A method of guiding along a reference trajectory on a ground platform an aircraft carrying at least one detector adapted to detect the position of a plurality of indicators marking taxiing areas, said method comprising the following steps implemented by a data processing module capable of being connected to said at least one detector: (a) determining geometrically complex uncertainty zones of the platform from a mapping of the platform, b) in the vicinity of one of said determined uncertainty zones, selecting of several indicators from the plurality of ground indicators detected by said at least one detector, c) estimating a relative location of the aircraft with respect to said reference trajectory from data relating to the selected indicators transmitted by said at least one detector, d) calculating a confidence index representing the probability that these ground indicators are appropriate for guiding the aircraft on the reference trajectory, e) comparing the calculated confidence index to a predetermined threshold, f) when the calculated confidence index is greater than the predetermined threshold, automatic guidance of the aircraft by the processing module along the reference trajectory according to the estimated relative location, and when the calculated confidence index is less than the predetermined threshold, perform steps b) through e) again, then the method comprises: - after a predetermined time has elapsed without the calculated confidence index being greater than the predetermined threshold, or - after a predetermined number of executions of steps b) through e) during which the confidence index is below the predetermined threshold, or - when there is no longer an indicator among the plurality of ground indicators for which no confidence index has been calculated, - transmission by the processing module of an alarm message to a pilot requesting that the aircraft be driven in manual mode or warning of a switch to manual mode during a manual guidance step. said method comprising the following steps implemented by a data processing module capable of being connected to said at least one detector: (a) determining geometrically complex uncertainty zones of the platform from a mapping of the platform, b) in the vicinity of one of said determined uncertainty zones, selecting of several indicators from the plurality of ground indicators detected by said at least one detector, c) estimating a relative location of the aircraft with respect to said reference trajectory from data relating to the selected indicators transmitted by said at least one detector, d) calculating a confidence index representing the probability that these ground indicators are appropriate for guiding the aircraft on the reference trajectory, e) comparing the calculated confidence index to a predetermined threshold, f) when the calculated confidence index is greater than the predetermined threshold, automatic guidance of the aircraft by the processing module along the reference trajectory according to the estimated relative location, and (a) determining geometrically complex uncertainty zones of the platform from a mapping of the platform, b) in the vicinity of one of said determined uncertainty zones, selecting of several indicators from the plurality of ground indicators detected by said at least one detector, c) estimating a relative location of the aircraft with respect to said reference trajectory from data relating to the selected indicators transmitted by said at least one detector, d) calculating a confidence index representing the probability that these ground indicators are appropriate for guiding the aircraft on the reference trajectory, e) comparing the calculated confidence index to a predetermined threshold, f) when the calculated confidence index is greater than the predetermined threshold, automatic guidance of the aircraft by the processing module along the reference trajectory according to the estimated relative location, and when the calculated confidence index is less than the predetermined threshold, perform steps b) through e) again, then the method comprises: - after a predetermined time has elapsed without the calculated confidence index being greater than the predetermined threshold, or - after a predetermined number of executions of steps b) through e) during which the confidence index is below the predetermined threshold, or - when there is no longer an indicator among the plurality of ground indicators for which no confidence index has been calculated, - transmission by the processing module of an alarm message to a pilot requesting that the aircraft be driven in manual mode or warning of a switch to manual mode during a manual guidance step. - after a predetermined time has elapsed without the calculated confidence index being greater than the predetermined threshold, or - after a predetermined number of executions of steps b) through e) during which the confidence index is below the predetermined threshold, or - when there is no longer an indicator among the plurality of ground indicators for which no confidence index has been calculated, - transmission by the processing module of an alarm message to a pilot requesting that the aircraft be driven in manual mode or warning of a switch to manual mode during a manual guidance step.