Results 61 to 70 of about 167,096 (220)
The Future of Time: UTC and the Leap Second
, 2011 Before atomic timekeeping, clocks were set to the skies. But starting in 1972, radio signals began broadcasting atomic seconds and leap seconds have occasionally been added to that stream of atomic seconds to keep the signals synchronized with the actual
Allen, Steve +4 more
core +1 more source
Ionospheric Delays Compensation for On-The-Fly Integer Ambiguity Resolution in Long Baseline LEO Formations [PDF]
, 2014 This paper deals with the real-time onboard accurate relative positioning by Carrier-phase Differential GPS (CDGPS) of LEO formations with baselines of hundreds of kilometers.
Tancredi, Urbano
core +1 more source
Ionospheric Disturbances During the 4 December 2015, Mt. Etna Eruption
Earth and Space Science, Volume 12, Issue 10, October 2025.Abstract This study presents the detection and characterization of co‐volcanic ionospheric disturbances (CVIDs) associated with Mt. Etna's large‐scale lava fountain (Italy). Leveraging a dense and proximal GNSS network, we identify local Total Electron Content (TEC) perturbations extending up to ∼ ${\sim} $200 km south/southwest of the vent.
F. Ferrara +7 more
wiley +1 more source
Impacts of Satellite Orbit and Clock on Real-Time GPS Point and Relative Positioning
Sensors, 2017 Satellite orbit and clock corrections are always treated as known quantities in GPS positioning models. Therefore, any error in the satellite orbit and clock products will probably cause significant consequences for GPS positioning, especially for real ...
Junbo Shi +3 more
doaj +1 more source
Phoenix-XNS - A Miniature Real-Time Navigation System for LEO Satellites [PDF]
, 2006 The paper describes the development of a miniature GPS receiver with integrated real-time navigation system for orbit determination of satellites in low Earth orbit (LEO).
Gill, Eberhard, Montenbruck, Oliver
core
Real‐Time Regional Ionosphere Modeling With RFR‐Net Over China
Space Weather, Volume 23, Issue 8, August 2025.Abstract The mid‐to‐low‐latitude ionosphere, influenced by phenomena such as the Equatorial Ionization Anomaly, responds more sensitively to changes in solar activity, which negatively affect the transmission of various electromagnetic signals. Moreover, next‐generation technologies, particularly Precise Point Positioning‐Real‐Time Kinematic (PPP‐RTK),
Mengfei Sun +9 more
wiley +1 more source
Izračun položaja GPS-satelita iz podatkov oddanih efemerid : GPS-Orbit Computation from Broadcast Ephemeris Data [PDF]
Geodetski Vestnik, 2004 The article describes the theoretical point of view of the GPS-broadcast ephemerides application. Beside the raw GPS observations, any kind of GPS ephemerides represents indispensable data in the GPS processing engine.
Bojan Stopar +1 more
doaj
Accurate and Rapid Broadcast Ephemerides for Beidou-Maneuvered Satellites
Remote Sensing, 2019 The geostationary earth orbit (GEO) and inclined geosynchronous orbit (IGSO) satellites of the Beidou navigation satellite system are maneuvered frequently. The broadcast ephemeris can be interrupted for several hours after the maneuver.
Jing Qiao +3 more
doaj +1 more source
The Benefit of Space Clocks for the Deep Space Network
Radio Science, Volume 60, Issue 8, August 2025.Abstract Ground‐based atomic clocks have been the foundation of the Deep Space Network's (DSN's) ability to provide high‐precision tracking to deep space users for navigation and radio science since its inception in the mid‐1960s. This paper describes the development of space clocks that could aid the DSN and the solar system exploration enterprise ...
T. Ely, E. Burt, K. Cheung, R. Tjoelker
wiley +1 more source
Engineering Reports, Volume 7, Issue 7, July 2025.Some stations have slightly larger errors in mid low latitude regions, while others have slightly smaller errors in high latitude regions. By comparing the B1C/B2a and B2b/B3I IFC SPP results of all 84 stations, it was found that the RMSE of all stations with B2b/B3I IFC was greater than that of B1C/B2a. ABSTRACT This article analyzes the BDS Phase III
Xingli Sun, Jinjie Yao
wiley +1 more source