Experiment msc-10, two-color earth limb photography for gemini iv
Gemini IV two-color earth limb photographic data analysis - comparative evaluation of terrestrial elevation of blue above red portion of photographed limb
GEMINI SPACECRAFT↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Two-color photoelectric photometry of the earth-shine.
Two-color photoelectric photometry of earthshine, determining earth albedos
LUNAR PHASE↗
''land'' two-color projections for viewing black and white film
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Sterkin, C. K.↗
Two-color holography
Two holograms, made simultaneously, one with a red light component and one with the harmonic UV component to give two fringes in the UV construction due to shortened wavelength. The reconstruction, obtained with a He-Ne laser, could be photographed separately, giving quality interferograms.
Heflinger, L. O.↗
Two-color photoconductive detectors
Two color sandwiched photoconductive mercury-cadmium-telluride far infrared detectors
Reynolds, J. W.↗
McCollough effect analogs of two-color projections
Bicolor projections analogs with red and green McCollough aftereffects
Stromeyer, C. F., III↗
Two-color dual-beam backscatter laser Doppler velocimeter
A laser Doppler velocimeter has been developed that uses two of the colors emitted from an argon-ion laser for the simultaneous measurement of orthogonal velocities. Designed for use in a 2.13- by 3.05-m wind tunnel, it is capable of traversing its focal volume across spatially unstable flows at scan speeds of up to 1.5 m/sec. Its optical layout and principles of operation are discussed, and the data from a typical traversal of a trailing wing-tip vortex are presented.
Grant, G. R.↗
Application of an Electro-optical Two-color Pyrometer to Measurement of Flame Temperature for Liquid Oxygen-hydrocarbon Propellant Combination
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Heidmann, M F↗
Optical data processing and projected applications of the ERTS-1 imagery covering the 1973 Mississippi River Valley floods
Flooding along the Mississippi River and some of its tributaries was imaged by the multispectral scanner (MSS) on the Earth Resources Technology Satellite (ERTS-1) on at least three orbits during the spring of 1973. The ERTS data provided the first opportunity for mapping the regional extent of flooding at the time the imagery was acquired. Special optical data processing techniques were used to produce a variety of multispectral color composites which enhanced floodplain details. One of these, a two-color composite of near infrared bands 6 and 7, was enlarged and registered to 1:250,0OO-scale topographic maps and used as the basis for preparation of flood image maps. Two specially filtered three-color composites of MSS bands 5, 6, and 7 and 4, 5, and 7 were prepared to aid in the interpretation of the data. The extent of the flooding was vividly depicted on a single image by two-color temporal composites produced on the additive-color viewer using band 7 flood data superimposed on pre-flood band 7 images. On May 24, when the floodwaters at St. Louis receded to bankfull stage, imagery was again obtained by ERTS. Analysis of temporal data composites of the pre-flood and post-flood band 7 images indicate that changes in surface reflectance characteristics caused by the flooding can be delineated, thus making it possible to map the overall area flooded without the necessity of a real-time system to track and image the peak flood waves. Regional planning and disaster relief agencies such as the Corps of Engineers, Office of Emergency Preparedness, Soil Conservation Service, interstate river basin commissions and state agencies, as well as private lending and insurance institutions, have indicated strong potential applications for ERTS image-maps of flood-prone areas.
Morris Deutsch↗
Experiments on the impact-light-flash at high velocities
Impact-light-flash at high velocities - particle acceleration and analysis - two-color temperature measurement
TEMPERATURE MEASUREMENT↗
Photometric radii of Io and Europa.
Simultaneous two-color photoelectric photometry of Io and Europa performed during their eclipse by Jupiter on the night of April 5/6, 1971, is reported and discussed. The results are compared with satellite radii obtained using other observational techniques. It is concluded that the eclipse technique can be used to infer satellite radii accurate to plus or minus 10 per cent. In principle the eclipse technique can also be applied to the satellites of Saturn, Uranus, and Neptune for early objective determinations of their radii.
Price, M. J.↗
N-Color /Hg,Cd/Te photodetectors.
N-color (Hg,Cd)Te photodetectors capable of spectral band analysis have been fabricated, tested, and delivered. This paper discusses the state of the art in (Hg,Cd)Te n-color photoconductive detectors. Included is a discussion of narrow band two-color devices responsive in the region of 8-14 microns. Preliminary results are also included for a unique three-color (Hg,Cd)Te device with cutoff wavelengths of 9.1, 10.8, and 13.8 microns.
Halpert, H.↗
The physical properties of the Jovian atmosphere inferred from eclipses of the Galilean satellites. II - 1971 apparition.
Further simultaneous two-color photoelectric photometry of Ganymede was carried out at blue (4500 A) and yellow (5790 A) wavelengths during its eclipse by Jupiter on Mar. 10, 1971. In both colors, the shape of the ingress light curve was again reliably determined for extinctions up to 9 mag. Neither curve showed any evidence of a refraction tail. The observations have been interpreted in terms of the local optical transmission properties of the Jovian atmosphere. At gas number densities of about 5 x 10 to the 18th power per cu cm the maximum photon scattering mean free path at visual wavelengths was 47 km atm. Evidence indicates that neither a simple reflecting-layer model or a semiinfinite homogeneous scattering model provides an adequate physical description of the atmosphere.
Price, M. J.↗
Electromagnetic free suspension system for space manufacturing. Volume 1: Technology department
The technology developed in defining a facility to be used on the Skylab mission for electromagnetic suspension of small, molten spheres in the weightless space environment is described. The technologies discussed include: four-coil optimization, four-coil versus six-coil configuration comparison, four-coil position servocontrol, four-coil breadboard, position sensing and servosystem, two-color pyrometer, and specimen toration mode analysis.
Buerger, E. H.↗
Investigation of brightness changes of MZ Cas and TZ Cas in B- and V-light
The results are presented concerning statistical processing of two-color observations of MZ Cas and TZ Cas. Light histograms, dispersion and statistical amplitudes are given. Light variations of the variables are represented by normal stochastic processes. Observational data are tabulated.
Lukatskaya, F. I.↗
Multicolor observations of stars in the vicinity of the Orion Nebula.
Photometry in nine colors from 0.3 to 3.4 microns of all stars brighter than V = 12 mag within half a degree square centered on theta super 1 Orionis is presented. Additionally about one-half of this area is searched for stars which, although visually fainter than twelfth magnitude, have 2.2-micron magnitudes brighter than about 8 mag. Several stars with infrared excesses and a few highly reddened stars are found. These two types of stars can be separated in an infrared two-color diagram. No star earlier than B9 has a significant infrared excess at 2 microns. There is a good correlation of 2-micron excess with optical variability. For those stars with spectral types, the visual absorption can be deduced. This varies greatly from star to star and does not correlate with position or luminosity and only weakly with 2-micron excess. There is, however, a probable correlation of visual absorption with optical variability. For nearly all stars more energy is absorbed in the visual region than is reemitted in the infrared at wavelengths up to 3.4 microns.
Penston, M. V.↗
Laser velocimeter measurements of the helicopter rotor-induced flow field
The use of a two-color laser velocimeter to measure the flow velocities in the wake of a helicopter rotor is discussed, including methods for obtaining two components of both instantaneous and time-averaged velocities. Results are presented from an experiment using a 2.13 m diameter model helicopter rotor operating at a tip speed ratio of 0.18 in a wind tunnel. The location of the tip vortex from the preceding blade was determined on the advancing side, and the diameter of the vortex core was found to be 15 percent of the blade chord (1.5 percent of the radius). The effects of the airfoil's bound vorticity were observed in the velocity distributions vry near the blade. These effects suggest that the laser velocimeter may be used to determine the aerodynamic loading (circulation) at a spanwise station on the blade. Also, the structure and boundary of the time-averaged wake were investigated.
Biggers, J. C.↗
An infrared survey of RW Aurigae stars
An infrared photometric survey of 89 RW Aur type variables in both hemispheres has been made. JHKL magnitudes and colors are listed. The RW Aur variables include a small number of highly reddened late-type stars. All T Tauri and hot Orion population stars show infrared excesses and the infrared properties mark certain field stars as being young. The greatest infrared excesses are found for A and F stars while young variable B stars usually show no excesses. The location of the RW Aur stars in the two-color H-K, K-L diagram favor dust re-radiation over free-free emission as the mechanism responsible for the infrared excess. A weak correlation of H-K with emission class links the occurrence of circumstellar dust and gas shells.
Glass, I. S.↗