Method of measuring the velocity of an aircraft at a given instant, by
laser Doppler anemometry, by performing the steps of acquiring a backscattered
signal on at least three oriented line-of-
sight axes, and calculating the spectrum of the backscattered
signal on each of the line-of-
sight axes. Further, acquiring an additional backscattered
signal on at least one additional line-of-
sight axis (X4) not coincident with one of the three first line-of-sight axes (X1, X2, X3), and calculating the spectrum of the backscattered
signal on the additional line-of-sight axis (X4). Several candidate velocity vectors ({right arrow over (V)}c) and of the projections of the candidate vectors on at least one line-of-sight axis (X1, X2, X3, X4) are calculated. The consistency of the candidate vectors ({right arrow over (V)}c) is calculated as a function of their projections and as a function of each spectrum of the corresponding backscattered
signal on the respective calculation axis (X1, X2, X3, X4). The measured
velocity vector ({right arrow over (V)}c) is chosen from among the candidate velocity vectors ({right arrow over (V)}c).