Results 21 to 30 of about 107,844 (297)

A critical approach to the concept of a polar, low-altitude LARES satellite [PDF]

, 2002
According to very recent developments of the LARES mission, which would be devoted to the measurement of the general relativistic Lense--Thirring effect in the gravitational field of the Earth with Satellite Laser Ranging, it seems that the LARES ...
Ciufolini I, Ciufolini I, Iorio L, Iorio L, Iorio L, Kaula W M, Lemoine F G, Lense J, Lorenzo Iorio, Lucchesi D, Lucchesi D   +10 more
core   +3 more sources

Review of the Development of Low Earth Orbit Satellite Communication for Smart High-Speed Railway

天地一体化信息网络, 2023
Low-earth orbit satellites have the advantages of wide bandwidth, low latency, and large coverage, making them very suitable as a supplement to ground cellular networks.Low-earth orbit satellites can meet the requirements of smart high-speed railway full
Zhaoyang SU, Liu LIU, Jiachi ZHANG, Tao ZHOU, Wei LIN, Yiqun LIANG   +5 more
doaj   +2 more sources

Extension of the sun-synchronous Orbit [PDF]

, 2010
Through careful consideration of the orbit perturbation force due to the oblate nature of the primary body a secular variation of the ascending node angle of a near-polar orbit can be induced without expulsion of propellant.
Betts J. T., Duesmann B., François Bosquillon de Frescheville, Frerick J., Malcolm Macdonald, Massimiliano Vasile, McKay R., Robert McKay, Roy A. E., Vallado D. A., Vasile M., Vasile M., Wallace N.   +12 more
core   +1 more source

Joint optimization based satellite handover strategy for low earth orbit satellite networks

IET Communications, 2021
Low earth orbit constellation satellite communication has the characteristics of low propagation delay, low path loss, low launch cost and wide range of applications.
Yifei Liu, Lang Feng, Liang Wu, Zaichen Zhang, Jian Dang, Bingcheng Zhu, Lei Wang   +6 more
doaj   +1 more source

Routing optimization based on topology control in satellite network

Tongxin xuebao, 2018
A new double-layer satellite network model for space networking was established and a routing algorithm based on topology control (TCRA) was proposed considering the advantages of low earth orbit and stationary earth orbit satellite networks.This model ...
Xiaogang QI, Jiulong MA, Lifang LIU
doaj   +2 more sources

Analytic Model for Low Earth Orbit Satellite Solar Power

IEEE Transactions on Aerospace and Electronic Systems, 2020
An analytic model for calculating the instantaneous and average orbital power available to a satellite in a circular low Earth orbit is presented. By accounting for the effects of angle of solar incidence and eclipsing, for both stabilized and tumbling satellites, this model allows for fast, simple, accurate calculations of available power without the ...
Grey, John Petrus, Mann, Ian R., Fleischauer, Michael D., Elliott, Duncan G.   +3 more
openaire   +1 more source

Handover Solutions for 5G Low-Earth Orbit Satellite Networks

IEEE Access, 2022
Low-Earth orbit (LEO) satellite networks are meant to be fundamental to closing the digital divide, enabling new market opportunities and providing fifth-generation (5G) New Radio (NR) connectivity everywhere at any time.
Enric Juan, Mads Lauridsen, Jeroen Wigard, Preben Mogensen   +3 more
doaj   +1 more source

Fluid Biomarkers of Disease Burden and Cognitive Dysfunction in Progressive Supranuclear Palsy

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Identifying objective biomarkers for progressive supranuclear palsy (PSP) is crucial to improving diagnosis and establishing clinical trial and treatment endpoints. This study evaluated fluid biomarkers in PSP versus controls and their associations with regional 18F‐PI‐2620 tau‐PET, clinical, and cognitive outcomes.
Roxane Dilcher, Charles B. Malpas, Stuart J. McDonald, William T. O’Brien, Craig Despott, Kelly L. Bertram, Matthew P. Pase, Lukas Frontzkowski, Meng Law, Terence J. O’Brien, Lucy Vivash   +10 more
wiley   +1 more source

Sustainability assessment of Low Earth Orbit (LEO) satellite broadband mega-constellations

, 2023
Abstract The growth of mega-constellations is rapidly increasing the number of rocket launches required to place new satellites in space. While Low Earth Orbit (LEO) broadband satellites help to connect unconnected communities and achieve the Sustainable Development Goals, there are also a range of negative environmental externalities, from the
Edward Oughton, Bonface Osoro, Andrew Wilson, Akhil Rao   +3 more
openaire   +2 more sources

Baseline Regional Cholinergic Denervation Predicts Cognitive Trajectories in Moderate Parkinson Disease

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Cognitive decline is a disabling and variable feature of Parkinson disease (PD). While cholinergic system degeneration is linked to cognitive impairments in PD, most prior research reported cross‐sectional associations. We aimed to fill this gap by investigating whether baseline regional cerebral vesicular acetylcholine transporter ...
Taylor Brown, Giulia Carli, Prabesh Kanel, Stiven Roytman, Jaimie Barr, Nicolaas I. Bohnen, Roger L. Albin   +6 more
wiley   +1 more source