Champ de gravité terrestre: une alternative aux harmoniques sphériques par les ondelettes

Abstract

The research work describes the gravity field of a lying body (here, the Earth) in an alternative form, with the help of a family of wavelets, known as the Poisson wavelets, built on the sphere. This kind of representation is particularly adapted to the high (and even very high) degrees of the gravitational field, for which the traditional representations fail. These highest degrees are now available thanks to the new space missions like CHAMP, GRACE and GOCE. Our work is based on the articles of [Panet et al. 2005] and of [Deleflie 2002]. After the description of the spherical harmonics, the families of wavelets in the plane and some one dimensional tests to validate the model, the research work will study the perturbations generated by a particular wavelet on a satellite flight path. To achieve this we use the method of inversion of the orbital perturbations to know the coefficients of the field with a greater accuracy and at the higher orders.

Date of Award	2005
Original language	French
Supervisor	Florent Deleflie (Co-Supervisor), Dominique Lambert (Jury) & Anne Lemaitre (Supervisor)