On a Recent Preliminary Study for the Measurement of the LenseThirring Effect with the Galileo Satellites
Abstract
It has recently been proposed to combine the node drifts of the future constellation of 27 Galileo spacecraft together with those of the existing Laser Geodynamics Satellites (LAGEOS)type satellites to improve the accuracy of the past and ongoing tests of the LenseThirring (LT) effect by removing the bias of a larger number of even zonal harmonics J_{ℓ} than either done or planned so far. Actually, it seems a difficult goal to be achieved realistically for a number of reasons. First, the LT range signature of a Galileotype satellite is as small as 0.5 mm over threedays arcs, corresponding to a node rate of just ˙ Ω _{} LT = 2 milliarcseconds per year (mas yr^{1}). Some tesseral and sectorial ocean tides such as K_{1} and K_{2} induce longperiod harmonic node perturbations with frequencies which are integer multiples of the extremely slow Galileo's node rate ˙ Ω completing a full cycle in about 40 yr. Thus, over time spans, T, of some years, they would act as superimposed semisecular aliasing trends. Since the coefficients of the J_{ℓ}free multisatellite linear combinations are determined only by the semimajor axis a, the eccentricity e and the inclination I, which are nominally equal for all the Galileo satellites, it is not possible to include all of them. Even using only one Galileo spacecraft together with the LAGEOS family would be unfeasible because of the fact that the resulting Galileo coefficient would be ≳ 1, thus enhancing the aliasing impact of the uncancelled nonconservative and tidal perturbations.
 Publication:

International Journal of Modern Physics D
 Pub Date:
 January 2014
 DOI:
 10.1142/S021827181450028X
 arXiv:
 arXiv:1311.6109
 Bibcode:
 2014IJMPD..2350028I
 Keywords:

 Experimental studies of gravity;
 experimental tests of gravitational theories;
 satellite orbits;
 earth tides;
 harmonics of the gravity potential field;
 04.80.y;
 04.80.Cc;
 91.10.Sp;
 91.10.Tq;
 91.10.Qm;
 Experimental studies of gravity;
 Experimental tests of gravitational theories;
 Satellite orbits;
 Earth tides;
 Harmonics of the gravity potential field;
 geopotential theory and determination;
 General Relativity and Quantum Cosmology;
 Astrophysics  Earth and Planetary Astrophysics;
 Physics  Geophysics;
 Physics  Space Physics
 EPrint:
 LaTex2e, 23 pages, 10 tables, 4 figures, 39 references. Accepted for publication in International Journal of Modern Physics D (IJMPD)