The astrometry network of observers in Japan
The astrometric network of observers and the main telescopes for professional and amateur astronomers in Japan and their availability for the International Halley Watch (IHW) are described.
Engineering topics
Publications and source records attributed to Kozai, Y..
The astrometric network of observers and the main telescopes for professional and amateur astronomers in Japan and their availability for the International Halley Watch (IHW) are described.
A sequence of advances in the determination of geodetic parameters presented by the Smithsonian Astrophysical Observatory are described. A Baker-Nunn photographic system was used in addition to a ruby-laser ranging system to obtain data for refinement of geodetic parameters. A summary of the data employed to: (1) derive coordinates for the locations of various tracking stations; and (2) determine the gravitational potential of the earth, is presented.
The paper discusses the advantages and disadvantages of adopting either an inertial or a noninertial reference system for computing the orbital elements of artificial satellites. The effects of precession and nutation are examined, and determination of disturbing functions is explained for both an inertial and a noninertial system.
Exact differential equations relating the perturbations to satellite orbital elements by the motion of the earth's equatorial plane are derived, and they are solved to second order in precession. The system proposed in a previous paper (Kozai, 1960), in which the inclination and the argument of perigee are referred to the equator of date and the longitude of the ascending node is measured from a fixed point along a fixed plane and then along the equator of date, can still be recommended for precise studies of satellite motion even when the second-order perturbations are taken into account.
A new method to compute lunisolar perturbations in satellite motion is proposed. The disturbing function is expressed by the orbital elements of the satellite and the geocentric polar coordinates of the moon and the sun. The secular and long periodic perturbations are derived by numerical integrations, and the short periodic perturbations are derived analytically. The perturbations due to the tides can be included in the same way. In the Appendix, the motion of the orbital plane for a synchronous satellite is discussed; it is concluded that the inclination cannot stay below 7 deg.
Annual variation of geopotential determined by tracking satellites
Revised coefficient values of zonal spherical harmonics in geopotential
Coefficients of zonal spherical harmonics in geopotential from reduced Baker-Nunn data for 10 satellites
Determination of Love number of earth from variations of orbital inclinations of satellites
Lunisolar short-periodic perturbations and lunar perturbations
Expressions for second order short periodic perturbations for satellite motion
Numerical integration of equations of motion for Explorer VI satellite - lunar, solar, oblateness, and atmospheric drag perturbations
Zonal harmonics coefficient determination of earth gravitational potential
Geodetic data and values for the coefficients of zonal harmonics in the earth potential from orbits of artificial satellites
Tesseral harmonics of the potential of the earth as derived from satellite motions