Results 1 to 10 of about 20,201 (263)
Astrometric observations of Phobos and Deimos during the 1971 opposition of Mars [PDF]
A&A 572, A104 (2014), 2015 Accurate positional measurements of planets and satellites are used to improve our knowledge of their dynamics and to infer the accuracy of planet and satellite ephemerides. In the framework of the FP7 ESPaCE project, we provide the positions of Mars, Phobos, and Deimos taken with the U.S.
Arlot, J. -E. +6 more
arxiv +24 more sources
Pulsar Timing with the Parkes Radio Telescope for the Fermi Mission [PDF]
, 2009 We report here on two years of timing of 168 pulsars using the Parkes radio telescope. The vast majority of these pulsars have spin-down luminosities in excess of 10^34 erg/s and are prime target candidates to be detected in gamma-rays by the Fermi Gamma-Ray Space Telescope.
A. Possenti +22 more
arxiv +3 more sources
Securing the legacy of TESS through the care and maintenance of TESS planet ephemerides [PDF]
, 2019 Much of the science from the exoplanets detected by the TESS mission relies on precisely predicted transit times that are needed for many follow-up characterization studies. We investigate ephemeris deterioration for simulated TESS planets and find that the ephemerides of 81% of those will have expired (i.e.
Barclay, Thomas +18 more
arxiv +5 more sources
Gravity tests with INPOP planetary ephemerides [PDF]
, 2009 In this paper, we present several gravity tests made in using the last INPOP08 planetary ephemerides. We first propose two methods to estimate the PPN parameter $\beta$ and its correlated value, the Sun J2 and we discuss the correlation between the Sun J2 and the mass of the asteroid ring. We estimate possible advance in the planet perihelia.
A. Fienga +9 more
arxiv +4 more sources
ASSESSING EFFICIENCY OF GPS EPHEMERIDES IN DIFFERENT REGION USING PRECISE POINT POSITIONING [PDF]
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2023 Precise Point Positioning (PPP) is a technique that process Global Positioning System (GPS) observation that can achieve sub-decimetre accuracy. Precise ephemerides that contain satellite clock and position plays a vital role in minimising orbital and ...
H. S. Lee +3 more
doaj +1 more source
Newly found Mayan records of astronomical phenomena in Dresden Codex [PDF]
Serbian Astronomical Journal, 2023 The rich culture of old Maya gave birth to a very complicated and complex calendar; they also recorded important historical events and many significant astronomical phenomena.
Vondrák J., Böhm V., Böhm B.
doaj +1 more source
Implementation of the variation of the luni-solar acceleration into GLONASS orbit calculus [PDF]
Geodetski Vestnik, 2021 In the differential equation system describes the motion of GLONASS satellites (rus. Globalnaya Navigazionnaya Sputnikovaya Sistema, or Global Navigation Satellite System ), the acceleration caused by the luni-solar traction is often taken as a constant ...
Sid Ahmed Medjahed +3 more
doaj +1 more source
AGG+, 2021 This paper analyses how broadcast and precise ephemerides in alignment, using the least-squares method, affect the accuracy of coordinates of the newly included permanent stations.
Tanja Đukanović +2 more
doaj +1 more source
Effect of using different satellite ephemerides on GPS PPP and post processing techniques
Geodesy and Cartography, 2021 The orbital error is one of the errors in GPS which affect the accuracy of GPS positioning. In this research GPS broadcast, ultra-rapid, rapid and precise satellite ephemerides are used for processing different baseline lengths among some CORS stations ...
Khaled Mahmoud Abdel Aziz +1 more
doaj +1 more source
Did old Maya observe Mercury? [PDF]
Serbian Astronomical Journal, 2022 It is well known that the rich culture of old Maya contained, among other, also a very complicated and complex calendar, in which they recorded not only historical events, but also significant astronomical phenomena.
Vondrák J., Böhm V., Böhm B.
doaj +1 more source