Results 31 to 40 of about 143,499 (172)
A 16-parameter GEO Broadcast Ephemeris [PDF]
Journal of Geodesy and Geoinformation Science, 2018 Currently, the broadcast ephemerides used in GEOs are same as those of the MEOs and IGSOs in the BeiDou navigation constellation. However, a trade-off strategy, i.e.
Zhongkai ZHANG,Lan DU,Li LIU,Feng HE,Yu LU,Peiyuan ZHOU
doaj
Assessing Real-Time PPP Performance for PWV Estimation Using Low-Cost GNSS Stations and Multi-Source Correction Products [PDF]
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information SciencesMonitoring atmospheric water vapour is essential for weather forecasting and climate studies. GNSS networks can retrieve Precipitable Water Vapour (PWV) continuously at each station location, but the accuracy depends on the quality of the satellite orbit
M. Bagheri, P. Dabove
doaj +1 more source
Impact of the Initial State on BDS Real-Time Orbit Determination Filter Convergence
Remote Sensing, 2018 High precision real-time orbit of navigation satellites are usually predicted based on batch estimation solutions, which is highly dependent on the accuracy of the dynamic model.
Yun Qing +4 more
doaj +1 more source
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
On the performance of broadcast algorithms in interconnection networks [PDF]
, 2005 Broadcast Communication is among the most primitive collective capabilities of any message passing network. Broadcast algorithms for the mesh have been widely reported in the literature.
Ould-Khaoua, M. +3 more
core +1 more source
Izračun položaja GPS-satelita iz podatkov preciznih efimerid : GPS-orbit computation from precise ephemeris data [PDF]
Geodetski Vestnik, 2005 The article describes the theoretical point of view of the GPS precise ephemerides application that should be used in most precise GPS processing. Regarding broadcast, precise ephemerides allow us to achieve a much better accuracy of the final GPS ...
Bojan Stopar +1 more
doaj
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
A comparison of GPS broadcast and DMA precise ephemerides [PDF]
, 1994 We compare the broadcast ephemerides from Global Positioning Satellites (GPS) to the postprocessed ephemerides from the Defense Mapping Agency (DMA). We find significant energy in the spectrum of the residuals at 1 cycle/day and higher multiples.
Shattil, Steve +2 more
core
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