A method for detecting parasitic movements during static alignment of an inertial unit, the method being characterized by steps of: • receiving radio navigation measurements acquired by a receiver from signals previously transmitted by a set of radio navigation satellites, • estimating a displacement of the inertial unit from the measurements acquired, • comparing the estimated displacement with a predetermined threshold, • signaling a parasitic movement of the inertial unit when the displacement crosses the predetermined threshold, characterized in that estimating the displacement of the inertial unit from the acquired measurements comprises the following steps, conducted for each satellite: • calculation of a position variation from: ∘ a phase of a first radio navigation signal transmitted by the satellite and received by the receiver at an initial reception time, and ∘ a phase of a second radio navigation signal transmitted by the satellite and received by the receiver at a subsequent reception time, • estimation of a displacement of the receiver relative to the satellite between the initial reception time and the subsequent reception time, from the following data: ∘ a position of the satellite at the initial reception time, ∘ a position of the satellite at the subsequent reception time, ∘ a position at the initial reception time provided by the inertial unit, and ∘ a position at the subsequent reception time provided by the inertial unit, • calculation of a deviation between the calculated variation in position and the estimated displacement of the receiver relative to the satellite, the estimated displacement of the inertial unit depending on this deviation. • receiving radio navigation measurements acquired by a receiver from signals previously transmitted by a set of radio navigation satellites, • estimating a displacement of the inertial unit from the measurements acquired, • comparing the estimated displacement with a predetermined threshold, • signaling a parasitic movement of the inertial unit when the displacement crosses the predetermined threshold, • calculation of a position variation from: ∘ a phase of a first radio navigation signal transmitted by the satellite and received by the receiver at an initial reception time, and ∘ a phase of a second radio navigation signal transmitted by the satellite and received by the receiver at a subsequent reception time, ∘ a phase of a first radio navigation signal transmitted by the satellite and received by the receiver at an initial reception time, and ∘ a phase of a second radio navigation signal transmitted by the satellite and received by the receiver at a subsequent reception time, • estimation of a displacement of the receiver relative to the satellite between the initial reception time and the subsequent reception time, from the following data: ∘ a position of the satellite at the initial reception time, ∘ a position of the satellite at the subsequent reception time, ∘ a position at the initial reception time provided by the inertial unit, and ∘ a position at the subsequent reception time provided by the inertial unit, ∘ a position of the satellite at the initial reception time, ∘ a position of the satellite at the subsequent reception time, ∘ a position at the initial reception time provided by the inertial unit, and ∘ a position at the subsequent reception time provided by the inertial unit, • calculation of a deviation between the calculated variation in position and the estimated displacement of the receiver relative to the satellite, the estimated displacement of the inertial unit depending on this deviation.