Results 51 to 60 of about 164,653 (221)

Performance Analysis of BDS-3 SAIM and Enhancement Research on Autonomous Satellite Ephemeris Monitoring

Remote Sensing, 2022
Integrity is one of the key indicators used to characterize the performance of the global navigation satellite systems (GNSSs) and is closely related to user safety.
Lei Chen, Yongshan Dai, Weiguang Gao, Yueling Cao, Zhigang Hu, Qianyi Ren, Xin Nie, Jiaju Zheng, Ruiqiang Shao, Ling Pei, Lu Wang   +10 more
doaj   +1 more source

A Real-Time Robust Method to Detect BeiDou GEO/IGSO Orbital Maneuvers

Sensors, 2017
The frequent maneuvering of BeiDou Geostationary Orbit (GEO) and Inclined Geosynchronous Orbit (IGSO) satellites affects the availability of real-time orbit, and decreases the accuracy and performance of positioning, navigation and time (PNT) services ...
Guanwen Huang, Zhiwei Qin, Qin Zhang, Le Wang, Xingyuan Yan, Lihong Fan, Xiaolei Wang   +6 more
doaj   +1 more source

Calibration and Impact of BeiDou Satellite-Dependent Timing Group Delay Bias

Remote Sensing, 2020
The accuracy of the timing group delay (TGD) transmitted in the broadcast ephemeris is an important factor that affects the service performance of a GNSS system.
Yize Zhang, Hu Wang, Junping Chen, Ahao Wang, Lingdong Meng, Ershen Wang   +5 more
doaj   +1 more source

Galileo Single Point Positioning Assessment Including FOC Satellites in Eccentric Orbits

Remote Sensing, 2019
On August 2016, the Milena (E14) and Doresa (E18) satellites started to broadcast ephemeris in navigation message for testing purposes. As the Galileo constellation is not yet complete. It is very important to have two more satellites available since the
Umberto Robustelli, Giovanni Pugliano
doaj   +1 more source

LEO Onboard Real-Time Orbit Determination Using GPS/BDS Data with an Optimal Stochastic Model

Remote Sensing, 2020
The advancements of Earth observations, remote sensing, communications and navigation augmentation based on low Earth orbit (LEO) platforms present strong requirements for accurate, real-time and autonomous navigation of LEO satellites.
Xuewen Gong, Jizhang Sang, Fuhong Wang, Xingxing Li   +3 more
doaj   +1 more source

Analysis of Factors Affecting Asynchronous RTK Positioning with GNSS Signals

Remote Sensing, 2019
For short baseline real-time kinematic (RTK) positioning, the atmosphere and broadcast ephemeris errors can be usually eliminated in double-differenced (DD) processing for synchronous observations.
Bao Shu, Hui Liu, Yanming Feng, Longwei Xu, Chuang Qian, Zhixin Yang   +5 more
doaj   +1 more source

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, Finkleman, David, Seago, John, Seaman, Rob, Seidelmann, P. Kenneth   +4 more
core   +1 more source

Real-Time Precise Orbit Determination of Low Earth Orbit Satellites Based on GPS and BDS-3 PPP B2b Service

Remote Sensing
This study investigates and verifies the feasibility of the precise point positioning (PPP)-B2b enhanced real-time (RT) precise orbit determination (POD) of low Earth orbit (LEO) satellites.
Yali Shi, Tianhe Xu, Min Li, Kai Wei, Shuai Wang, Dixing Wang   +5 more
doaj   +1 more source

A Flexible Ephemeris Representation for GNSS and Alternative PNT Signal Sources Using B-Splines

Navigation, 2023
Most global navigation satellite systems (GNSSs) ephemeris representations require straightforward, albeit specialized algorithms to compute the transmitter position at a time of interest.
Mikaela Dobbin, Penina Axelrad
doaj   +1 more source

Satellite Ephemeris Parameterization Methods to Support Lunar Positioning, Navigation, and Timing Services

Navigation
Plans to establish a satellite network around the Moon to support communication, position, navigation, and timing services are rapidly evolving. Satellites that are part of this system broadcast their ephemeris as finite parameters to lunar users for ...
Marta Cortinovis, Keidai Iiyama, Grace Gao   +2 more
doaj   +1 more source