[G02-1] Theory and methods

[G02-1-02] Gravitational contribution of a spherical tesseroid by means of mapping it into sectors of spherical band

^○Anna Maria Marotta¹, Riccardo Barzaghi² (1.Universita' degli Studi di Milano, Department of Earth Sciences Ardito Desio, Milano, Italy, 2.Politecnico di Milano, DICA, Milano, Italy)

We present a new methodology for computing the gravitational effect of a spherical tesseroid, based on the rotation from the global Earth-Centred Rotational reference frame to the local Earth-Centred P-Rotational reference. After rotation, the gravitational effect of the tesseroid is computed via the effect of a sector of spherical zonal band. In this respect, two possible procedures to handle the rotated tesseroids have been proposed and tested, one based on the re-orientation of the rotated tesseroids, and the other based on a second-order tesseroidal decomposition. Sensitivity tests show that the RT procedure is adequate in estimating the gravitational effects at distances greater than 0.1 degree from the computation point; the more accurate ST procedure is required at closer distances. The implemented procedure has been tested against other methods known in literature. In particular, benchmark tests have been carried out with respect to the methods proposed by Heck and Seitz (2207), Hirth and Kuhn (2014) and Uieda et al. (2015). The comparative analysis showed that the new devised methodology is in good agreement with all the above-mentioned methods and can be thus used within future more general benchmark studies.