Abstract: A method for detecting masking of one or more satellites by an obstacle for a GNSS receiver on board a movable carrier, including receiving, for each one of M satellites, a code pseudo-distance measurement and a variation of carrier pseudo-distances, computing of a definite position of the receiver and a computed position of each satellite, detecting a masking of at least one satellite on the basis of the following operations: computing, at a computation instant and for each satellite, of a computed pseudo-distance and a pseudo-distance reconstructed at a previous time, and detecting masking of at least one satellite by analyzing a magnitude, called residue, computed by applying a least squares algorithm.