Impact of seasonal station motions on VLBI UT1 intensives results |
| |
| Authors: | Zinovy Malkin |
| |
| Institution: | 1. Pulkovo Observatory, Pulkovskoe Sh. 65, St. Petersburg, 196140, Russia
2. St. Petersburg State University, Universitetskii Pr. 28, St. Petersburg, 198504, Russia
|
| |
| Abstract: | UT1 estimates obtained from the very long baseline interferometry (VLBI) Intensives data depend on the station displacement model used during processing. In particular, because of seasonal variations, the instantaneous station position during the specific intensive session differs from the position predicted by the linear model generally used. This can cause systematic errors in UT1 Intensives results. In this paper, we first investigated the seasonal signal in the station displacements for the 5 VLBI antennas participating in UT1 Intensives observing programs, along with the 8 collocated GPS stations. It was found that a significant annual term is present in the time series for most stations, and its amplitude can reach 8 mm in the height component, and 2 mm in horizontal components. However, the annual signals found in the displacements of the collocated VLBI and GPS stations at some sites differ substantially in amplitude and phase. The semiannual harmonics are relatively small and unstable, and for most stations no prevailing signal was found in the corresponding frequency band. Then two UT1 Intensives series were computed with and without including the seasonal term found in the previous step in the station movement model. Comparison of these series has shown that neglecting the seasonal station position variations can cause a systematic error in UT1 estimates, which can exceed 1 $\upmu $ s, depending on the observing program. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
