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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Visual observations from space

Visual observations from space reveal a number of fascinating natural phenomena of interest to meteorologists and aeronomists, such as aurorae, airglow, aerosol layers, lightning, and atmospheric refraction effects. Other man-made radiation, including city lights and laser beacons, are also of considerable interest. Of course, the most widely used space observations are of the large-scale weather systems viewed each day by millions of people on their local television. From lower altitudes than the geostationary meteorological satellite orbits, obliques and overlapping stereo views are possible, allow height information to be obtained directly, often a key element in the use of the photographs for research purposes. However, this note will discuss only the less common observations mentioned at the beginning of this paragraph.

Garriott, O. K.↗
NASA NTRS1974

Visual observations from space

A visual observations project was established as part of the Skylab experimental program in order to optimize the collection of scientific data during the 84-day Skylab 4 mission. One objective of this project was the determination of the capabilities of the crewmen in the visual identification of various types of surface, air, and water phenomena of the earth which may be observed from the Skylab orbit. Another objective was a study of the possibilities provided by visual observations, supplemented by photographs, in the support of scientific investigations. Aspects of premission preparations are considered along with details concerning the equipment to be used and questions of mission operations. The results of the project show that the presence of man in an earth-observations program contributes a significant additional capability which is not available with a totally automated program.

Lenoir, W. B.↗
NASA NTRS1972

Visual observations from lunar orbit, part A

Visual observations from Apollo 15 lunar orbits are discussed, complementing photographic and other remotely sensed data. Color tone of surface units, global tectonic trends, and small scale features are considered. Visual observations were made on Tsiolkovsky Crater, swirls in Mare Marginis, Picard Crater region, Proclus Crater, Littrow Crater area, landing site area, flow fronts in Mare Imbrium, and Aristarchus Plateau.

El-Baz, F.↗
NASA NTRS1991

The modern role of visual observations of comets

This paper reviews the role of past and future visual observations in cometary research. The strengths and limitations of visual observations are explored for the benefit of both investigators who might have to use them and observers who wish to make real contributions to the field. We consider the characteristics of the eye-brain combination as a detector and compare them with those of modern detectors. We specifically evaluate visual discoveries, magnitude estimates, and drawings.

Larson, S. M.↗
NASA NTRS1989

The Modern Role of Visual Observations of Comets

This paper reviews the role of past and future visual observations in cometary research. The Strengths and limitations of visual observations are explored for the benefit of both investigators who might have to use them and observers who wish to make real contributions to the field.

Comets↗
NASA NTRS1974

Skylab 4 visual observations project report

The Skylab 4 Visual Observations Project was undertaken to determine the ways in which man can contribute to future earth-orbital observational programs. The premission training consisted of 17 hours of lectures by scientists representing 16 disciplines and provided the crewmen information on observational and photographic procedures and the scientific significance of this information. During the Skylab 4 mission, more than 850 observations and 2000 photographs with the 70-millimeter Hasselblad and 35-millimeter Nikon cameras were obtained for many investigative areas. Preliminary results of the project indicate that man can obtain new and unique information to support satellite earth-survey programs because of his inherent capability to make selective observations, to integrate the information, and to record the data by describing and photographing the observational sites.

Kaltenbach, J. L.↗
NASA NTRS1971

The visual observation of comets

Comets structural features via visual observations, emphasizing inner coma structures and expanding envelopes surrounding nucleus

Donn, B.↗
NASA NTRS1975

Skylab-4 visual observations project: Geological features of southwestern North America

Visual observations conducted by Skylab-4 crewmen on seven designated geological target areas and other targets of opportunity in parts of southwestern United States and northwestern Mexico were described. The experiments were designed to learn how effectively geologic features could be observed from orbit and what research information could be obtained from the observations when supported by ground studies. For the limited preparation they received, the crewmen demonstrated exceptional observational ability and produced outstanding photographic studies. They also formulated cogent opinions on how to improve future observational and photo-documentation techniques. From the photographs and other observations, it was possible to obtain significant research contributions to on-going field investigations. These contributions were integrated into other aspects of the ground investigations to the following topics: major faults, regional stratigraphy, occurrence of Precambrian crystalline rocks, mapping of Mesozoic volcanic rocks, regional geology.

Silver, L. T.↗
NASA NTRS1999

In-Situ Partial Pressure Measurements and Visual Observation during Crystal Growth of ZnSe by Seeded Physical Vapor Transport

An in-situ monitoring furnace was constructed with side windows to perform partial pressure measurements by optical absorption and visual observation of the growing crystal. A fused silica -rowth ampoule with a 4.5 cm long square tube between the source and the seed was prepared for the optical absorption measurements. A ZnSe crystal was grown by the seeded physical vapor transport (PVT) technique in the horizontal configuration. The growth temperature was 1120 C and the furnace translation rate was 3nmVday. Partial pressures of Se2, P(sub Se2), at three locations along the length of the growth ampoule were measured at 90 min intervals during the growth process. The measured P (sub Se2) were in the range of 2.0 to 6.5 x 10(exp -3) atm. The P(sub Se2) results indicated that the partial pressure profile was inconsistent with the results of the one-dimensional diffusion mass transport model and that the source composition shifted toward Se-rich during the run, i.e. the grown crystal was more Zn-rich than the source. The visual observation showed that the seed crystal first etched back, with greater thermal etching occurring along the edges of the seed crystal. Once the growth started, the crystal crew in a predominately contactless mode and facets were evident during growth. The crystal did not grow symmetrically which is believed to be due to the unintentional asymmetry of the radial thermal profile in the furnace.

Su, Ching-Hua↗