Chapter 4 Earth rotation variations from Very Long Baseline Interferometry

摘要

While the preceding chapters give the theoretical framework of Earth rotation and treat the causes and consequences of tidal phenomena, the present and following chapters deal with the observation of Earth rotation variability by means of space geodetic techniques. The first measurement system, to be treated in this chapter, is the geodetic VLBI. It is one of the most important techniques for Earth rotation monitoring as it grants access to the full set of Earth orientation parameters, nutation offsets, dUTl and polar motion. Since a complete description of the functionality would go beyond the scope of this thesis, only an outline of the VLBI system with special focus on the aspects relevant for Earth rotation observation shall be given.