Results 71 to 80 of about 167,096 (220)
Space Weather, Volume 23, Issue 7, July 2025.Abstract Ionospheric scintillation caused by space weather impacts the accuracy and availability of GNSS services and is considered a natural hazard for aviation and other GNSS users. Increased solar activity in 2021–2023, attributed to the ascending phase of the 25th solar cycle, caused an amplification of ionospheric disturbances including the ...
L. Nikitina +4 more
wiley +1 more source
A fast cold-start method of GPS receiver based on satellite orbit prediction
MATEC Web of Conferences, 2018 Time to first fix (TTFF) is one of the crucial indicators to evaluate the performance of a GPS receiver. In this paper, an orbit prediction algorithm to reduce the TTFF of GPS receivers without a network connection is presented.
Yang Ruihong +3 more
doaj +1 more source
Laser Terminals on CubeSats: Developments for Telecommunications and Quantum Links
International Journal of Satellite Communications and Networking, Volume 43, Issue 3, Page 133-146, May/June 2025.ABSTRACT Satellite‐based laser communication is an emerging technology that is finding its way from research to industry. Compared to radio frequency (RF) systems, it has a more efficient size, weight, and power budget and, furthermore, is license free.
Christian Roubal +8 more
wiley +1 more source
Orbital Elements Ephemerides and Interfaces Design of LEO Satellites [PDF]
Journal of Geodesy and Geoinformation Science, 2019 Low earth orbit satellites, with unique advantages, are prosperous types of navigation augmentation satellites for the GNSS satellites constellations. The broadcast ephemeris element needs to be designed as an important index of the augmented LEOs.
Shanchuan FANG,Lan DU,Yunpeng GAO,Peiyuan ZHOU,Zejun LIU
doaj +1 more source
Comprehensive Analyses of PPP-B2b Performance in China and Surrounding Areas
Remote Sensing, 2022 BeiDou Global Navigation Satellite System (BDS-3) provides a regional Precise Point Positioning (PPP) service, called PPP-B2b, for users in China and surrounding areas through B2b signal transmitted from its three geostationary earth orbit (GEO ...
Yan Liu, Cheng Yang, Mengni Zhang
doaj +1 more source
Transit satellite system timing capabilities [PDF]
, 1978 Current time transfer capabilities of the Transit Satellite System are reviewed. Potential improvements in the changes in equipment and operational procedures using operational satellites are ...
Finsod, T. D.
core +1 more source
An Ionospheric Disturbed Index Based on ROTI
Space Weather, Volume 23, Issue 6, June 2025.Abstract The ionosphere has significant impacts on wireless communication, satellite navigation, and space weather. Based on hundreds of global GNSS observation stations, we calculate the rate of TEC index (ROTI). Through the analysis of ROTI, we establish a global ionospheric disturbed index (IDI) to directly characterize ionospheric disturbances ...
Cheng Wang, Xiaoxue Min, Hong Hu
wiley +1 more source
Space Weather, Volume 23, Issue 2, February 2025.Abstract With the onset of solar activities of the 25th solar cycle, ionospheric perturbations have become increasingly frequent, posing significant challenges to various applications of Global Navigation Satellite Systems (GNSS). The Rate of Total Electron Content (TEC) Index (Rate of TEC Index (ROTI)), commonly derived from GNSS data sampled at 30‐s ...
Zhouyu Zhang +6 more
wiley +1 more source
Engineering Reports, Volume 7, Issue 1, January 2025.ABSTRACT Due to the long transmission distance of the constellation network represented by the low‐orbit satellite system, the satellite‐to‐ground link is subject to large path loss and limited communication performance. This paper uses multi‐satellite and multi‐beam joint transmission technology to form a virtual multiplex network with ground multi ...
Yuyang Liu, Tong Shi, Hua Wang
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. +5 more
core +1 more source