Reduction of mutual coupling using perfectly conducting fences
Thin perfectly conducting fences used to reduce mutual coupling of two parallel plane waveguides
Mailloux, R. J.↗
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Mutual phenomena of Jupiter's satellites in 1973-74.
Discussion of a program draft for worldwide observations of mutual occultations and eclipses of the Jovian satellites. The purpose of the observations planned for 1973 and 1974 is to obtain light curves of these events with a relative photometric accuracy of no less than 1%. A time table of the anticipated events is included.
Brinkmann, R. T.↗
Mutual coupling between circular waveguide-fed apertures in a rectangular ground plane
A method is presented whereby the infinite ground plane analytical model for the self-admittance and mutual admittance of waveguide-fed apertures can be supplemented (using the geometrical theory of diffraction) to include the edge effects of a rectangular ground plane. The H-plane coupling between two TE-11 mode excited circular apertures is calculated and compared with measurements.
Bailey, M. C.↗
Galilean satellites - Observations of mutual occultations and eclipses in 1973
Seven Galilean satellite mutual events, two occultations and two eclipses of Europa and three eclipses of Io, were observed at three wavelengths (0.35, 0.50, 0.91 micrometers) with a time resolution of 0.1 sec. Preliminary model fits to the light curves are presented. Model satellites with different albedo distributions (uniform disk, bright solar caps, bright quadrant) are used in generating model occultation and eclipse curves to demonstrate the sensitivity of observed light curves to the brightness distribution on the surface of the occulted or eclipsed satellite. At the present the observations yield no conclusive information of the limb-darkening of Io. The best data for Europa indicate that the satellite is limb-darkened at both 0.50 and 0.91 micrometers.
Wasserman, L. H.↗
Mutual admittance between circular waveguide-fed apertures for large spacing
A closed-form asymptotic expression for the mutual admittance between two circular waveguide-fed apertures is developed for large element spacings. A comparison with calculations obtained by a numerical integration method indicated that the present analysis gives good results for spacings greater than two wavelengths.
Bailey, M. C.↗
Mutual phenomena of Saturn's satellites in 1979-1980
Using two sets of orbital elements and the radii of the Saturnian satellites 1 (Mimas) through 7 (Hyperion), we find that from October 1979 until August 1980 nearly 300 mutual eclipses and occultations involving these bodies will occur. To allow for the expected errors in the satellite ephemerides, we repeat these calculations in order to obtain the additional events that occur when all satellite radii (save Titan's) are increased by 1000 km. A third listing predicts eclipses of satellites by (the shadow of) the ring. Photometric observations of a large number of these events will add much precise information to our knowledge of the Saturnian system at a critical time.
Aksnes, K.↗
Sunspots and the physics of magnetic flux tubes. V - Mutual hydrodynamic forces between neighboring tubes
The mutual hydrodynamic forces between parallel cylinders in a moving fluid are illustrated through several formal examples. Parallel tubes in a uniform flow are attracted or repelled depending on whether they are side by side or one ahead of the other, respectively. A pulsating or undulating tube attracts all other neighboring tubes toward itself. These hydrodynamic effects suggest that the separate flux tubes beneath the sunspots exert significant attractive forces on each other.
Parker, E. N.↗
Extensions to the classical calculation of the effect of mutual shadowing in diffuse reflection
The classical method for accounting for the mutual shadowing among closely packed particles in multiple scattering calculations is extended in the following ways. (1) By modeling the particle distribution by a Poisson process with a varying density parameter, a 'Van der Waals' type approximation allows extension to a greater fractional volume density, D. In this case it is only required that D squared be much less than 1 instead of D being much less than 1. (2) In the case that the particle distribution is not uniform the classical calculation may be weighted by the pair correlation function of the distribution. (3) The use of the Markov chain formalism for radiative transfer allows inclusion of the effect of shadowing for two orders of scattering. For conditions such as might apply in Saturn's rings, the inclusion of this effect makes less than a 0.1% difference in the calculated phase curves, compared to previous calculations which have included shadowing only in the first scattering. The latter are thus shown to be quite accurate.
Esposito, L. W.↗
Reconstruction of the mutual coherence function for a moving source
The acoustic radiation of a randomly fluctuating source in motion is characterized analytically to determine the mutual coherence function (MCF). A far-field relation is derived via a series of invertible transformations, and a higher-dimension Radon transformation is performed to reconstruct the MCF; explicit formulas for computing the MCF from the transformed radiation data are provided. The technique is applied to the cases of an axisymmetric line source of finite extent moving at constant velocity along a line and a spatially incoherent line source. Applications to X-ray tomography and analysis of the noise emitted by a moving jet aircraft are suggested.
Chow, P. L.↗
Mutual effect of thermochemical surface decomposition and viscous interaction during hypersonic flow past a sharp cone
Numerical results on the hypersonic gas flow in viscous interaction regime past sharp circular cones with thermally destructible Teflon surface are presented. Characteristics of the mutual influence between the thermochemical decomposition of the surface and the viscous interaction are revealed.
Limanskiy, A. V.↗
Mutual coupling effects in antenna arrays, volume 1
Mutual coupling between rectangular apertures in a finite antenna array, in an infinite ground plane, is analyzed using the vector potential approach. The method of moments is used to solve the equations that result from setting the tangential magnetic fields across each aperture equal. The approximation uses a set of vector potential model functions to solve for equivalent magnetic currents. A computer program was written to carry out this analysis and the resulting currents were used to determine the co- and cross-polarized far zone radiation patterns. Numerical results for various arrays using several modes in the approximation are presented. Results for one and two aperture arrays are compared against published data to check on the agreement of this model with previous work. Computer derived results are also compared against experimental results to test the accuracy of the model. These tests of the accuracy of the program showed that it yields valid data.
Collin, R. E.↗
Pluto-Charon mutual event predictions for 1986
Circumstances are tabulated for 81-Pluto-Charon mutual events occurring during the 1986 opposition. The deepest and longest events will occur in February and reach a depth of about 0.15 mag. Observations of these events will lead to an accurate determination of the satellite's orbit, the diameters of the two bodies, the mean density of the system, and crude albedo maps of one hemisphere on each object.
Tholen, D. J.↗
Spectrophotometry of Pluto-Charon mutual events - Individual spectra of Pluto and Charon
Time-resolved spectra of the March 3 and April 4, 1987 mutual events of Pluto and Charon, obtained with spectral coverage from 5500 to 10,000 A with 25-A spectral resolution, are discussed. Charon has a featureless reflectance spectrum, with no evidence of methane absorption. Charon's reflectance appears neutral in color and corresponds to a geometric albedo of about 0.37 at 6000 A. The Pluto reflectance spectrum displays methane absorption bands at 7300, 7900, 8400, 8600, and 8900 A and is red in color, with a geometric albedo of about 0.56 at 6000 A.
Sawyer, S. R.↗
Circumstances for Pluto-Charon mutual events in 1988
Physical parameters are tabulated for 89 Pluto-Charon mutual events occurring during the 1988 opposition. A primary star and a check star have been selected as comparison stars for events occurring prior to the 1988 opposition. Standardization of the comparison star 1987 Primary has provided a B magnitude of 12.3093 + or - 0.0013 and a V magnitude of 11.4215 + or - 0.0013. The designations, positions, and preliminary magnitudes and colors are also given for two transformation stars selected in order to aid in determination of the color terms necessary to convert the instrumental magnitudes of observers to the standard system.
Tholen, David J.↗
No effect of diffraction on Pluto-Charon mutual events
Mulholland and Gustafson (1987) made the interesting suggestion that observations of Pluto-Charon mutual events might show significant dependence on both wavelength and telescope aperture because of diffraction effects. In this letter, observations are presented that show the predicted effects to be absent and demonstrate that the parameters of the system are such that the events can be accurately analyzed with geometrical optics.
Tholen, D. J.↗
Circumstances for Pluto-Charon mutual events in 1989
Circumstances for 90 Pluto-Charon mutual events occurring during the 1989 opposition are presented. It is found that the deepest and longest events will occur near postopposition quadrature in early August. Two new stars are selected as comparison stars for events occurring before opposition in 1989, and it is noted that the 1988 comparison stars should be used for events occurring after opposition.
Tholen, David J.↗
Mutual coupling between electromagnetically coupled rectangular patch antennas
Measured mutual coupling between two X-band electromagnetically coupled rectangular patch antennas is reported. Results are given for both the wideband and high gain regions as well as for E-plane and H-plane couplings.
Lee, R. Q.↗
The year 1990 marks end of Pluto-Charon mutual event season
From late 1984 until late 1990, the orbit of Pluto's satellite Charon was sufficiently close to an edge-on configuration, as seen from Earth, to produce transit, occultation, and eclipse events involving the two objects. The systematic observation of these events, each of which offers a unique geometry of Pluto, Charon and shadow, has been used to directly measure several parameters of the system. With data now available from the entire mutual event season, reliable values for the radii of Pluto and Charon can be derived. Pluto's radius is 0.05860 plus or minus 0.00031, in units of Chiron's mean orbital radius, and Charon's radius is 0.03019 plus or minus 0.00066, in the same units.
Tholen, David J.↗