For the process for determining a distance, there is provided a succession of coded signals at high frequency transmitted between a base station and a wearable object. A preparation of a response signal is conducted in the wearable object on reception of the first synchronisation signal after activation of the wearable object. A transmission of successive coded signals at high frequency from the wearable object is conducted for the station, of which the last response signal is scrambled by a modulation of data on the last signal received at a high transfer rate from the station. An analysis is conducted in a processing unit of the base station after reception of the signals from the wearable object to accurately determine the distance separating the base station from the recognised wearable object.