TIDAL STATION DISPLACEMENTS

Theoretical modeling of the station displacements produced by tidal de formations of the Earth due to lunisolar gravitational forces is a nec essary part of the analysis of space geodetic data. To attain the accu racies demanded by the precision of the data, a generalized version of the Love number formalism has to be used wherein the classical Love a nd Shida numbers are replaced by sets of Love number parameters with v alues that depend on the frequency of the tidal excitation. This paper presents theoretical expressions for the contributions from the vario us Love number parameters to the station displacement vector and a sch eme for efficient computation of these contributions, taking into acco unt the frequency dependence of these parameters as well as the imagin ary parts that are present when the effects of mantle anelasticity are taken into account. A brief discussion of the permanent tide which ar ises from the zero frequency component of the tide-generating potentia l is included.