The impact of errors in polar motion and nutation on UT1 determinations from VLBI Intensive observations |
| |
Authors: | Axel Nothnagel Dorothee Schnell |
| |
Institution: | (1) Institute of Geodesy and Geoinformation, Nussallee 17, 53115 Bonn, Germany |
| |
Abstract: | The earth’s phase of rotation, expressed as Universal Time UT1, is the most variable component of the earth’s rotation. Continuous
monitoring of this quantity is realised through daily single-baseline VLBI observations which are interleaved with VLBI network
observations. The accuracy of these single-baseline observations is established mainly through statistically determined standard
deviations of the adjustment process although the results of these measurements are prone to systematic errors. The two major
effects are caused by inaccuracies in the polar motion and nutation angles introduced as a priori values which propagate into
the UT1 results. In this paper, we analyse the transfer of these components into UT1 depending on the two VLBI baselines being
used for short duration UT1 monitoring. We develop transfer functions of the errors in polar motion and nutation into the
UT1 estimates. Maximum values reach 30 μs per milliarcsecond] which is quite large considering that observations of nutation
offsets w.r.t. the state-of-the-art nutation model show deviations of as much as one milliarcsecond. |
| |
Keywords: | Universal Time UT1 Geodetic VLBI Intensive observations Polar motion and nutation |
本文献已被 SpringerLink 等数据库收录! |