Results 21 to 30 of about 22,593 (246)
Highlights of Astronomy, 1974 At the present time the planetary ephemerides in the Astronomical Ephemeris and in the American Ephemeris and Nautical Almanac (both hereinafter referred to as the AE), the Astronomical Ephemeris of the U.S.S.R. and most other national almanacs have the following basis: For Mercury, Venus, Earth, and Mars the general theories of Simon Newcomb (1898a ...
R. L. Duncombe +2 more
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What brakes the Crab pulsar? [PDF]
, 2015 Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio ...
Barbieri, C. +6 more
core +2 more sources
Transactions of the International Astronomical Union, 1982 The period of this Report includes 1984 January 1, the date which was probably the most drastic caesura in the history of astronomical almanacs. It seemed, therefore, appropriate to concentrate here to the general aspects rather than to describe the works going on at the particular almanac offices.
A M Sinzi +10 more
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A ring as a model of the main belt in planetary ephemerides [PDF]
, 2010 We assess the ability of a solid ring to model a global perturbation induced by several thousands of main-belt asteroids. The ring is first studied in an analytical framework that provides an estimate of all the ring's parameters excepting mass.
A. Fienga +12 more
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Commission No. 4: Ephemerides (Ephemerides) [PDF]
Transactions of the International Astronomical Union, 1988 It was the President’s sad duty to report the deaths of two former past Presidents of the Commission, W. Fricke who had also been a Vice-President of the IAU and a President of Commission 8, and D. H. Sadler who had been Superintendent of H.M. Nautical Almanac Office from 1936 to 1969 and was once General Secretary of the IAU.
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Maya records of planetary conjunctions in Dresden Codex [PDF]
Serbian Astronomical JournalOld Mayas designed a very complicated calendar, and they also recorded important historical events and astronomical phenomena. Dresden Codex (DC), one of the four preserved Mayan hieroglyphic literal legacies, contains many of these, covering ...
Vondrák J., Böhm V., Böhm B.
doaj +1 more source
IEEE Access, 2023 BDS-3 was formally put into service on July 31, 2020, and now along with BDS-2 provides the positioning, navigation and timing services. In this contribution, different techniques of dual-frequency absolute positioning using the fully serviceable BDS-2 ...
Shengnan Liu, Shaolin Zhu, Jian Zhang
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Transactions of the International Astronomical Union, 1970 The appended reports of the directors of the national ephemeris offices provide a record of the current activity in the publication and preparation of astronomical ephemerides, including those published for use by navigators and surveyors and those prepared for astronomers whose special needs are not met in the printed almanacs.
G. A. Wilkins +5 more
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Izračun položaja GPS-satelita iz podatkov oddanih efemerid : GPS-Orbit Computation from Broadcast Ephemeris Data [PDF]
Geodetski Vestnik, 2004 The article describes the theoretical point of view of the GPS-broadcast ephemerides application. Beside the raw GPS observations, any kind of GPS ephemerides represents indispensable data in the GPS processing engine.
Bojan Stopar +1 more
doaj
Remote Sensing, 2021 Positioning accuracy is affected by the combined effect of user range errors and the geometric distribution of satellites. Dilution of precision (DOP) is defined as the geometric strength of visible satellites.
Haomeng Cui, Shoujian Zhang
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