Results 31 to 40 of about 4,598 (208)

An influence of the covariance between single orbit parameters on the accuracy of observations of the pseudo-ranges and phase differences

Metrology and Measurement Systems, 2020
The possibilities to improve values of the satellite orbit elements by employing the pseudo-ranges and differences of carrier phase frequencies measured at many reference GPS stations are analysed. An improvement of orbit ephemeris is achieved by solving
Skeivalas Jonas, Paršeliūnas Eimuntas, Putrimas Raimundas, Šlikas Dominykas   +3 more
doaj   +1 more source

Broadcast Ephemeris with Centimetric Accuracy: Test Results for GPS, Galileo, Beidou and Glonass

Remote Sensing, 2021
Here we test the capability of the Broadcast Ephemeris Message, in both its GPS-like (Keplerian ellipse with secular and periodic perturbations) and Glonass-like (numerical integration of a 9D state vector) formats, to reproduce a corresponding precise ...
Alessandro Caporali, Joaquin Zurutuza
doaj   +1 more source

Performance Assessment of Non-Integer-Hour Data Blocks in BDS Broadcast Ephemeris

IEEE Access
Due to system anomalies, BeiDou navigation satellite system (BDS) sometimes updates the broadcast ephemeris at non-integral hours. The gross errors contained in the non-integer-hour data blocks of broadcast ephemeris will lead to the signal-in-space (SIS)
Jingjing Wang, Chao Zhou
doaj   +1 more source

Performance of Multi-GNSS in the Asia-Pacific Region: Signal Quality, Broadcast Ephemeris and Precise Point Positioning (PPP)

Remote Sensing, 2022
Since BeiDou Navigation Satellite System (BDS) and Japan’s Quasi-Zenith Satellite System (QZSS) have more visible satellites in the Asia-Pacific region, and navigation satellites of Global Positioning System (GPS), Galileo satellite navigation system ...
Mengyuan Li, Guanwen Huang, Le Wang, Wei Xie, Fan Yue   +4 more
doaj   +1 more source

At the far end of everything: A likely Ahrensburgian presence in the far north of the Isle of Skye, Scotland

Journal of Quaternary Science, EarlyView.
ABSTRACT A Late Upper Paleolithic (LUP) site containing Ahrensburgian‐type stone tools has been discovered at South Cuidrach, Isle of Skye, Scotland. Together with a group of intertidal stone circular alignments also recently discovered on the island, this new evidence for the occupation of northern Scotland also represents the most northerly LUP site ...
Karen Hardy, Natasha L.M. Barlow, Edward Taylor, Sarah L. Bradley, John McCarthy, Graham Rush   +5 more
wiley   +1 more source

An exploration of market mechanisms to the wicked problem of space debris 太空垃圾棘手问题的市场机制探究 Una exploración de los mecanismos del mercado para resolver el complejo problema de los desechos espaciales

Risk, Hazards &Crisis in Public Policy, EarlyView.
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, Maureen Mayala, Faith Victoria Ni   +2 more
wiley   +1 more source

The fettered and the flea: a new poem by Edmund Waller☆

Renaissance Studies, EarlyView.
Abstract This contribution explores for the first time a 22‐line poem in a British Library manuscript, ‘To a young lady that kept a flea chay'nd in a box’, which can be convincingly ascribed to Edmund Waller. Its most famous relative is Donne's ‘The Flea’, but its ancestry differs.
Stuart Gillespie
wiley   +1 more source

Observed Latitudinal, Longitudinal and Temporal Variability of Io's Atmosphere Simulated by a Purely Sublimation Driven Atmosphere

Journal of Geophysical Research: Planets, Volume 130, Issue 7, July 2025.
Abstract How much of Io's SO2 ${\text{SO}}_{2}$ atmosphere is driven by volcanic outgassing or sublimation of SO2 ${\text{SO}}_{2}$ surface frost is a question with a considerable history. We develop a time dependent surface temperature model including thermal inertia and the exact celestial geometry to model the radiation driven global structure and ...
A.‐C. Dott, J. Saur, S. Schlegel, D. F. Strobel, K. de Kleer, I. de Pater   +5 more
wiley   +1 more source

Comprehensive Comparisons of Satellite Data, Signals, and Measurements between the BeiDou Navigation Satellite System and the Global Positioning System

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

Study on systematic errors of BDS-3 broadcast ephemeris and their effects with Helmert transformation

Satellite Navigation, 2023
Previous studies have not evaluated the systematic errors implied in the third generation of BeiDou-3 Navigation Satellite System (BDS-3) broadcast ephemeris.
Min Li, Jiangnan Zhang, Guo Chen, Liang Chen, Qile Zhao   +4 more
doaj   +1 more source