An analysis of source motions derived from position time series

TL;DR

This paper investigates the systematic components of radio source motions derived from position time series, revealing significant differences across datasets that hinder reliable modeling of source velocities using spherical harmonics.

Contribution

It provides an analysis of source motion data from multiple centers, highlighting variability and challenges in modeling systematic motions.

Findings

Source velocities and systematic parameters vary significantly between datasets.

Current data does not support reliable spherical harmonic coefficient estimation.

Preliminary results indicate the need for improved data consistency.

Abstract

In this paper an attempt is made to extract a systematic part from the source motions obtained from the position time series provided by several IVS Analysis Centers in the framework of the ICRF-2 project. Our preliminary results show that the radio source velocities and the parameters of the systematic part of the velocity field differ substantially between the source position time series, which does not allow us to get a reliable solution for the coefficients of spherical harmonics.