Results 21 to 30 of about 2,401,485 (384)
Satellite Navigation, 2020 The BeiDou system (BDS) plays a significant role in people’s lives, but its security is easily affected by spoofing attacks. The radio determination satellite service (RDSS) is a special service of BDS that provides two-way communication, positioning ...
Fei Wang +4 more
doaj +1 more source
BOC Signal Acquisition Algorithm Based on Similar Enfoldment
International Journal of Aerospace Engineering, 2020 A BOC signal has been widely used in the Global Navigation Satellite System (GNSS). Although the BOC signal has many advantages, the autocorrelation function (ACF) of the BOC signal has lots of peaks, which makes signal acquisition difficult.
Qi Han +5 more
doaj +1 more source
Nature Communications, 2020 Accurate and comprehensive measurements of economic well-being are fundamental inputs into both research and policy, but such measures are unavailable at a local level in many parts of the world. Here we train deep learning models to predict survey-based
Christopher Yeh +7 more
semanticscholar +1 more source
The Low Earth Orbit Satellite Population and Impacts of the SpaceX Starlink Constellation [PDF]
Astrophysical Journal, 2020 I discuss the current low Earth orbit artificial satellite population and show that the proposed “megaconstellation” of circa 12,000 Starlink Internet satellites would dominate the lower part of the Earth orbit, below 600 km, with a latitude-dependent ...
J. McDowell
semanticscholar +1 more source
Satellite RNAs and Satellite Viruses [PDF]
Molecular Plant-Microbe Interactions®, 2016 Satellite RNAs and satellite viruses are extraviral components that can affect either the pathogenicity, the accumulation, or both of their associated viruses while themselves being dependent on the associated viruses as helper viruses for their infection. Most of these satellite RNAs are noncoding RNAs, and in many cases, have been shown to alter the
openaire +3 more sources
Equivariant filtering framework for inertial-integrated navigation
Satellite Navigation, 2021 This paper proposes an Equivariant Filtering (EqF) framework for the inertial-integrated state estimation. As the kinematic system of the inertial-integrated navigation can be naturally modeled on the matrix Lie group SE 2(3), the symmetry of the Lie ...
Yarong Luo, Chi Guo, Jingnan Liu
doaj +1 more source
Minimum thrust levels for spinning drag-free satellites = Niveaux minimums de la force motrice pour des satellites rotatoires sans résistance = Minimum triebkraftniveaus für rotierende wiederstandsfreie satelliten [PDF]
, 1975 A drag-free satellite, which contains an internal unsupported proof mass, is shielded from external forces such as solar pressure. Thrustors force the satellite to follow the proof mass and hence the satellite follows an almost purely gravitational orbit.
Olsder, Geert Jan, Powell, J. David
core +2 more sources
Real-time integrity monitoring for a wide area precise positioning system
Satellite Navigation, 2020 The wide area precise positioning system (WAPPS) is a high-precision positioning system based on a global navigation satellite system. Using a GEO satellite or a communication network, it provides users, in its service area, with real-time satellite ...
Yuechen Wang, Jun Shen
doaj +1 more source
, 2022 The fifth generation (5G) Wireless Communication systems development has brought out a paradigm shift using advanced technologies e.g., softwarization, virtualization, Massive MIMO, ultra-densification and introduction of new frequency bands. However, as the societal needs grow, and to satisfy UN's Sustainable Development Goals (SDGs), 6G and beyond ...
Kota, Sastri +34 more
openaire +6 more sources
PPP models and performances from single- to quad-frequency BDS observations
Satellite Navigation, 2020 Nowadays, China BeiDou Navigation Satellite System (BDS) has been developed well and provided global services with highly precise positioning, navigation and timing (PNT) as well as unique short-message communication, particularly global system (BDS-3 ...
Shuanggen Jin, Ke Su
doaj +1 more source