Results 71 to 80 of about 43,513 (282)
Spitzer Observations of GX17+2: Confirmation of a Periodic Synchrotron Source [PDF]
, 2011 GX17+2 is a low-mass X-ray binary (LMXB) that is also a member of a small family of LMXBs known as "Z-sources" that are believed to have persistent X-ray luminosities that are very close to the Eddington limit. GX17+2 is highly variable at both radio and
Bornak, Jillian +6 more
core +1 more source
Impacts of the May 2024 Extreme Geomagnetic Storm on Global High‐Accuracy GPS Positioning Solutions
Space Weather, Volume 23, Issue 10, October 2025.Abstract The May 2024 geomagnetic storm has been recognized as the most severe one in the past two decades and was categorized as an “extreme” (G5) event according to the NOAA space weather scales. This study applies Precise Point Positioning (PPP) software PRIDE PPP‐AR to over 5,800 worldwide GNSS receiver data to highlight the vulnerability of high ...
Zhe Yang, Y. T. Jade Morton
wiley +1 more source
Sensors, 2016 The Chinese BeiDou navigation satellite system (BDS) aims to provide global positioning service by 2020. The combined use of BDS and Global Positioning System (GPS) is proposed to provide navigation service with more stringent requirements.
Shau-Shiun Jan, An-Lin Tao
doaj +1 more source
Searching for gravitational waves from the Crab pulsar - the problem of timing noise [PDF]
, 2003 Of the current known pulsars, the Crab pulsar (B0531+21) is one of the most promising sources of gravitational waves. The relatively large timing noise of the Crab causes its phase evolution to depart from a simple spin-down model.
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core +3 more sources
Risk, Hazards &Crisis in Public Policy, Volume 16, Issue 3, September 2025.Abstract Near‐earth orbits are becoming congested because of a rapid growth in the number of satellites and space debris, which presents a real threat to the sustainable use of space and the safety of the Earth. Despite space scientists and public policymakers having been actively seeking solutions for decades, solving the problem has been put off ...
Anna Ya Ni +2 more
wiley +1 more source
Remote SensingThis 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 +5 more
doaj +1 more source
Earth and Space Science, Volume 12, Issue 9, September 2025.Abstract The Global Navigation Satellite System (GNSS) real‐time Precise Point Positioning (PPP) technology offers a highly efficient approach for atmospheric Precipitable Water Vapor (PWV) monitoring and extreme weather warning. However, its retrieval accuracy is limited by the performance of orbit and clock products, as well as the coupling effects ...
Wenliang Gao +4 more
wiley +1 more source
Sensors, 2014 More and more Global Navigation Satellite Systems (GNSSs) have been developed and are in operation. Before integrating information on various GNSSs, the differences between the various systems must be studied first. This research focuses on analyzing the
Shau-Shiun Jan, An-Lin Tao
doaj +1 more source
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 +10 more
doaj +1 more source
, 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 +24 more
core +3 more sources