Polar Motion Influences in the Gravity Data Recorded by Superconducting Gravimeters

Martina Harnisch , Günter Harnisch

Gravity data stored in the GGP database (GGP-ISDC) are used to study the small gravity variations caused by polar motion. In a first step the dominant tidal signal and the instrumental drift have to be eliminated from the gravity data. In most cases it is sufficient to model the instrumental drift by polynomials of low degree. The resulting non-tidal gravity variations are split up into their main constituents by fitting two sinusoidal waves with periods of 365.25 days (Annual Wobble) and 432 days (Chandler Wobble). In a similar way the gravity effect of the observed polar motion (IERS-Data) is processed. The ratio between the correspondent amplitudes gives the amplitude factors δ of both wobbles.

Mots clés: Superconducting gravimeter; Global Geodynamics Project (GGP); Polar motion; Estimation of parameters; Worldwide stacking

Martina Harnisch, Günter Harnisch. Polar Motion Influences in the Gravity Data Recorded by Superconducting Gravimeters. Journal of Geodynamics, 2009, 48 (3-5), pp.340. ⟨10.1016/j.jog.2009.09.015⟩. ⟨hal-00594433⟩