On Estimating the Accuracy of the High-Frequency Universal Time Series

S. L. Kurdubov, E. A. Skurikhina

Transactions of IAA RAS, issue 57, 23–27 (2021)

DOI: 10.32876/ApplAstron.57.23-27

Keywords: parameters of the Earth's rotation, universal time, EOP service, VLBI, spectral analysis

Abstract

This article investigates a method for estimating the accuracy of a universal time series with a high temporal resolution based on estimates of the internal smoothness of the series itself. The smoothed UT1-UTC time series were constructed by rolling polynomial interpolations of various degrees. The series obtained in this way is compared with the initial one; the standard deviation of the differences is proposed as an estimate of the internal accuracy of the series. The series smoothed in this way is compared with the series of the International Earth Rotation Service and Coordinate Systems (IERS). The article uses a series of Universal Time obtained at the IAA RAS as a result of 1-hour observations of geodetic radio sources (quasars) with 13-meter high-speed radiointerferometric antennas of a new generation (VGOS), located at Badary and Zelenchukskaya. Observations were carried out in the S/X ranges according to the R observation program 3–4 times a day. Correlation processing was carried out on the RAS FX IAA RAS correlator. Secondary data processing was performed using the QUASAR software package developed at the IAA RAS. To analyze the accuracy of the series, the period from February 2019 to February 2020 was used in the article. As a reference series, we used a series of the International Earth Rotation Service and Reference Systems (IERS), namely a series of ERP (Earth rotation parameters) of the urgent service of the IERS-finals. It was shown that the IAA RAS high frequency UT1-UTC series has no long term differences with the IERS finals. The smoothed IAA RAS series has differences at the level of 18 µs RMS with the IERS finals. The high-frequency fluctuations of the series are partly of a harmonic nature and may be due to the inaccuracy of the model of the EOP intraday variations.

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