摘要 :
A survey of the literature on the radiation from the night sky over the wavelength region from 0.4micron to 20microns is presented. The major sources of the radiation,including the airglow and the tropospheric thermal emission,a...
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A survey of the literature on the radiation from the night sky over the wavelength region from 0.4micron to 20microns is presented. The major sources of the radiation,including the airglow and the tropospheric thermal emission,are discussed in detail and their angular,diurnal,seasonal,and latitude dependences described. Other sources,including the stars,moon, zodiacal light,aurora,and noctiluscent clouds are discussed. The data are presented in nine figures showing the absolute value of the zenith spectral brightness over several wavelength intervals between 0.4micron and 20microns. The relationship between the zenith spectral brightness and the brightness seen by an observer viewing along a horizontal path a vertical plane surface illuminated by the airglow is derived in an appendix. (Author)
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摘要 :
Equipment is being developed for the recording and analysis of fluctuations in brightness and color of starlight and daylight, with emphasis on daytime observations. The observations are to provide a possible basis for the study o...
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Equipment is being developed for the recording and analysis of fluctuations in brightness and color of starlight and daylight, with emphasis on daytime observations. The observations are to provide a possible basis for the study of upper atmospheric conditions from the ground. Eight apertures were calibrated by determining the ratios of the photoelectric signals received from an artificial constant source. A search of daytime sky was made with a photometer having a diaphragm which was made with a photometer having a diaphragm which admitted 0.3 square seconds of arc of sky; no relatively high frequency fluctuations were found. Traces at night of stars having comparable brightness showed much greater fluctuation. Measures on the size of nighttime stellar images indicated that stars have an aureole which is detectable photoelectrical but not visually. About 20 to 30% of the light of a star is not visually noticed. The construction may be possible of isophotes of a stellar tremor disk which relate the radius of the disk to the mean total light contained within an area of the radius. (Author).
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Published data on the equatorial airglow are critically reviewed. A number of new results, based primarily on data collected during the IGY, are presented for the oxygen green line and the sodium line. It is shown that the diurnal...
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Published data on the equatorial airglow are critically reviewed. A number of new results, based primarily on data collected during the IGY, are presented for the oxygen green line and the sodium line. It is shown that the diurnal variation of the green line in equatorial regions is markedly different from that in temperate latitudes. (Author)
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摘要 :
An investigation to measure the absolute radiance distribution of the night sky in the spectral region from 1.5 to 3.2 microns is described, together with the instrumentation designed for the study. A 61-cm aperture Newtonian radi...
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An investigation to measure the absolute radiance distribution of the night sky in the spectral region from 1.5 to 3.2 microns is described, together with the instrumentation designed for the study. A 61-cm aperture Newtonian radiometer with an f/2 cast aluminum mirror directed radiation to a 30-element PbS linear array. Individual solid state amplifiers were used for each detector, and total field chopping with electronic zero suppression provided detection for both point and diffuse sources. Each detector subtended a field of view of 1 x 1 minute of arc. Atmospheric and instrumental fluctuations usually limited minimum detectable radiance. Measurements of the Crab Nebula confirm radiance values previously published by Moroz. Results of scans across other known diffuse sources are also reported. Several bright infrared stars were found which do not correspond in position to known late stars. (Author)
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摘要 :
Eleven years' records of observations of the night sky over Fritz Peak (105 deg 29 minW, 39 deg 54 minN) have been examined in a consistent manner to find occurrences of mid-latitude red arcs (SAR-arcs). Those used were nights whe...
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Eleven years' records of observations of the night sky over Fritz Peak (105 deg 29 minW, 39 deg 54 minN) have been examined in a consistent manner to find occurrences of mid-latitude red arcs (SAR-arcs). Those used were nights when the sky was generally clear and the moon absent part or all night. Arcs were found to be present during 29 such nights, with an additional 22 nights with arcs possibly present. The data are described and tabulated. (Author)
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The report is the result of a six month study of the problem of atmospheric extinction and sky brightness effects on the performance of the Baker-Nunn Camera System. This study included the construction of a special sky brightness...
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The report is the result of a six month study of the problem of atmospheric extinction and sky brightness effects on the performance of the Baker-Nunn Camera System. This study included the construction of a special sky brightness photometer,the conduct of 30days of observation in conjunction with the Edwards AFB camera,and the analysis of the results. (Author)
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This technical report describes a ground-based microwave radiometer to measure the atmospheric emission at the frequencies 21.0 and 31.4 GHz. It is a room-temperature dual mixer receiver with two thermal reference loads in each ch...
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This technical report describes a ground-based microwave radiometer to measure the atmospheric emission at the frequencies 21.0 and 31.4 GHz. It is a room-temperature dual mixer receiver with two thermal reference loads in each channel. The reference loads can, depending on the application, be chosen to either 77 and 313 K, or 313 and 360 K. The radiometer is steerable in azimuth and elevation, with an angular resolution of 0.1 degree. The overall design is presented and the effect of extended antenna beams is discussed, as well as data acquisition, data reduction, and the accuracy of measured sky brightness temperatures.
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摘要 :
Zenith intensity measurements of the 5577 (OI) green line of the night airglow taken at Sacramento Peak, New Mexico, previous to the International Geophysical Year are presented in tabular form. A discussion on the present knowled...
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Zenith intensity measurements of the 5577 (OI) green line of the night airglow taken at Sacramento Peak, New Mexico, previous to the International Geophysical Year are presented in tabular form. A discussion on the present knowledge of the night airglow features, instrumentation, and calibration of the instruments is also included. (Author)
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