A method for estimating the bearing of an optronic system in a geographical reference frame, the optronic system being situated at a first position and denoted first optronic system is provided. It comprises the following steps: defining a collaborative configuration, by way of the first optronic system and of at least one other optronic system, the optronic systems being respectively situated at separate positions and equipped with means for communication with one another, and with acquisition devices, acquiring, in a scene, one or more objects common to the optronic systems, the direction of orientation between each optronic system and each object being unknown, determining two positions from among those of the optronic systems, for at least one common object: measuring the relative angle by way of a relative angle measurement device fitted to the first optronic system, measuring the elevation of the object by way of an elevation measurement device fitted to the first optronic system, performing additional measurements by way of each other optronic system, with the two positions and the measurements constituting observations, communication, by the other optronic system(s) to the first optronic system, of the observations that it does not have, on the basis of the observations, estimation, by the first optronic system, of the bearing of the first optronic system.