Results 31 to 40 of about 19,555 (207)

Investigating Performance of BDS-2+3 Dual-Frequency Absolute Positioning With Broadcast Ephemerides, RTS and Final MGEX Products

open access: yesIEEE Access, 2023
BDS-3 was formally put into service on July 31, 2020, and now along with BDS-2 provides the positioning, navigation and timing services. In this contribution, different techniques of dual-frequency absolute positioning using the fully serviceable BDS-2 ...
Shengnan Liu, Shaolin Zhu, Jian Zhang
doaj   +1 more source

INPOP new release: INPOP13b [PDF]

open access: yes, 2015
Based on the use of MESSENGER radiotracking data in the construction of new Mercury ephemerides (Verma et al. 2014) a new planetary ephemerides INPOP13b was built including Mercury improvements but also improvements on the Mars orbit and on the tie of ...
Fienga, A.   +4 more
core  

Gravity tests with INPOP planetary ephemerides

open access: yes, 2009
In this paper, we present several gravity tests made in using the last INPOP08 planetary ephemerides. We first propose two methods to estimate the PPN parameter $\beta$ and its correlated value, the Sun J2 and we discuss the correlation between the Sun ...
A. Fienga   +9 more
core   +3 more sources

Low‐Complexity Hybrid Beamforming for LEO Satellites: Beam Update Rate Analysis and Advanced Adaptive Precoding

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Low Earth Orbit (LEO) satellite constellations offer unprecedented opportunities for global broadband connectivity but pose significant beamforming challenges due to rapid platform motion and stringent onboard hardware constraints. Fully digital architectures, while optimal in theory, remain impractical for satellite payloads, motivating ...
Mohammad Momani   +2 more
wiley   +1 more source

Maya records of planetary conjunctions in Dresden Codex [PDF]

open access: yesSerbian Astronomical Journal
Old Mayas designed a very complicated calendar, and they also recorded important historical events and astronomical phenomena. Dresden Codex (DC), one of the four preserved Mayan hieroglyphic literal legacies, contains many of these, covering ...
Vondrák J., Böhm V., Böhm B.
doaj   +1 more source

Orbital Period Refinement of CoRoT Planets with TESS Observations

open access: yesFrontiers in Astronomy and Space Sciences, 2021
CoRoT was the first space mission dedicated to exoplanet detection. Operational between 2007 and 2012, this mission discovered 37 transiting planets, including CoRoT-7b, the first terrestrial exoplanet with a measured size. The precision of the published
Peter Klagyivik    +8 more
doaj   +1 more source

A Java Program Generating Barycentric Observer Velocities from JPL Ephemerides

open access: yes, 2022
This works presents a program which computes velocities of an Earth-bound observatory in the reference frame of the barycenter of the solar system. It feeds from ephemerides files of the Jet Propulsion Laboratory to extract the velocity of the geocenter,
Mathar, Richard J.
core  

City of God and the Duty of Just Memory

open access: yesModern Theology, EarlyView.
Abstract In a recent essay, Richard Miller claims that Augustine presumes a duty to remember justly in his City of God. However, Miller's brief reference to a presumed duty of “just memory” does not fully explain how Augustine conceptualizes this duty or how it relates to his theological concerns.
Zachary J. Taylor
wiley   +1 more source

Tests of General relativity with planetary orbits and Monte Carlo simulations

open access: yes, 2014
Based on the new developped planetary ephemerides INPOP13c, determinations of acceptable intervals of General Relativity violation in considering simultaneously the PPN parameters $\beta$, PPN $\gamma$, the flattening of the sun $J_{2}^\odot$ and time ...
Exertier, P.   +4 more
core   +3 more sources

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