Results 91 to 100 of about 1,106,314 (231)

Real-time PPP algorithm considering hourly discontinuous BDS-3 broadcast ephemeris with covariance-adaptive Kalman filter

Satellite Navigation
Previous studies indicate that the accuracy of the BDS-3 broadcast orbit is comparable to that of the real-time precise products provided by International GNSS Service (IGS). However, the precision of both the broadcast orbit and clock remains limited by
Cheng Yang, Kai Wang, Yingnan Zhang, Jiayi Shi, Zhouzheng Gao   +4 more
doaj   +1 more source

Optical Tracking Data Validation and Orbit Estimation for Sparse Observations of Satellites by the OWL-Net

Sensors, 2018
An Optical Wide-field patroL-Network (OWL-Net) has been developed for maintaining Korean low Earth orbit (LEO) satellites’ orbital ephemeris. The OWL-Net consists of five optical tracking stations.
Jin Choi, Jung Hyun Jo, Hong-Suh Yim, Eun-Jung Choi, Sungki Cho, Jang-Hyun Park   +5 more
doaj   +1 more source

Orbital Period Refinement of CoRoT Planets with TESS Observations

Frontiers in Astronomy and Space Sciences, 2021
CoRoT was the first space mission dedicated to exoplanet detection. Operational between 2007 and 2012, this mission discovered 37 transiting planets, including CoRoT-7b, the first terrestrial exoplanet with a measured size. The precision of the published
Peter Klagyivik , Peter Klagyivik , Peter Klagyivik , Hans J. Deeg , Hans J. Deeg , Szilárd Csizmadia , Juan Cabrera , Grzegorz Nowak , Grzegorz Nowak    +8 more
doaj   +1 more source

CNN‐Based Model for 3D CME Parameter Prediction – A Proof of Concept

Journal of Geophysical Research: Machine Learning and Computation, Volume 2, Issue 4, December 2025.
Abstract Accurate 3D reconstruction of coronal mass ejections (CMEs) is essential for understanding their propagation and improving space weather forecasts. In this study, we present a proof‐of‐concept deep learning framework that predicts seven parameters from synthetic multi‐view coronagraph images.
Harshita Gandhi, Huw Morgan, Cory Thomas
wiley   +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

A Next Generation High-speed Data Acquisition System for Multi-channel Infrared and Optical Photometry [PDF]

, 2001
We report the design, operation, and performance of a next generation high-speed data acquisition system for multi-channel infrared and optical photometry based on the modern technologies of Field Programmable Gate Arrays, the Peripheral Component ...
Eikenberry, Stephen S., Moon, Dae-Sik, Pirger, Bruce E.   +2 more
core   +3 more sources

MHD Forecasting of Solar Wind With Coronal Mass Ejections

Space Weather, Volume 23, Issue 12, December 2025.
Abstract We present a model, implemented as an online service, for predicting the speed and density of solar wind in the inner heliosphere and near Earth. The model is based on a numerical magnetohydrodynamics code PLUTO. The inner boundary maps are continuously obtained from the National Centers for Environmental Prediction, where they are updated 1 ...
S. Arutyunyan, A. Kodukov, M. Subbotin, D. Pavlov   +3 more
wiley   +1 more source

Lack of Transit Timing Variations of OGLE-TR-111b: A re-analysis with six new epochs [PDF]

, 2010
We present six new transits of the exoplanet OGLE-TR-111b observed with the Magellan Telescopes in Chile between April 2008 and March 2009. We combine these new transits with five previously published transit epochs for this planet between 2005 and 2006 ...
Ballard, Barnes, Carter, Claret, Coughlin, D. J. Osip, Díaz, E. R. Adams, Ford, Gibson, J. L. Elliot, M. López-Morales, Mandel, Miller-Ricci, Miller-Ricci, Minniti, Miralda-Escudé, S. Seager, Silva, Steffen, Udalski, Winn   +21 more
core   +2 more sources

Premature Reentry of the Binar CubeSats Due To Underestimation of Solar and Geomagnetic Activities and Its Implication for Importance of Medium‐ and Long‐Term Space Weather Forecasts

Space Weather, Volume 23, Issue 12, December 2025.
Abstract The rapid development of low‐Earth orbit (LEO) satellites brings increased attention to spacecraft collisions, space debris, orbital decay, and satellite reentry. Neutral density and associated drag force on the satellite orbits elevate space risks, significantly determined by space weather disturbances, particularly geomagnetic storms.
Xin Wang, Ronglan Wang, Kunpeng Wang, Zhitao Yang, Tingling Ren, Jifeng Cao, Ming Li, Siqing Liu, Bingxian Luo, Chi Wang   +9 more
wiley   +1 more source

INPOP08, a 4-D planetary ephemeris: From asteroid and time-scale computations to ESA Mars Express and Venus Express contributions

, 2009
The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besancon Observatory is presented here. INPOP08 is a 4-dimension ephemeris since it provides to users positions and velocities of planets and the relation ...
A. Fienga, Baer, Baer, Budnik, C. Le Poncin-Lafitte, Damour, Damour, F. Budnik, Fairhead, Fienga, Folkner, H. Manche, Hilton, Irwin, J. Laskar, Klioner, Konopliv, L. Somenzi, M. Gastineau, Michalak, P. Kuchynka, Soffel, Standish, T. Morley, Tedesco   +24 more
core   +4 more sources