scholarly journals The Variation of UT from 700 BC to the Present

1995 ◽  
Vol 10 ◽  
pp. 258-258
Author(s):  
F.R. Stephenson ◽  
L.V. Morrison
Keyword(s):  
High Precision ◽  
Arab World ◽  
Precision Data ◽  
High Precision Data ◽  
Answering Questions

AbstractRecords of solar and lunar eclipses in the period 700 BC to AD 1600 originating from the ancient and medieval civilisations of Babylon, China, Europe and the Arab world are amassed and critically appraised for their usefulness in answering questions about the long-term variability of the Earth’s rate of rotation. Results from previous analyses of lunar occultations in the period AD 1600-1955.5 and from high-precision data in AD 1955.5-1990 are included in the dataset considered in this paper.

Long-term fluctuations in the Earth’s rotation: 700 BC to AD 1990

1995 ◽  
Vol 351 (1695) ◽  
pp. 165-202 ◽  
Keyword(s):  
High Precision ◽  
Arab World ◽  
Earth’S Rotation ◽  
Precision Data ◽  
Earth's Rotation ◽  
High Precision Data ◽  
Answering Questions

Records of solar and lunar eclipses in the period 700 BC to AD 1600, originating from the ancient and medieval civilizations of Babylon, China, Europe and the Arab world, are amassed and critically appraised for their usefulness in answering questions about the long-term variability of the Earth’s rate of rotation. Results from previous analyses of lunar occupations in the period AD 1600-1955.5, and from high-precision data in AD 1955.5-1990, are included in the dataset considered in this paper.

scholarly journals Transit-period search from single-event space-based data: the role of wide-field surveys

2019 ◽  
Vol 625 ◽  
pp. A145
Author(s):  
Geza Kovacs
Keyword(s):  
High Precision ◽  
Wide Field ◽  
Precision Data ◽  
Frequency Spectra ◽  
Transiting Planets ◽  
High Precision Data ◽  
Space Data ◽  
Signal Search

We investigate the optimization of dataset weighting in searching for the orbital period of transiting planets when high-precision space-based data with a single transit event are combined with (relatively) low-precision ground-based (wide-field) data. The optimization stems from the lack of multiple events in the high-precision data and the likely presence of such events in the low-precision data. With noise minimization, we combined two types of frequency spectra: (i) spectra that use two fixed transit parameters (moment of the center of the transit and duration of the event) derived from the space data alone; (ii) spectra that result from the traditional weighted box signal search with optimized transit parameters for each trial period. We used many mock signals to test the detection power of the method. Marginal or no detections in the ground-based data may lead to secure detections in the combined data with the above weighting. Depending on the coverage and quality of the ground-based data, transit depths of ~0.05% and periods up to ~100 days are accessible by the suggested optimum combination of the data.

scholarly journals A high precision data encryption algorithm in wireless network mobile communication

2019 ◽  
Vol 12 (4-5) ◽  
pp. 1327-1340 ◽  
Author(s):  
Aiwan Fan ◽  
◽  
Qiming Wang ◽  
Joyati Debnath ◽  
◽  
...  
Keyword(s):  
Wireless Network ◽  
High Precision ◽  
Mobile Communication ◽  
Data Encryption ◽  
Encryption Algorithm ◽  
Precision Data ◽  
High Precision Data

scholarly journals Updated astrometry and masses of the LUH 16 brown dwarf binary

2018 ◽  
Vol 618 ◽  
pp. A111 ◽  
Author(s):  
P. F. Lazorenko ◽  
J. Sahlmann
Keyword(s):  
High Precision ◽  
Photographic Plate ◽  
Brown Dwarf ◽  
Precision Data ◽  
Orbital Parameters ◽  
Very Large Telescope ◽  
High Precision Data ◽  
The Absolute ◽  
The Individual

The nearest known binary brown dwarf WISE J104915.57–531906.1AB (LUH 16) is a well-studied benchmark for our understanding of substellar objects. Previously published astrometry of LUH 16 obtained with FORS2 on the Very Large Telescope was affected by errors that limited its use in combination with other datasets, thereby hampering the determination of its accurate orbital parameters and masses. We improve upon the calibration and analysis of the FORS2 astrometry with the help of Gaia DR2 to generate a high-precision dataset that can be combined with present and future LUH 16 astrometry. We demonstrate its use by combining it with available measurements from the Hubble Space Telescope (HST) and Gemini/GeMS and deriving updated orbital and mass parameters. Using Gaia DR2 as astrometric reference field, we derived the absolute proper motion and updated the absolute parallax of the binary to 501.557 ± 0.082 mas. We refined the individual dynamical masses of LUH 16 to 33.5 ± 0.3 M Jup (component A) and 28.6 ± 0.3 M Jup (component B), which corresponds to a relative precision of ∼1% and is three to four times more precise than previous estimates. We found that these masses show a weak dependence on one datapoint extracted from a photographic plate from 1984. The exact determination of a residual mass bias, if any, will be possible when more high-precision data can be incorporated in the analysis.

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