Results 111 to 120 of about 38,225 (268)

UAV‐Based Precision Seed Dropping for Automated Reforestation

open access: yesJournal of Field Robotics, EarlyView.
ABSTRACT Wildfires and deforestation pose significant threats to forest ecosystems, motivating scalable methods for reforestation beyond labor‐intensive cultivation of native forest seedlings in nurseries. To enable large‐scale direct seeding of native species, this paper presents the design, analysis, and field evaluation of a UAV‐based seed‐dropping ...
Qi Rui Lee   +5 more
wiley   +1 more source

Digital Twin‐Based Optimization of Service Availability in LEO Mega Constellations Considering Handover Delays in Open RAN

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT As non‐terrestrial networks (NTNs) become integral to future 6G systems, ensuring seamless connectivity and service continuity over low Earth orbit (LEO) satellite constellations is essential. This work investigates the impact of open radio access network (RAN) functional splits on handover performance in NTNs, focusing on minimizing service ...
Siva Satya Sri Ganesh Seeram   +3 more
wiley   +1 more source

Three‐Year Propagation Experiment at Ku‐, Ka‐, and Q‐Band in French West Indies

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT From January 2021 to December 2023, the Office National d'Etudes et de Recherches Aérospatiales (ONERA) and the Centre National d'Etudes Spatiales (CNES) conducted a three‐year Earth‐space propagation measurement campaign in Guadeloupe. The experiment used beacon receivers deployed in Pointe‐à‐Pitre airport to record signals at 11.2, 19.7, and
Jean‐Pascal Monvoisin   +3 more
wiley   +1 more source

Path‐Based Deep Reinforcement Learning for On‐Board Routing in Satellite Constellation Networks

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Efficient usage of available network resources is a crucial factor for broadband services in interconnected satellite constellations. To meet required quality of service standards under heavy network loads, it is essential to optimize traffic distribution among the intersatellite links. To address this challenge, we propose an adaptive traffic
Manuel M. H. Roth   +4 more
wiley   +1 more source

Insights From the Alphasat Aldo Paraboni Experiment at Tito Scalo and Spino d'Adda: Characterizing Scintillation and Rain Attenuation at Ka‐ and Q‐Band Frequencies

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT We present experimental results on the relationship between rain attenuation and simultaneous scintillation during rain events, based on beacon signal measurements at 19.7 (Ka‐band) and 39.4 GHz (Q‐band) from the geosynchronous Alphasat satellite (25° E), received at two Italian ground stations, Spino d'Adda (42.1° slant path) and Tito Scalo ...
Miles Turner   +5 more
wiley   +1 more source

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

BROADCAST TELEVISION: BROADCAST GEOGRAPHY?

open access: yesEuropean Journal of Geography, 2011
Television plays an important role in how the public both understands and takes an interest in geography. As geographers, if we are to maximise the opportunities provided by television to promote geography, we need to understand how it is developing in the 21st century. The first part of this paper examines some of the concepts currently applied to the
openaire   +2 more sources

Directive Antenna Clutter Loss in Slant Paths

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT This paper investigates the development of a clutter loss model specifically for slant paths involving directive antennas. Conventionally, clutter loss is characterized by using isotropic antennas to facilitate standard link budget calculations via single antenna gain values.
Fernando Pérez Fontán   +4 more
wiley   +1 more source

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