Search arXivSearch

arXiv · 2107.12223

Relativistic positioning: including the influence of the gravitational action of the Sun and the Moon and the Earth's oblateness on Galileo satellites

Abstract

Uncertainties in the satellite world lines lead to dominant positioning errors. In the present work, using the approach presented in \cite{neu14}, a new analysis of these errors is developed inside a great region surrounding Earth. This analysis is performed in the framework of the so-called Relativistic Positioning Systems (RPS). Schwarzschild metric is used to describe the satellite orbits corresponding to the Galileo Satellites Constellation. Those orbits are circular with the Earth as their centre. They are defined as the nominal orbits. The satellite orbits are not circular due to the perturbations they have and to achieve a more realistic description such perturbations need to be taken into account. In \cite{neu14} perturbations of the nominal orbits were statistically simulated. Using the formula from \cite{col10a} a user location is determined with the four satellites proper times that the user receives and with the satellite world lines. This formula can be used with any satellite description, although photons need to travel in a Minkowskian space-time. For our purposes, the computation of the photon geodesics in Minkowski space-time is sufficient as demonstrated in \cite{neu16}. The difference of the user position determined with the nominal and the perturbed satellite orbits is computed. This difference is defined as the U-error. Now we compute the perturbed orbits of the satellites considering a metric that takes into account the gravitational effects of the Earth, the Moon and the Sun and also the Earth oblateness...

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Neus Puchades Colmenero, José Vicente Arnau Córdoba, Màrius Josep Fullana i Alfonso. 2021-07-23. Relativistic positioning: including the influence of the gravitational action of the Sun and the Moon and the Earth's oblateness on Galileo satellites. https://doi.org/10.1007/s10509-021-03973-z

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Quantum Correlations of Neutrinos in the Kerr-Newman Space-time

Quantum phases establish a connection between gravitation and quantum information, offering a novel avenue for exploring the properties of space-time. In this paper, we investigate the quantum correlations (QCs) of neutrinos in the Kerr--Newman space-time for both zero- and nonzero-angular-momentum propagation. The results show that, for zero-angular-momentum propagation, the oscillation periods of the survival probability and QCs progressively decrease with propagation distance in the inward direction. In the outward direction, increasing $M$ lengthens the oscillation periods of $P_{ν_e\rightarrowν_e}$, entanglement, and the monogamy of nonlocality, whereas increasing the angular momentum $a$ or charge $Q$ shortens them. For nonzero-angular-momentum propagation, the metric parameters also generate local profile modulations through additional two-path interference terms, rather than merely rescaling the oscillation period. Furthermore, we find that, despite differences in their ranges of variation, entanglement and coherence exhibit highly consistent oscillatory behavior in both propagation cases. These findings provide a comprehensive understanding of neutrino-based relativistic quantum information.

gr-qc

Tidal Love numbers of wormholes as black-hole mimickers

We study the dynamical scalar tidal Love numbers of wormholes that provide viable mimickers for black holes, focusing on thin-shell Schwarzschild and Damour-Solodukhin geometries. Using a matched near- and far-zone expansion, we determine their tidal response in the low-frequency regime. The presence of a long throat introduces an additional characteristic scale and naturally separates the modes into two classes. Super-throat modes probe the global wormhole geometry and are sensitive to both asymptotic regions, whereas sub-throat modes probe only one side of the wormhole and effectively perceive the throat as a black-hole horizon. We derive the scalar tidal Love numbers analytically for both classes of modes and show that their dissipative parts exhibit distinct low-frequency behavior, reflecting whether one or both potential barriers participate in the scattering process. We further find that, as the wormhole approaches the black-hole limit, the super-throat contribution becomes progressively negligible, while the sub-throat response smoothly reduces to that of a Schwarzschild black hole. These results demonstrate that the tidal response of wormholes depends crucially on whether the perturbation probes the global structure of the throat.

gr-qc

Effective Matter Conversion in Gravitational Collapse and the Dynamical Formation of Regular Black Holes

We study inverse source reconstruction in generalized Vaidya spacetimes. A prescribed density fixes the mass and tangential pressure, while a two-sector decomposition determines a dimensionless radial balance function. We distinguish this function from a time-directed conversion rate and identify the additional null-flux information required for a covariant exchange vector. Positivity restricts the allowed target pressures: a de Sitter core cannot be represented by nonnegative sectors with nonnegative tangential equations of state. An explicit finite-density profile admits a positive vacuum-like completion, finite curvature invariants, and inner and outer trapping horizons above a calculable threshold. Its total source satisfies the null, weak, and dominant energy conditions during monotonic accretion, while the timelike convergence condition fails in the core. We check polytropic, bag-model-inspired, and condensate-inspired profiles and the corresponding cosmological reconstruction. Finally, we compute the stationary endpoint's shadow and compare its exterior deformation with published Sagittarius A* measurements. The construction establishes local curvature regularity and marginal-sphere formation, without claiming a microscopic formation mechanism, perturbative stability, or geodesic completeness.

gr-qc