A method for estimating a distance by ultrasonic telemetry, comprising the following steps: a) emitting, from a time instant of origin, a burst of ultrasound, this emission being repeated at a predetermined recurrence frequency; b) after the end of each emission and for the duration of a time frame ( n -1, n, n +1,...) separating two consecutive emissions, receiving a plurality of successive signal peaks occurring at respective instants of arrival during a same frame, these successive signal peaks including spurious peaks (E' n -1, E' n, E' n +1,...) and one useful peak (E n -1, E n, E n +1,...) corresponding to the distance to be estimated; c) for two consecutive frames, comparing the instants of arrival of the p signal peaks of the current frame with the instants of arrival of the q signal peaks of the preceding frame, and determining, for each of the p.q peak couples, a corresponding relative time difference; d) selecting a single peak of the current frame as a function of the p.q relative time differences determined at step c); and e) estimating the distance as a function of the instant of arrival of the peak kept à step d) with respect to the time of emission of the last burst, characterized in that: - this method is implemented by a drone for a measurement of altitude (h) of the drone; - it is provided a previous step of adjusting said recurrence frequency to a predetermined value different from the corresponding recurrence frequency of another drone intended to be used at the same time of the considered drone, the respective recurrence frequencies of the considered drone and of the other drone being adjusted so that the difference between these frequencies meets the relation: abs F 1 − F 2 / max F 1 F 2 > 2 * V max / c + W * min F 1 F 2 / F s F 1 being the recurrence frequency of said considered drone, F 2 being the recurrence frequency of said other drone, V max being the maximum speed, in the direction of estimation of the distance, of said considered drone, c being the sound propagation speed, W being the time width of the burst, and F s being the frequency of sampling of the received signal; - the step b) includes the possible receipt of spurious peaks coming from emissions of bursts of ultrasound from the other drone; and - the step d) comprises a filtering through which are kept only the peaks of the current frame for which the relative time difference with the peaks of the preceding frame is lower than a predetermined threshold. a) emitting, from a time instant of origin, a burst of ultrasound, this emission being repeated at a predetermined recurrence frequency; b) after the end of each emission and for the duration of a time frame ( n -1, n, n +1,...) separating two consecutive emissions, receiving a plurality of successive signal peaks occurring at respective instants of arrival during a same frame, these successive signal peaks including spurious peaks (E' n -1, E' n, E' n +1,...) and one useful peak (E n -1, E n, E n +1,...) corresponding to the distance to be estimated; c) for two consecutive frames, comparing the instants of arrival of the p signal peaks of the current frame with the instants of arrival of the q signal peaks of the preceding frame, and determining, for each of the p.q peak couples, a corresponding relative time difference; d) selecting a single peak of the current frame as a function of the p.q relative time differences determined at step c); and e) estimating the distance as a function of the instant of arrival of the peak kept à step d) with respect to the time of emission of the last burst, - this method is implemented by a drone for a measurement of altitude (h) of the drone; - it is provided a previous step of adjusting said recurrence frequency to a predetermined value different from the corresponding recurrence frequency of another drone intended to be used at the same time of the considered drone, the respective recurrence frequencies of the considered drone and of the other drone being adjusted so that the difference between these frequencies meets the relation: abs F 1 − F 2 / max F 1 F 2 > 2 * V max / c + W * min F 1 F 2 / F s F 1 being the recurrence frequency of said considered drone, F 2 being the recurrence frequency of said other drone, V max being the maximum speed, in the direction of estimation of the distance, of said considered drone, c being the sound propagation speed, W being the time width of the burst, and F s being the frequency of sampling of the received signal; F 1 being the recurrence frequency of said considered drone, F 2 being the recurrence frequency of said other drone, V max being the maximum speed, in the direction of estimation of the distance, of said considered drone, c being the sound propagation speed, W being the time width of the burst, and F s being the frequency of sampling of the received signal; - the step b) includes the possible receipt of spurious peaks coming from emissions of bursts of ultrasound from the other drone; and - the step d) comprises a filtering through which are kept only the peaks of the current frame for which the relative time difference with the peaks of the preceding frame is lower than a predetermined threshold.