Applied Orbit Perturbation and Maintenance, Second Edition

2017 ◽  
Author(s):  
Chia-Chun “George” Chao ◽  
Felix Hoots
Keyword(s):  
Orbit Perturbation

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

Ligand Field-Spin Orbit Energy Levels in the d4 and d6 Electron Configurations of Octahedral and Tetrahedral Symmetry

1974 ◽  
Vol 29 (1) ◽  
pp. 31-41 ◽  
Author(s):  
E. König ◽  
S. Kremer
Keyword(s):  
Strong Field ◽  
Energy Levels ◽  
Coulomb Repulsion ◽  
Orbit Interaction ◽  
Complete Agreement ◽  
Ligand Field ◽  
Spin Orbit ◽  
Tetrahedral Symmetry ◽  
Spin Orbit Interaction ◽  
Orbit Perturbation

The complete ligand field -Coulomb repulsion -spin orbit interaction matrices have been derived for the d4 and d6 electron configurations within octahedral (Oh) and tetrahedral (Td) symmetry. The calculations were perform ed in both the weak-field and strong-field coupling schemes and complete agreement of the results was achieved. The energy matrices are parametrically dependent on ligand field (Dq), Coulomb repulsion (B, C) and spin-orbit interaction (ζ). Correct energy diagrams are presentend which display the splittings by spin-orbit perturbation as well as the effect of configuration mixing. Applications to the interpretation of optical spectral data, to the detailed behavior at the crossover of ground terms, and to complete studies in magnetism are pointed out.

scholarly journals Ligand-Field Spin-Orbit Energy Levels in the d5 Electron Configuration of Octahedral and Tetrahedral Symmetry

1974 ◽  
Vol 29 (3) ◽  
pp. 419-428 ◽  
Author(s):  
E. König ◽  
R. Schnakig ◽  
S. Kremer
Keyword(s):  
Strong Field ◽  
Energy Levels ◽  
Orbit Interaction ◽  
Complete Agreement ◽  
Ligand Field ◽  
Electron Configuration ◽  
Spin Orbit ◽  
Tetrahedral Symmetry ◽  
Spin Orbit Interaction ◽  
Orbit Perturbation

The complete ligand-field, Coulomb interelectronic repulsion, and spin-orbit interaction matrices have been derived for the d5 electron configuration within octahedral (Oh) and tetrahedral (Td) symmetry. The calculations were performed in both the weak-field and strong-field coupling schemes and complete agreement of the results was achieved. The energy matrices are parametrically dependent on ligand field (Dq), Coulomb repulsion (B, C), and spin-orbit interaction (ζ). Correct energy diagrams are presented which display the splittings by spin-orbit perturbation as well as the effect of configuration mixing. Applications to the interpretation of electronic spectra, and to complete studies in magnetism are pointed out. The detailed behavior at the crossover of ground terms is considered

Examination and Enhancement of solar radiation pressure model for BDS-3 satellites

2021 ◽  
Author(s):  
Jie Li ◽  
Yongqiang Yuan ◽  
Shi Huang ◽  
Chengbo Liu ◽  
Jiaqing Lou ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Radiation Pressure ◽  
Elevation Angle ◽  
Precise Orbit Determination ◽  
Orbital Plane ◽  
Solar Radiation Pressure ◽  
Earth Orbit ◽  
Precise Orbit ◽  
Orbit Perturbation ◽  
Geo Satellites

<p>With the successful launch of the last Geostationary Earth Orbit (GEO) satellite in June 2020, China has completed the construction of the third generation BeiDou navigation satellites system (BDS-3). BDS-3 global services have been initiated in July 2020 with the constellation of 3 GEO, 3 Inclined Geosynchronous Orbit (IGSO) and 24 Medium Earth Orbit (MEO) satellites. In order to further improve the performance of BDS-3 services, the quality of BDS-3 precise orbit product needs further enhancements.</p><p>       The solar radiation pressure (SRP) is the main non-conservative orbit perturbation for GNSS satellites and is the key to improve BDS-3 precise orbit determination. In this study, we focus on the SRP models for BDS-3 satellites. Firstly, the widely used Extended CODE Orbit Model with five parameters (ECOM-5) is assessed. With one-year observations of 2020 from both iGMAS and MGEX networks, the five parameters of ECOM model (D0, Y0, B0, Bc and Bs) are estimated for each BDS-3 satellite. The D0 estimates show an obvious dependency on the elevation angle of the Sun above the satellite orbital plane (denoted as β). In addition, large variations can be noticed in eclipse seasons, which indicate the dramatic changes of SRP. The Y0 estimates vary from -0.6 nm/s<sup>2</sup> to 0.6 nm/s<sup>2</sup> for MEO, -1.0 to 1.0 nm/s<sup>2</sup> for IGSO and -1.0 to 1.5 nm/s<sup>2</sup> for GEO satellites. The B0 estimates of several satellites exhibit a clear dependency on the β angle. The largest variation of B0 appears at C45 and C46, changing from 1.0 nm/s<sup>2</sup> at 15 deg to 8.3 nm/s<sup>2</sup> at 64 deg, which implies that the solar panels of these two satellites may have an obvious rotation lag. To compensate the deficiencies of BDS-3 SRP modeling, we introduce several additional parameters into ECOM-5 model (e.g. introducing higher harmonic terms). The POD performances can be improved by about 10% and 40% for BDS-3 MEO/IGSO and GEO satellites, respectively.</p><p>       Except for the empirical model, we also study the semi-empirical SRP model such as the a priori box-wing model. Since the geometrical and optical properties from BDS-3 metadata are general and rough, we apply more detailed geometrical and optical coefficients for BDS-3 satellites. The POD performance can be improved by about 10% compared to empirical SRP models. Furthermore, considering Earth radiation pressure will have an impact of about 1.3 cm in radial component for MEO satellites.</p>

Crystal field-spin orbit perturbation calculations in d2 and d8 trigonal bipyramidal complexes

1970 ◽  
Vol 74 (7) ◽  
pp. 1568-1585 ◽  
Author(s):  
Clifford A. L. Becker ◽  
Devon W. Meek ◽  
Thomas M. Dunn
Keyword(s):  
Crystal Field ◽  
Spin Orbit ◽  
Trigonal Bipyramidal ◽  
Orbit Perturbation

Orbit Plan Method for General Rendezvous Problems

2014 ◽  
Vol 543-547 ◽  
pp. 1385-1388
Author(s):  
Xu Min Song ◽  
Yong Chen ◽  
Qi Lin
Keyword(s):  
Optimization Problem ◽  
Planning Problem ◽  
Shooting Technique ◽  
Lambert Problem ◽  
Orbit Perturbation ◽  
Eccentric Orbits ◽  
Rendezvous Problem ◽  
Transfer Orbit ◽  
Adaptive Simulated Annealing ◽  
Annealing Method

The orbit plan method of rendezvous mission was studied in this paper. We are concerned with the general rendezvous problem between two satellites which may be in non-coplanar, eccentric orbits, considering orbit perturbation and rendezvous time limitation. The planning problem was modeled as a nonlinear optimization problem, and the adaptive simulated annealing method was used to get the global solution. The Lambert algorithm was used to compute the transfer orbit, so that the endpoint constraint of rendezvous was eliminated. A shooting technique was used to solve the perturbed lambert problem. The method was validated by simulation results.

scholarly journals Orbit perturbation analysis of West Ford needles clusters

2000 ◽  
Author(s):  
Bruce Bowman ◽  
William Barker ◽  
William Schick
Keyword(s):  
Perturbation Analysis ◽  
Orbit Perturbation
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