Method for estimating the movement of an object moving in an environment (Σ) and an ambient magnetic field, the method comprising the steps of: (a) Acquisition: ∘ by inertial measurement means fixed with reference to said object , of at least one component of an acceleration and/or an angular velocity of the object , designated inertial datum; ∘ by magnetic measurement means fixed with reference to said object , of at least one component of the magnetic field and/or an i-th derivative of the magnetic field, at the magnetic measurement means , designated magnetic datum; ∘ by optical acquisition means fixed with reference to said object , of consecutive images of the environment (Σ), designated vision datum; evaluation of the validity of the magnetic datum and/or the vision datum, and selection of the magnetic datum and/or the vision datum as a function of the result of said validity evaluation; one of the magnetic datum and vision datum being a default datum and the other a resetting datum, the evaluation of the validity being implemented for the default datum, and the selected datum being: o the default datum if the default datum is evaluated valid, o the resetting datum if the default datum is not evaluated valid; (b) Estimation by the data processing means of at least one component of the movement of said object using the inertial datum, as well as the datum or data selected from among the magnetic datum and the vision datum. (a) Acquisition: ∘ by inertial measurement means fixed with reference to said object , of at least one component of an acceleration and/or an angular velocity of the object , designated inertial datum; ∘ by magnetic measurement means fixed with reference to said object , of at least one component of the magnetic field and/or an i-th derivative of the magnetic field, at the magnetic measurement means , designated magnetic datum; ∘ by optical acquisition means fixed with reference to said object , of consecutive images of the environment (Σ), designated vision datum; evaluation of the validity of the magnetic datum and/or the vision datum, and selection of the magnetic datum and/or the vision datum as a function of the result of said validity evaluation; one of the magnetic datum and vision datum being a default datum and the other a resetting datum, the evaluation of the validity being implemented for the default datum, and the selected datum being: o the default datum if the default datum is evaluated valid, o the resetting datum if the default datum is not evaluated valid; ∘ by inertial measurement means fixed with reference to said object , of at least one component of an acceleration and/or an angular velocity of the object , designated inertial datum; ∘ by magnetic measurement means fixed with reference to said object , of at least one component of the magnetic field and/or an i-th derivative of the magnetic field, at the magnetic measurement means , designated magnetic datum; ∘ by optical acquisition means fixed with reference to said object , of consecutive images of the environment (Σ), designated vision datum; evaluation of the validity of the magnetic datum and/or the vision datum, and selection of the magnetic datum and/or the vision datum as a function of the result of said validity evaluation; one of the magnetic datum and vision datum being a default datum and the other a resetting datum, the evaluation of the validity being implemented for the default datum, and the selected datum being: o the default datum if the default datum is evaluated valid, o the resetting datum if the default datum is not evaluated valid; o the default datum if the default datum is evaluated valid, o the resetting datum if the default datum is not evaluated valid; (b) Estimation by the data processing means of at least one component of the movement of said object using the inertial datum, as well as the datum or data selected from among the magnetic datum and the vision datum. <EOS>