Results 41 to 50 of about 163,832 (185)

Izračun položaja GPS-satelita iz podatkov preciznih efimerid : GPS-orbit computation from precise ephemeris data [PDF]

Geodetski Vestnik, 2005
The article describes the theoretical point of view of the GPS precise ephemerides application that should be used in most precise GPS processing. Regarding broadcast, precise ephemerides allow us to achieve a much better accuracy of the final GPS ...
Bojan Stopar, Polona Pavlovčič Prešeren   +1 more
doaj  

Pembuatan Program Ekstraksi Dan Penentuan Posisi Satelit Dari File Navigation Rinex Versi 2.10 [PDF]

, 2015
In positioning using the GPS the first step that we must do is calculating the satellite position during the observation. The precision of a point in a GPS survey is affected by the precision of the satellite position that recorded in the observation ...
Rahmat, V. (Vauzul), Sasmito, B. (Bandi), Yuwono, B. D. (Bambang)   +2 more
core  

A GIVE Prediction Method in SBAS Based on GAT‐TCN

Space Weather, Volume 23, Issue 11, November 2025.
Abstract A Grid Ionospheric Vertical Error (GIVE) prediction model based on GAT‐TCN is proposed in this paper. The model integrates the Graph Attention Network (GAT) with the Temporal Convolutional Network to enhance prediction accuracy while ensuring the integrity of the Satellite‐Based Augmentation System, thereby improving its availability.
Hao Zhang, Yingkui Gong, Fei Zhao, Yuanhang Liu, Cheng Yu, Ziyue Hu, Yubo Zhu, Guang Yang, Hong Yuan   +8 more
wiley   +1 more source

Method and apparatus for autonomous, in-receiver prediction of GNSS ephemerides [PDF]

, 2012
Methods and apparatus for autonomous in-receiver prediction of orbit and clock states of Global Navigation Satellite Systems (GNSS) are described. Only the GNSS broadcast message is used, without need for periodic externally-communicated information ...
Bar-Sever, Yoaz E., Bertiger, William I.
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, M. Ravanelli, A. Bonforte, V. Capparelli, V. Carbone, S. Scollo, L. Mereu, A. Cannata   +7 more
wiley   +1 more source

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, Tong Liu, Zonghua Ding, Jian Liu, Yanshi Huang, Kun Zhang, Shengliang Fang, Shizhong Li, Qinglei Kong, Bo Chen   +9 more
wiley   +1 more source

Representations of Time Coordinates in FITS

, 2014
In a series of three previous papers, formulation and specifics of the representation of World Coordinate Transformations in FITS data have been presented. This fourth paper deals with encoding time.
Allen, Steven L., Bunclark, Peter S., Calabretta, Mark R., Manchester, Richard N., Rots, Arnold H., Thompson, William T.   +5 more
core   +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

LOBEFIT: LEO satellite broadcast ephemeris fitting open-source software based on automatic differentiation technique

SoftwareX
LEO (Low Earth Orbit)-based PNT (Positioning, Navigation and Timing) has become a research topic of much interest and a focus of development. As LEO satellites for PNT are expected to independently provide space-time references in the future, similar to ...
Zhao Xi, Yu Baoguo, Luo Bin
doaj   +1 more source

Performance Evaluation of the Dual‐Frequency Ionospheric Free Combination on BDS‐3 Single Point Positioning Accuracy

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