Method of ultrasound telemetry for drones, with discrimination of spurious echos emanating from another drone

The method comprises: a) the emission of an ultrasound burst repeated at a predetermined recurrence frequency; and b) after each emission and for the duration of a time frame (n-1, n, n+1, . . . ) separating two consecutive emissions, the reception of a plurality of successive signal spikes appearing in the course of the same frame. These spikes include spurious spikes (E'n-1, E'n, E'n+1, . . . ) originating from the emitter of another drone, and a useful spike (En-1, En, En+1, . . . ) corresponding to the distance to be estimated. To discriminate these spikes, the following steps are executed: c) for two consecutive frames, comparison of the instants of arrival of the p spikes of the current frame with the instants of arrival of the q spikes of the previous frame and determination, for each of the p.q pairs of spikes, of a corresponding relative time gap; d) application to the p.q gaps determined in step c) of a selection criterion making it possible to retain just a single spike of the current frame; and e)