The lunar crescent and earthshine observed at 2 deg solar elongation
Analyses of lunar crescent and earthshine observed at 2 deg solar elongation
Koomen, M. J.↗
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The lunar crescent and earthshine observed at 2 deg solar elongation.
Lunar crescent and earthshine at 2 degrees solar elongation, discussing occulted coronagraph photography, mean solar brightness and surface fluorescence
Koomen, M. J.↗
Observations of the 1969 inferior conjunction and greatest western elongation of Venus - Data catalog and preliminary analysis
Observations of 1969 inferior conjunction and greatest western elongation of Venus, and Earth sky brightness effects on data - catalog and preliminary analysis
Kocher, G. E.↗
Low-Speed Aerodynamic Characteristics of a Fuselage Model with Various Arrangements of Elongated Lift Jets
Data were obtained for a round jet located on the center of the bottom of a fuselage and for elongated slots separated spanwise by distances of 0.8 and 1.2 of the fuselage width. The effect of yawing the slots, inclining the jets laterally, and combining slot yaw with jet inclination was determined. Data were obtained in and out of ground effect through a range of effective velocity ratios and through a range of sideslip angles.
Vogler, R. D.↗
Plasma column changes at small solar elongations
The differenced range versus integrated Doppler (DRVID) technique was used to study charged particle changes in the ray path between earth and Mariner 9. For plasma activity near the sun, DRVID data were obtained from August 10 to October 24, 1972, surrounding the Mariner 9 superior conjunction on September 7. If the records are viewed in terms of range change or range change rate, the day-to-day fluctuations in these quantities mask the changes expected due to the varying solar elongation. Thus, while the steady-state total electron content varies by a factor of 4, the columnar content changes show no systematic variations.
Callahan, P. S.↗
Plasma column changes at small solar elongations.
By using the difference between phase and group velocities in a plasma, the changes in the columnar content between earth and Mariner 9 have been measured for elongations of 3 to 16 deg. Rates of change were observed up to 2.5 x 10 to the minus 15th electrons per sq m per sec. Structures of 3,000,000 km in size could be inferred.
Callahan, P. S.↗
Effects of various experimental parameters on errors in triangulation solution of elongated object in space
The effects of various experimental parameters on the displacement errors in the triangulation solution of an elongated object in space due to pointing uncertainties in the lines of sight have been determined. These parameters were the number and location of observation stations, the object's location in latitude and longitude, and the spacing of the input data points on the azimuth-elevation image traces. The displacement errors due to uncertainties in the coordinates of a moving station have been determined as functions of the number and location of the stations. The effects of incorporating the input data from additional cameras at one of the stations were also investigated.
Long, S. A. T.↗
The solar elongation distribution of low-frequency radio bursts
Over 500 days of low-frequency (less than 1 MHz) radio observations from the IMP-6 spacecraft have been accumulated to produce a two-dimensional map (frequency vs elongation) of solar type III burst occurrences. This map indicates that most solar bursts in this frequency range are observed at the second harmonic of the plasma frequency, rather than the fundamental. The map also shows that the solar wind electron density varies as an inverse power of heliocentric distance, with the exponent somewhat less than 2 to perhaps 3 or higher.
Kaiser, M. L.↗
Ultraviolet spectroscopy of the zodiacal light at 20-deg elongation
The zodiacal light at 20-deg elongation and 10-deg inclination was observed by rocket ultraviolet spectrometers at 10-15-A resolution in the spectral range 1200-3200 A during an experiment designed to observe comet Kohoutek (1973 XII). The data were obtained above 180 km when scattered horizon light in the startracker caused a loss of tracking on the comet. Airglow emission due to NO and O(+), identified spectroscopically and by its variation with altitude, is significant between 1900 and 2500 A. Longward of 2600 A, the spectrum matches that of the sun, and the derived value of the color ratio, relative to the visible, is 0.90 + or - 0.20. At 1600 A, an upper limit on the zodiacal-light emission of 0.07 R per A or 7 hundred-millionths erg/s per sq cm/sterad per A is obtained.
Feldman, P. D.↗
Hektor - The largest highly elongated asteroid
New observations of Trojan asteroid 624, Hektor, in April 1979 establish that the high amplitude of the rotational light curve of this object is caused by its elongated shape and not by patches of dark and light albedo on opposing hemispheres. These observations confirm the fact that Hektor is a very unusual object and are consistent with the hypothesis that it may be a compound asteroid formed when two Trojans of comparable size fell together - a rare fossilized example of a planetary accretion process.
Hartmann, W. K.↗
Equatorial plasma bubbles - Vertically elongated wedges from the bottomside F layer
The possible depletion of plasma bubbles associated with the equatorial spread-F phenomenon was examined in terms of plumes mapped with the ALTAIR radar and bubbles measured by ion-drift meter on board the Explorer E satellite. The meter measured the east-west spatial relationship of ion-density depletions. The plasma bubbles were found to be vertically elongated depletions extending downward from the bottom side of the F layer in the form of tilted wedges. The electrodynamics of the bubbles correspond with observations of large eastward drift velocities of plumes comparable to the F region drift measurements. It was also determined that the west wall of large scale altitude modulations of the bottomside F layer becomes structured and evolves with the generation of secondary plumes and bubbles.
Tsunoda, R. T.↗
Evidence for parallel elongated structures in the mesosphere
The physical cause of partial reflection from the mesosphere is of interest. Data are presented from an image-forming radar at Brighton, Colorado, that suggest that some of the radar scattering is caused by parallel elongated structures lying almost directly overhead. Possible physical sources for such structures include gravity waves and roll vortices.
Adams, G. W.↗
The effect of water temperature and synoptic winds on the development of surface flows over narrow, elongated water bodies
Simulations of the thermally induced breeze involved with a relatively narrow, elongated water body is presented in conjunction with evaluations of sensible heat fluxes in a stable marine atmospheric surface layer. The effect of the water surface temperature and of the large-scale synoptic winds on the development of surface flows over the water is examined. As implied by the sensible heat flux patterns, the simulation results reveal the following trends: (1) when the synoptic flow is absent or light, the induced surface breeze is not affected noticeably by a reduction of the water surface temperature; and (2) for stronger synoptic flow, the resultant surface flow may be significantly affected by the water surface temperature.
Segal, M.↗
Measuring Hole Elongation in Bolted Joints
Measurement does not affect joint parameters. Verification of analytical and strength-prediction methods for bolted composite joints based generally on data obtained experimentally from double-lap-joint specimens. In mechanically fastened joints, stresses maximal at fastener holes. Ability to measure accurately hole elongations without affecting joint parameters provides better understanding of elastic and plastic behavior of joint material leading to failure mechanisms in mechanically fastened joints required for design of more-efficient, lightweight composite joints.
Wichorek, G. R.↗
Trojan and Hilda asteroid lightcurves. I - Anomalously elongated shapes among Trojans (and Hildas?)
A comparison of the available sample of lightcurves for 26 Trojan and Hilda asteroids with belt asteroid lightcurves shows the former to be distinguished by a higher incidence of high amplitudes rgan belt asteroids of comparable size, suggesting more elongated shapes; they currently have, moreover, only a few percent of the main-belt asteroids' collision frequency. A more modest collisional evolution that may have affected the relative degree of fragmentation of these bodies, and thus their shapes, is inferred.
Hartmann, William K.↗
Laser diffraction particle sizing: Instrument probe volume relocation and elongation
The effective probe volume of laser diffraction particle sizing instruments depends on many instrument parameters. In particular the probe volume axial boundaries and its location along laser beam are essentially defined by the onset of a vignetting effect where light scattered at large angles from small particles misses the transform lens. This vignetting effect results in a probe volume that must be inconveniently close to the lens in order to detect smaller diameter particles (less than 100 micrometers). With the addition of an appropriately designed Keplerian telescope, the probe volume may be relocated and elongated. The theory of operation of this supplemental optical system is described. Design considerations for these supplemental optical systems are described, including recommendations for lens specifications, assembly and use. An image transfer system is described which has been designed for use on a Malvern 2600HSD instrument. Experimental validation of this image transfer system is described.
Anderson, Robert C.↗
Fragmentation of elongated cylindrical clouds. IV - Clouds with solid-body rotation about an arbitrary axis
Results of 3D hydrodynamic collapse calculations of elongated isothermal clouds with solid-body rotation about an arbitrary axis are presented. Four different modes of fragmentation are identified. In all evolutions that formed more than one fragment, a structural fragmentation mode occurred first, forming condensations on each side of the cylinder. It is shown that gravitational torques and tidal effects control most of the fragmentation and coalescence which occur. The fragmentation processes and gravitational torques can also reduce the fragment's specific angular momentum by up to two orders of magnitude compared to that of the parent cloud. This is consistent with the inferred value of the specific angular momentum of the initial protosolar nebula.
Bonnell, Ian↗
Note on the pressure distribution over the hull of elongated airships with circular cross section
This note, prepared for the National Advisory Committee for Aeronautics, contains the demonstration that the pressure around the circular cross section of an elongated airship, plotted against the diameter of symmetry, can be expected to be represented by a straight line.
Munk, Max M↗