanchez, E.M.; Charette, M.P.

1978-01-01

Surface materials exposed throughout the equatorial region of Mars have been classified and mapped on the basis of spectral reflectance properties determined by the Viking II Orbiter vidicon cameras. Frames acquired at each of three wavelengths (0.45 ?? 0.03 ??m, 0.53 ?? 0.05 ??m, and 0.59 ?? 0.05 ??m) during the approach of Viking Orbiter II in Martian summer (Ls = 105??) were mosaicked by computer. The mosaics cover latitudes 30??N to 63??S for 360?? of longitude and have resolutions between 10 and 20 km per line pair. Image processing included Mercator transformation and removal of an average Martian photometric function to produce albedo maps at three wavelengths. The classical dark region between the equator and ???30??S in the Martian highlands is composed of two units: (i) and ancient unit consisting of topographic highs (ridges, crater rims, and rugged plateaus riddled with small dendritic channels) which is among the reddest on the planet (0.59/0.45 ??m {reversed tilde equals} 3); and (ii) intermediate age, smooth, intercrater volcanic plains displaying numerous mare ridges which are among the least red on Mars (0.59/0.45 ??m {reversed tilde equals} 2). The relatively young shield volcanoes are, like the oldest unit, dark and very red. Two probable eolian deposits are recognized in the intermediate and high albedo regions. The stratigraphically lower unit is intermediate in both color (0.59/ 0.45 ??m {reversed tilde equals} 2.5) and albedo. The upper unit has the highest albedo, is very red (0.59/0.45 ??m {reversed tilde equals} 3), and is apparently the major constituent of the annual dust storms as its areal extent changes from year to year. The south polar ice cap and condensate clouds dominate the southernmost part of the mosaics. ?? 1978.

Flying high-altitude balloon-borne telescopes 50 years ago

NASA Astrophysics Data System (ADS)

Fazio, Giovanni G.

Based on theoretical predictions of cosmic gamma-ray fluxes by P. Morrison (1958) and M. Savedoff (1959), we started, at the University of Rochester, a program in high-energy gammaray astronomy to search for these sources using high-altitude balloon-borne telescopes. The first flight occurred in 1959 from Sioux Falls, SD, using scintillator/Cerenkov detectors. In 1962 I initiated a gamma-ray astronomy program at the Smithsonian Astrophysical Observatory (SAO) using vidicon spark chambers. Later Henry Helmken (SAO) developed a program in low-energy gamma-ray astronomy based on a gas Cerenkov detector. During the 1960's more flights followed from San Angelo, TX; Holloman AFB, NM; Hyderabad, India, and finally, Palestine, TX. All of these flights just produced upper limits to the cosmic gamma-ray flux. We also entered a collaboration with the Cornell Group (K. Greisen) to fly a large gas-Cerenkov telescope to search for ˜ 100 MeV gamma-rays. In the early 1970's, using this telescope, gammarays from the Crab Nebula pulsar were detected (McBreen et al. 1973). It soon became evident that gamma-ray astronomy, to be successful, had to be performed from space telescopes. In 1970, somewhat frustrated, I changed fields and started at SAO/Harvard the construction of a 1-meter balloon-borne telescope for far-infrared astronomy. This was a collaborative program with the University of Arizona (F. Low). This program was extremely successful, resulting in 19 flights over 20 years, and produced the first far-infrared high-resolution maps of many new galactic regions and detection of solar system sources. Experience gained from these programs later led to the development and flight of space gamma-ray and infrared telescopes and many of the participants were, and some still are, active in numerous space programs.

A television scanner for the ultracentrifuge. II. Multiple cell operation.

PubMed

Rockholt, D L; Royce, C R; Richards, E G

1976-07-01

The "Optical Multichannel Analyzer" (OMA) is a commercially available instrument that with the absorption optical system of the ultracentrifuge, provides an entire 500 channel intensity profile of a cell in real time. With its own analog-todigital converter, the OMA integrates a selectable number of 32.8 msec scans to provide a time-averaged image in digital form. This paper describes an interface-controller for operation of the OMA with single- and double-sector cells in multi-cell rotors, simulating double-beam measurement required for absorbance determinations. The desired sector is selected by "gating" the intensifier stage of a "Silicon Intensified Target" vidicon (SIT) used as the light detector. The cell location in the rotor and the position of the gate relative to the cell centerline is obtained from a phase-locked loop circuit which divides each rotation of the rotor into 3600 parts independent of rotor speed. (This circuit employed with photo-multiplier scanners would select the gate position for integration of photomultiplier pulses.) From examination of appropriate signals with an oscilloscope, it was verified that gate positions and widths are located with an accuracy of 0.1degree or better and with a precision of +/- 0.1 mus. The light intensity profile for any desired cell can be examined in "real time", even during acceleration of the rotor. Additional circuits employing a 10 MHz crystal clock 1) control the automatic collection of data for all sectors in multicell rotors at digitally selected time intervals, 2) display the rotor speed, and 3) indicate the elapsed time of the experiment. Constructed but not tested are additional circuits for pulsing a laser into the absorption or Rayleigh optical system. The accuracy of the pulsed SIT has been demonstrated by measurement of absorbances of solutions and also by sedimentation equilibrium experiments with myoglobin. The estimated error is 0.003 for absorbances ranging from 0 to 1. The interface-controller operates extremely well, but problems related to the pulsed SIT (optimum gate position relative to the sector opening shape of high-voltage pulse, slight pincushion distortion) require more work.

The cool-star spectral catalog: A uniform collection of IUE SWP-LOs

NASA Technical Reports Server (NTRS)

Ayres, T.; Lenz, D.; Burton, R.; Bennett, J.

1992-01-01

Over the past decade and a half of its operations, the International Ultraviolet Explorer has recorded low-dispersion spectrograms in the 1150-2000 A interval of more than 800 stars of late spectral type (F-M). The sub-2000 A region contains a number of emission lines that are key diagnostics of physical conditions in the high-excitation chromospheres and subcoronal 'transition zones' of such stars. Many of the sources have been observed a number of times, and the available collection of SWP-LO exposures in the IUE Archives exceeds 4,000. With support from the Astrophysics Data Program, we have assembled the archival material into a catalog of IUE far-UV fluxes of late-type stars. In order to ensure uniform processing of the spectra, we: (1) photometrically corrected the raw vidicon images with a custom version of the 1985 SWP ITF; (2) identified and eliminated, sharp cosmic-ray 'hits' by means of a spatial filter; (3) extracted the spectral traces with the 'optimal' (weighted-slit) strategy; and (4) calibrated them against a well-characterized reference source, the DA white dwarf G191-B2B. Our approach is similar to that adopted by the IUE Project for its 'Final Archive', but our implementation is specialized to the case of chromospheric emission-line sources. We measured the resulting SWP-LO spectra using a semi-autonomous algorithm that establishes a smooth continuum by numerical filtering, and then fits the significant emissions (or absorptions) by means of a constrained Bevington-type multiple-Gaussian procedure. The algorithm assigns errors to the fitted fluxes - or upper limits in the absence of a significant detection - according to a model based on careful measurements of the noise properties of the IUE's intensified SEC cameras. Here, we describe the 'visualization' strategies we adopted to ensure human-review of the semi-autonomous processing and measuring algorithms; the derivation of the noise model and the assignment of errors; and the structure of the final catalog as delivered to the Astrophysics Data System.

PRISM: A Practical Mealtime Imaging Stereo Matcher

NASA Astrophysics Data System (ADS)

Nishihara, H. K.

1984-02-01

A fast stereo-matching algorithm designed to operate in the presence of noise is described. The algorithm has its roots in the zero-crossing theory of Marr and Poggio but does not explicitly match zero-crossing contours. While these contours are for the most part stably tied to fixed surface locations, some fraction is always perturbed significantly by system noise. Zero-crossing contour based matching algorithms tend to I- very sensitive to these local distortions and ar, prevented from operating well on signals with moderate noise levels even though a substantial amount of information may still be present. The dual representation ¬â€?regions of constant sign in the V2G convolution persist much further into the noise than does the local geometry of the zero-crossing contours that delimit them. The PRISM system was designed to test this approach. The initial design task of the implementation has been to rapidly detect obstacles in a robotics work space and determine their rough extents and heights. In this case speed and reliability are important but precision is less critical. The system uses a pair of inexpensive vidicon cameras mounted above the workspace of a PUMA robot manipulator. The digitized video signals are fed to a high speed digital convolver that applies a 322 VG operator to the images at a 106 pixel per second rate. Matching is accomplished in software on a lisp machine with individual near/far tests taking less than i3luth of a second. A 36 by 26 matrix of absolute height measurements - in mm - over a 100 pixel disparity range is produced in 30 seconds from image acquisition to final output. Three scales of resolution are used in a coarse guides fine search. Acknowledgment: This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of 'Technology Support for the laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-80-C-0505 and in part by National Science Foundation Grant 79-23110MCS.

Solar System Portrait - 60 Frame Mosaic

NASA Image and Video Library

1996-09-13

The cameras of Voyager 1 on Feb. 14, 1990, pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever portrait of our solar system as seen from the outside. In the course of taking this mosaic consisting of a total of 60 frames, Voyager 1 made several images of the inner solar system from a distance of approximately 4 billion miles and about 32 degrees above the ecliptic plane. Thirty-nine wide angle frames link together six of the planets of our solar system in this mosaic. Outermost Neptune is 30 times further from the sun than Earth. Our sun is seen as the bright object in the center of the circle of frames. The wide-angle image of the sun was taken with the camera's darkest filter (a methane absorption band) and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large as seen from Voyager, only about one-fortieth of the diameter as seen from Earth, but is still almost 8 million times brighter than the brightest star in Earth's sky, Sirius. The result of this great brightness is an image with multiple reflections from the optics in the camera. Wide-angle images surrounding the sun also show many artifacts attributable to scattered light in the optics. These were taken through the clear filter with one second exposures. The insets show the planets magnified many times. Narrow-angle images of Earth, Venus, Jupiter, Saturn, Uranus and Neptune were acquired as the spacecraft built the wide-angle mosaic. Jupiter is larger than a narrow-angle pixel and is clearly resolved, as is Saturn with its rings. Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposures. From Voyager's great distance Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. http://photojournal.jpl.nasa.gov/catalog/PIA00451

Consistency of L4 TM absolute calibration with respect to the L5 TM sensor based on near-simultaneous image acquisition

NASA Astrophysics Data System (ADS)

Chander, Gyanesh; Helder, Dennis L.; Malla, Rimy; Micijevic, Esad; Mettler, Cory J.

2007-09-01

The Landsat archive provides more than 35 years of uninterrupted multispectral remotely sensed data of Earth observations. Since 1972, Landsat missions have carried different types of sensors, from the Return Beam Vidicon (RBV) camera to the Enhanced Thematic Mapper Plus (ETM+). However, the Thematic Mapper (TM) sensors on Landsat 4 (L4) and Landsat 5 (L5), launched in 1982 and 1984 respectively, are the backbone of an extensive archive. Effective April 2, 2007, the radiometric calibration of L5 TM data processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) was updated to use an improved lifetime gain model, based on the instrument's detector response to pseudo-invariant desert site data and cross-calibration with the L7 ETM+. However, no modifications were ever made to the radiometric calibration procedure of the Landsat 4 (L4) TM data. The L4 TM radiometric calibration procedure has continued to use the Internal Calibrator (IC) based calibration algorithms and the post calibration dynamic ranges, as previously defined. To evaluate the "current" absolute accuracy of these two sensors, image pairs from the L5 TM and L4 TM sensors were compared. The number of coincident image pairs in the USGS EROS archive is limited, so the scene selection for the cross-calibration studies proved to be a challenge. Additionally, because of the lack of near-simultaneous images available over well-characterized and traditionally used calibration sites, alternate sites that have high reflectance, large dynamic range, high spatial uniformity, high sun elevation, and minimal cloud cover were investigated. The alternate sites were identified in Yuma, Iraq, Egypt, Libya, and Algeria. The cross-calibration approach involved comparing image statistics derived from large common areas observed eight days apart by the two sensors. This paper summarizes the average percent differences in reflectance estimates obtained between the two sensors. The work presented in this paper is a first step in understanding the current performance of L4 TM absolute calibration and potentially serves as a platform to revise and improve the radiometric calibration procedures implemented for the processing of L4 TM data.

Consistency of L4 TM absolute calibration with respect to the L5 TM sensor based on near-simultaneous image acquisition

USGS Publications Warehouse

Chander, G.; Helder, D.L.; Malla, R.; Micijevic, E.; Mettler, C.J.

2007-01-01

The Landsat archive provides more than 35 years of uninterrupted multispectral remotely sensed data of Earth observations. Since 1972, Landsat missions have carried different types of sensors, from the Return Beam Vidicon (RBV) camera to the Enhanced Thematic Mapper Plus (ETM+). However, the Thematic Mapper (TM) sensors on Landsat 4 (L4) and Landsat 5 (L5), launched in 1982 and 1984 respectively, are the backbone of an extensive archive. Effective April 2, 2007, the radiometric calibration of L5 TM data processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) was updated to use an improved lifetime gain model, based on the instrument's detector response to pseudo-invariant desert site data and cross-calibration with the L7 ETM+. However, no modifications were ever made to the radiometric calibration procedure of the Landsat 4 (L4) TM data. The L4 TM radiometric calibration procedure has continued to use the Internal Calibrator (IC) based calibration algorithms and the post calibration dynamic ranges, as previously defined. To evaluate the "current" absolute accuracy of these two sensors, image pairs from the L5 TM and L4 TM sensors were compared. The number of coincident image pairs in the USGS EROS archive is limited, so the scene selection for the cross-calibration studies proved to be a challenge. Additionally, because of the lack of near-simultaneous images available over well-characterized and traditionally used calibration sites, alternate sites that have high reflectance, large dynamic range, high spatial uniformity, high sun elevation, and minimal cloud cover were investigated. The alternate sites were identified in Yuma, Iraq, Egypt, Libya, and Algeria. The cross-calibration approach involved comparing image statistics derived from large common areas observed eight days apart by the two sensors. This paper summarizes the average percent differences in reflectance estimates obtained between the two sensors. The work presented in this paper is a first step in understanding the current performance of L4 TM absolute calibration and potentially serves as a platform to revise and improve the radiometric calibration procedures implemented for the processing of L4 TM data.

Solar System Portrait - 60 Frame Mosaic

NASA Technical Reports Server (NTRS)

1990-01-01

The cameras of Voyager 1 on Feb. 14, 1990, pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever 'portrait' of our solar system as seen from the outside. In the course of taking this mosaic consisting of a total of 60 frames, Voyager 1 made several images of the inner solar system from a distance of approximately 4 billion miles and about 32 degrees above the ecliptic plane. Thirty-nine wide angle frames link together six of the planets of our solar system in this mosaic. Outermost Neptune is 30 times further from the sun than Earth. Our sun is seen as the bright object in the center of the circle of frames. The wide-angle image of the sun was taken with the camera's darkest filter (a methane absorption band) and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large as seen from Voyager, only about one-fortieth of the diameter as seen from Earth, but is still almost 8 million times brighter than the brightest star in Earth's sky, Sirius. The result of this great brightness is an image with multiple reflections from the optics in the camera. Wide-angle images surrounding the sun also show many artifacts attributable to scattered light in the optics. These were taken through the clear filter with one second exposures. The insets show the planets magnified many times. Narrow-angle images of Earth, Venus, Jupiter, Saturn, Uranus and Neptune were acquired as the spacecraft built the wide-angle mosaic. Jupiter is larger than a narrow-angle pixel and is clearly resolved, as is Saturn with its rings. Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposures. From Voyager's great distance Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun.

Multiframe digitization of x-ray (TV) images (abstract)

NASA Astrophysics Data System (ADS)

Karpenko, V. A.; Khil'chenko, A. D.; Lysenko, A. P.; Panchenko, V. E.

1989-07-01

The work in progress deals with the experimental search for a technique of digitizing x-ray TV images. The small volume of the buffer memory of the analog-to-digital (A/D) converter (ADC) we have previously used to detect TV signals made it necessary to digitize only one line at a time of the television raster and also to make use of gating to gain the video information contained in the whole frame. This paper is devoted to multiframe digitizing. The recorder of video signals comprises a broadband 8-bit A/D converter, a buffer memory having 128K words and a control circuit which forms a necessary sequence of advance pulses for the A/D converter and the memory relative to the input frame and line sync pulses (FSP and LSP). The device provides recording of video signals corresponding to one or a few frames following one after another, or to their fragments. The control circuit is responsible for the separation of the required fragment of the TV image. When loading the limit registers, the following input parameters of the control circuit are set: the skipping of a definite number of lines after the next FSP, the number of the lines of recording inside a fragment, the frequency of the information lines inside a fragment, the delay in the start of the ADC conversion relative to the arrival of the LSP, the length of the information section of a line, and the frequency of taking the readouts in a line. In addition, among the instructions given are the number of frames of recording and the frequency of their sequence. Thus, the A/D converter operates only inside a given fragment of the TV image. The information is introduced into the memory in sequence, fragment by fragment, without skipping and is then extracted as samples according to the addresses needed for representation in the required form, and processing. The video signal recorder governs the shortest time of the ADC conversion per point of 250 ns. As before, among the apparatus used were an image vidicon with luminophor conversion of x-radiation to light, and a single-crystal x-ray diffraction scheme necessary to form dynamic test objects from x-ray lines dispersed in space (the projections of the linear focus of an x-ray tube).

Solar System Portrait - View of the Sun, Earth and Venus

NASA Image and Video Library

1996-09-13

This color image of the sun, Earth and Venus was taken by the Voyager 1 spacecraft Feb. 14, 1990, when it was approximately 32 degrees above the plane of the ecliptic and at a slant-range distance of approximately 4 billion miles. It is the first -- and may be the only -- time that we will ever see our solar system from such a vantage point. The image is a portion of a wide-angle image containing the sun and the region of space where the Earth and Venus were at the time with two narrow-angle pictures centered on each planet. The wide-angle was taken with the camera's darkest filter (a methane absorption band), and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large in the sky as seen from Voyager's perspective at the edge of the solar system but is still eight million times brighter than the brightest star in Earth's sky, Sirius. The image of the sun you see is far larger than the actual dimension of the solar disk. The result of the brightness is a bright burned out image with multiple reflections from the optics in the camera. The "rays" around the sun are a diffraction pattern of the calibration lamp which is mounted in front of the wide angle lens. The two narrow-angle frames containing the images of the Earth and Venus have been digitally mosaiced into the wide-angle image at the appropriate scale. These images were taken through three color filters and recombined to produce a color image. The violet, green and blue filters were used; exposure times were, for the Earth image, 0.72, 0.48 and 0.72 seconds, and for the Venus frame, 0.36, 0.24 and 0.36, respectively. Although the planetary pictures were taken with the narrow-angle camera (1500 mm focal length) and were not pointed directly at the sun, they show the effects of the glare from the nearby sun, in the form of long linear streaks resulting from the scattering of sunlight off parts of the camera and its sun shade. From Voyager's great distance both Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. Detailed analysis also suggests that Voyager detected the moon as well, but it is too faint to be seen without special processing. Venus was only 0.11 pixel in diameter. The faint colored structure in both planetary frames results from sunlight scattered in the optics. http://photojournal.jpl.nasa.gov/catalog/PIA00450

Solar System Portrait - View of the Sun, Earth and Venus

NASA Technical Reports Server (NTRS)

1990-01-01

This color image of the sun, Earth and Venus was taken by the Voyager 1 spacecraft Feb. 14, 1990, when it was approximately 32 degrees above the plane of the ecliptic and at a slant-range distance of approximately 4 billion miles. It is the first -- and may be the only -- time that we will ever see our solar system from such a vantage point. The image is a portion of a wide-angle image containing the sun and the region of space where the Earth and Venus were at the time with two narrow-angle pictures centered on each planet. The wide-angle was taken with the camera's darkest filter (a methane absorption band), and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large in the sky as seen from Voyager's perspective at the edge of the solar system but is still eight million times brighter than the brightest star in Earth's sky, Sirius. The image of the sun you see is far larger than the actual dimension of the solar disk. The result of the brightness is a bright burned out image with multiple reflections from the optics in the camera. The 'rays' around the sun are a diffraction pattern of the calibration lamp which is mounted in front of the wide angle lens. The two narrow-angle frames containing the images of the Earth and Venus have been digitally mosaiced into the wide-angle image at the appropriate scale. These images were taken through three color filters and recombined to produce a color image. The violet, green and blue filters were used; exposure times were, for the Earth image, 0.72, 0.48 and 0.72 seconds, and for the Venus frame, 0.36, 0.24 and 0.36, respectively. Although the planetary pictures were taken with the narrow-angle camera (1500 mm focal length) and were not pointed directly at the sun, they show the effects of the glare from the nearby sun, in the form of long linear streaks resulting from the scattering of sunlight off parts of the camera and its sun shade. From Voyager's great distance both Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. Detailed analysis also suggests that Voyager detected the moon as well, but it is too faint to be seen without special processing. Venus was only 0.11 pixel in diameter. The faint colored structure in both planetary frames results from sunlight scattered in the optics.

Stereoscopic observations from meteorological satellites

NASA Astrophysics Data System (ADS)

Hasler, A. F.; Mack, R.; Negri, A.

The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk et al. [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner et al. [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler et al. [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated. Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the two satellites. A general solution for accurate height computation depends on precise navigation of the two satellites. Validation of the geosynchronous satellite stereo using high altitude mountain lakes and vertically pointing aircraft lidar leads to a height accuracy estimate of +/- 500 m for typical clouds which have been studied. Applications of the satellite stereo include: 1) cloud top and base height measurements, 2) cloud-wind height assignment, 3) vertical motion estimates for convective clouds (Mack et al. [13], [14]), 4) temperature vs. height measurements when stereo is used together with infrared observations and 5) cloud emissivity measurements when stereo, infrared and temperature sounding are used together (see Szejwach et al. [15]). When true satellite stereo image pairs are not available, synthetic stereo may be generated. The combination of multispectral satellite data using computer produced stereo image pairs is a dramatic example of synthetic stereoscopic display. The classic case uses the combination of infrared and visible data as first demonstrated by Pichel et al. [16]. Hasler et at. [17], Mosher and Young [18] and Lorenz [19], have expanded this concept to display many channels of data from various radiometers as well as real and simulated data fields. A future system of stereoscopic satellites would be comprised of both low orbiters (as suggested by Lorenz and Schmidt [20], [19]) and a global system of geosynchronous satellites. The low earth orbiters would provide stereo coverage day and night and include the poles. An optimum global system of stereoscopic geosynchronous satellites would require international standarization of scan rate and direction, and scan times (synchronization) and resolution of at least 1 km in all imaging channels. A stereoscopic satellite system as suggested here would make an extremely important contribution to the understanding and prediction of the atmosphere.

Obituary: Jesse Greenstein, 1909-2002

NASA Astrophysics Data System (ADS)

Gunn, James Edward

2003-12-01

On the 21 October 2002, with the death of Jesse Greenstein, many of us in astronomy lost a beloved adopted father and astronomy lost one of its most influential leaders of the postwar era. Truly a giant is gone; it is easy to say that they don't make the likes of Greenstein, Spitzer, and Scharwarzschild any more, but it is unfortunately only the truth. The field has changed and grown enormously in the more than 50 years spanned by Jesse's career with no small part of this traceable directly to his efforts. His growth was shaped very much by world events. He enjoyed a quite comfortable childhood; he was born on 15 October 1909 to successful immigrant parents, Maurice and Leah, who indulged his early interests in astronomy, radio, and science in general; these interests were to remain with him the rest of his life. As a boy he thought physics dull and chemistry exciting, though later he was to be influential in the transformation of astronomy into astrophysics in this country. He was something of a prodigy, entering the Horace Mann School for boys (an excellent private high school) at age 11 and Harvard at age 16 (in 1926). He met and became close friends with Cecilia Payne, with whom he shared cultural and scientific passions. She was certainly the greatest female astronomer of the era but largely shunned and ignored by her colleagues. Thus began a curious ambivalence in his relationship with women in the field; in fact and in action he was highly supportive but much less so in word. He graduated with a BA in astronomy in October 1929, on the eve of the stock market crash. He stayed for one more year and obtained a Master's degree, prevented by ill health from a planned one-year visit to Oxford. His family had always assumed that he would forego his interest in research and take his place in the family's successful business and real estate endeavors and the seriousness of the market collapse impelled him, very much against his will, to do just that. He proved himself to be a capable manager, able to deal with difficult times and circumstances, and the family business prospered. However, his itch to be an astronomer did not falter, and in 1934, when he was convinced that the family business would survive without him, he returned to Harvard - over the objection of director Harlow Shapely who tried to persuade him that the field had advanced too far in his four-year absence for him ever to catch up! This same year he married his childhood sweetheart Naomi Kitay, whom he ever after affectionately called 'Kitty.' Naomi nourished the already-strong humanist streak in Jesse. Interested in, and passionate about, art and the theater, life in general, and whatever it was that absorbed her interest at the moment, she was a wonderful foil for Jesse's self-deprecatory and sometimes depressive moods. She died a few months before Jesse did; they had been married 66 years. At Harvard he pursued a very successful and prescient thesis on the scattering of light by interstellar grains, begun perhaps partly in an endeavor to alleviate his failure during a Master's research project to recognize the existence of dust absorption and reddening in the face of quite convincing data. His last days at Harvard were premonitory of things to come in his career. He and Fred Whipple wrote a paper attempting, quite unsuccessfully, to explain Karl Jansky's detection of strong radio emission from the center of the Galaxy as thermal emission; this was long before the existence of magnetic fields and relativistic electrons were even suspected. The problem was to wait 15 years for a solution. But Jansky's, and later Grote Reber's, observations resonated with Jesse's early interest in radio and presaged his later decisive support for radio astronomy in the U.S. In 1937 he was awarded a NRC fellowship, which he took to Yerkes Observatory. Attracted by the innovative and productive group assembled there by Otto Struve, he flourished. Still working on dust and the interstellar medium, he began a long and productive collaboration with theorist Louis Henyey. He also began his career in stellar spectroscopy at Struve's urging and did the first analysis of the peculiar hydrogen-poor object upsilon Sagittarii, thus beginning a love affair with peculiar stars and their compositions which was to last the rest of his career. During the war he and Henyey, as well as a number of other astronomers, managed to stay at Yerkes, largely putting aside astronomical research to work on the war effort. He and Henyey learned optics in the face of great difficulty (modern optical design techniques at the time being almost exclusively both proprietary and German) and produced many optical designs for the military, among which is the beautiful wide-angle, Henyey-Greenstein camera. After the war Jesse became very interested in, and supportive of, the vast changes to the field wrought by the technological developments during the war, including infrared detectors, photomultipliers, sensitive radio receivers, and rockets. Astronomy clearly stood on the threshold of a new and wonderful era, which he was determined to help usher in. The astronomical community had already recognized Jesse's genius and in 1948 he received an invitation he could not possibly refuse. He was invited to come to Caltech to build a department to do science with the soon to be completed 200-inch Hale telescope, by far the largest and most ambitious telescope project to that date. The family (there were now two sons, George and Peter) moved from the little town of Williams Bay, Wisconsin to the bustle of postwar Pasadena, California. One may well ask whether anyone, given an opportunity of this magnitude, could have failed to be great but the answer, I am certain, is that it would have been very easy indeed. It took all of Jesse's hard-won ability as a manager, his wonderful personal touch, his ease with moneyed supporters, and above all his unimpeachable scientific and personal integrity to build what is universally recognized as one of the finest departments in the world. The arcane political arrangements with the Carnegie Institution, which ran Mount Wilson and would later run both Mount Wilson and Palomar jointly with Caltech, were hammered out with Jesse's guidance before he had a chance to build the department. In the beginning the only two astronomers at Caltech were Jesse and Fritz Zwicky; Zwicky was a genius but personally incredibly difficult and Jesse was very much alone in navigating the difficult political waters. His view of the way to build the department, which time has certainly vindicated, was to hire the best international theorists he could find. He was convinced they were the smartest people being trained at that time and convinced as well that the lure of the great telescope would transform them into capable observers who would soon understand their data from an astrophysical perspective. This was wildly successful. He built a postdoctoral program around stellar abundance determinations, funded by the Air Force and aided by the many military contacts he had made during and after the war. He managed, in his tiny department, to lure the most able students in the field. The list of names among the early students and the ``graduates" of the abundance project is a who's who of astronomy: Allan Sandage, Helmut Abt, George Wallerstein, Halton Arp, Wallace Sargent, Leonard Searle, to name only a representative few. His own research continued unabated; he returned to the subject of dust with Leverett Davis and, in 1951, they proposed the magnetic alignment mechanism to explain interstellar polarization that survives essentially unchanged to the present - certainly one of the longest-lived theoretical results in the field. At Caltech's Kellogg Radiation Laboratory, there was much interest in the nuclear reactions that provide stars their energy and potentially result in observable abundance changes. This work fit hand-in-glove with Jesse's interest in stars of peculiar abundance and he forged close scientific ties with the Kellogg team, particularly Willy Fowler. Jesse arranged a controversial visit to Caltech by Fred Hoyle (Hoyle's steady state cosmology was not popular among Caltech physicists) and Hoyle's protégés Geoff and Margaret Burbidge. Their classic work with Fowler on nucleosynthesis arose from this visit. Later his research turned increasingly toward understanding the denizens of the lower left of the Hertzsprung-Russell diagram - white dwarfs, blue subdwarfs, and nuclei of planetary nebulae. He became the observational authority on such stars, and much of our current understanding of these objects is a direct outgrowth of his work. In the course of this work he obtained several spectra of faint blue objects with weak, broad emission lines that were not readily identifiable. The realization that compact stars could have very strong magnetic fields was then current, and he felt that most of these objects could be explained by peculiar Zeeman and pressure effects on the spectra of intrinsically faint degenerate objects. The quasar story has been told many times, but the realization by Maarten Schmidt in 1963 that the spectrum of 3C273 was consistent with a redshift of 16 percent led them to reassess Jesse's work on 3C48, a quasi-stellar radio source with a spectrum similar to some of the peculiar blue "stars" in his library of spectra: this turned out to be the second QSO redshift recognized, with a value of 0.37. In 1960, Jesse had obtained a spectrum of Ton 202, which he had confidently identified as a peculiar DC white dwarf 40 pc distant. When he went through his library of spectra with an eye toward new possibilities, it turned out to be a QSO with a redshift of 0.37, continuing his penchant for being right almost all the time, but with the occasional really spectacular mistake. He characterized his research and the rather frequent and profound changes of direction in a very characteristic way - he very actively wanted to skim the cream off new subjects and establish correct directions for research, but he did not care for pedantic detail. It is clear from his record that this did not mean that he was ill equipped to dig deeply; his work on dust in particular was very difficult stuff. He simply felt that he had the tools at his disposal to help at the very frontiers of astronomical research and preferred to leave the details to others. Even before he came to Caltech in 1948, Jesse was convinced by the work of Jansky and Reber, and later the British and Australians, that radio astronomy was of vast importance to the field, and he was determined that Caltech should be a center. He fought for the founding of a radio astronomy group by first gaining institutional acceptance - which was not easy - and then obtaining federal funding for the Owens Valley Radio Observatory (OVRO) in 1954 from the Office of Naval Research. In this context, it is important to note that astronomy in the U.S. had been, for a very long time, almost exclusively privately funded and the Caltech abundance project and the radio astronomy observatory were among the first large departures from this norm. Jesse's task was made even more difficult by the connection with the Carnegie Institution, which at the time had specific rules against seeking federal funds. He gradually built Caltech astronomy into the powerhouse it has been for many years. Along the way he fostered and welcomed promising new technology, beginning with photomultipliers, through radio astronomy techniques, vidicons, CCDs, and computers. His views on computers as tools for doing theory, namely that they basically trivialize theoretical research (he would not have said it ``exactly" that way) would certainly be very unpopular today. Jesse's role on the national scene was profound and controversial. He was instrumental in persuading the Navy and Air Force to fund astronomical research and he was active in the founding of the National Science Foundation; he chaired the first NSF advisory committee in astronomy. He served on countless government advisory committees and worked with other Caltech physicists in highly classified research until well after such work became highly unpopular on campuses. He pushed very hard for the founding of the national observatories, particularly NRAO. He was one of the organizers of the conference in 1954, which was explicitly aimed at convincing the government to establish NRAO - the same year he obtained funds from the Navy to build Caltech's private OVRO, which was for a long time in direct competition with the national observatory. He was also influential in the founding of the national optical observatory at Kitt Peak, though this was to be a very contentious issue later. He was chosen in 1970 to lead the second National Academy decade review of astronomy, after the ground breaking Whitford report a decade earlier. It is generally conceded that the Greenstein report was the most successful of these efforts to date in the face of a rather austere funding climate; this effort was aided by the cohesive spirit of the community, but also because of the wisdom that he brought to the enterprise. His view on the best way to conduct science was explicitly and very frankly intellectually elitist. The very best people at the very best institutions, he thought, should be supported to the fullest extent possible with money and technological support wherever it could be found. He had built the Caltech department from a gleam in George Ellery Hale's eye to one of the preeminent astronomical research institution in the world, and was proud of it. He felt that the nation owed it to science for its own sake and as a nation to support science fully. He wrote in his memoir, ``An Astronomical Life," in the "Annual Reviews of Astronomy and Astrophysics": ``Human illness and poverty cannot be cured merely by spending money, but the human condition can be ennobled by spending money wisely." He did not think that spending vast amounts of money at Kitt Peak to build giant telescopes for the whole community was the best way to spend said vast amounts of money. He felt that the elite universities had demonstrated the ability both to build big instruments (the 200-inch, the 120-inch) and to attract the astronomical staff to operate them and to do superb science with them. If the federal government were to spend the money, it should clearly go to those universities. In any event, these universities should not be allowed to wither as the national observatories grew. Curiously, his view of NRAO was very different and he personally was enthusiastic about the construction of the VLA; indeed, it was the highest-priority project of the Greenstein report. In any document such as this, one must mention offices and awards. Jesse was awarded and held most of them: the Gold Medal of the RAS, the Russell Lectureship, the Bruce Medal, the Vice Presidency of the AAS, a (controversial) chairmanship of AURA, membership in the National Academy, chairmanship of many of its, and other government, advisory committees as well as chairmanship of the decadal review. He held the first Lee DuBridge chair at Caltech. While he was appreciative of these awards, he felt that awards and honors usually came too late in a scientist's career to be useful. He was a superb scientist and skillful manager and administrator, but no description of Jesse, especially this memorial one, can possibly be complete without some attempt to describe him as a human being. It was shortly before the QSO era, in 1961, that I, as a green graduate student, first met Jesse. I was in awe, of course, but it soon became clear that there was not even a stern exterior to this remarkable man who had built the Caltech department, and who was very much a personification of American astronomy. He cared deeply about everyone in his department and clearly prided himself as an amateur psychologist. He was always available, charming, warm, and open, and eager to discuss and help with personal problems as well as scientific ones with seemingly equal willingness and enthusiasm. Naomi was called in for help with stubborn personal problems and their house on San Pasqual street was a warm, inviting place and the location of countless formal and raucous informal parties and gatherings. I never worked with him directly as a student, but felt that I knew him better than any of the faculty with whom I did work. All of the words I have read in tribute to Jesse mention him as a father; he was certainly mine, and I (and all of his many children) will miss him terribly.