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H. Krasna:
"Bestimmung von Love-Zahlen und FCN-Periode aus VLBI-Daten";
Österreichische Zeitschrift für Vermessung und Geoinformation (VGI), 4 (2014), 187 - 192.

The gravitational attraction of the Moon and the Sun causes deformation of the Earth´s surface which can reach
several decimetres in vertical direction during a day. The displacement is a function of the so-called Love numbers (vertical direction) and Shida numbers (horizontal plane). Due to the present accuracy of the VLBI measurements the parameters have to be specified as complex numbers, where the imaginary parts describe the anelasticity of the Earth´s mantle. Moreover, it is necessary to distinguish between the single tides within the various frequency bands. On the other hand, the increasing accuracy of the space geodetic techniques, such as Very Long Baseline Interferometry (VLBI), allows access to these parameters in the theoretical models and provides possibilities to validate them directly from the measured data. In this work Love numbers of twelve diurnal tides included in the solid Earth tidal displacement modelling are estimated directly from 27 years of VLBI measurements (1984.0 - 2011.0). Furthermore, the period of the Free Core Nutation (FCN) is computed which shows up in the frequency-dependent solid Earth tidal displacement as well as in a nutation model describing the motion of the Earth´s axis in space. The FCN period in both models is treated as a single parameter and its estimated value is −431.18 - 0.10 sidereal days.

Love and Shida numbers, solid Earth tides, Free Core Nutation, Very Long Baseline Interferometry

https://publik.tuwien.ac.at/files/publik_240167.pdf