Results 31 to 40 of about 5,627 (172)
International 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
SMTC Configuration and Window Adjustment Strategies for Beam Hopping in NR‐NTN
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT Beam hopping is an effective transmission strategy for nonterrestrial networks (NTNs), enabling satellites to allocate limited power and spectrum resources across different geographical regions over time. However, in NR‐based NTN systems, beam hopping complicates synchronization monitoring because synchronization signal block (SSB) arrivals ...
Hee Wook Kim, Kyungrak Lee, Joon Gyu Ryu
wiley +1 more source
Orbital Period Refinement of CoRoT Planets with TESS Observations
Frontiers 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
Routing and Downlink Resource Allocation for Multicast Traffic in LEO Satellite Constellations
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT In this work, we optimize unicast and multicast traffic delivery over non‐terrestrial networks (NTNs) to users on the ground through direct satellite downlink (DL). We consider a gateway‐free mesh architecture with low Earth orbit (LEO) satellites interconnected via inter‐satellite links (ISLs), where unicast and multicast services compete for
Federico Lozano‐Cuadra +3 more
wiley +1 more source
Long‐Term Propagation Measurements in Madrid in a Q‐Band Satellite‐to‐Earth Link
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT The Q/V band (40/50 GHz) is gaining interest as satellite operators will need larger bandwidth to be able to provide their services, which are experiencing an increasingly high demand. An accurate characterization of the satellite‐to‐Earth propagation channel is of paramount importance to guarantee a high level of quality of service, by ...
Domingo Pimienta‐del‐Valle +3 more
wiley +1 more source
Open Astronomy, 2015 We cast a retrospective look at the mankind’s acquaintance with minor bodies of the Solar System, at the explosive growth in their discoveries resulting from the technological progress, and at gradual understanding of the danger to our very existence ...
Rykhlova L., Bakanas E.
doaj +1 more source
City of God and the Duty of Just Memory
Modern 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
CALCULATION OF EPHEMERIDES FROM INITIAL VALUES [PDF]
, 1962 Calculation of ephemerides of planets and comets from initial ...
Stumpff, K.
core
Constraining exotrojans in hot-Jupiter systems using transit timing variation observations from TESS
Astronomy & AstrophysicsContext. Co-orbital objects, also known as Trojans, are celestial bodies that share a 1:1 mean motion resonance orbit with a planet. Many planets in our Solar System hold Trojans, yet none has been confirmed in exoplanetary systems.
Zhang Zixin +10 more
doaj +1 more source
Renaissance Studies, EarlyView.ABSTRACT Seventeenth‐century virtuosi often figured themselves as epistemic weeders, grubbing up rank thickets of accumulated error. In this article, I argue that these metaphors were unnerved by the shifting status of weeds—ostensibly unwanted plants from the margins of cultivated space, unploughed land or the disturbed soils between growing crops—in ...
Francis Taylor
wiley +1 more source