Ocean loading station displacements observed by VLBI

Ocean tidal loading causes small displacements of VLBI observing stations that should be taken into account in VLBI data analysis. The a posteriori delay and delay rate errors of least squares fits of those VLBI experiments with stations near ocean coasts and on islands are shown to decrease significantly after correcting the VLBI observables for the ocean loading effect. In extreme cases station coordinates and baseline lengths may change by a few centimeters after applying the ocean loading corrections. Conversely, these results demonstrate that ocean tidal loading can be monitored using high precision VLBI. However, the present global ocean tidal loading model is still inadequate for some stations and should be expanded for future applications.