Abstract: A method and system for the avoidance of collisions among aircraft in which monochromatic radiation is transmitted from an aircraft fitted out with a wide-field optical transceiver. The monochromatic radiation scans the space around the aircraft which defines a zone of proximity. Optical radiation is returned after back reflection off objects which may be sources of danger constituted by other aircraft that have entered the zone of proximity. The radiation received is detected and then processed to deduce therefrom the direction and, as the case may be, the distance of the source of danger. Such a method can be applied especially to the avoidance of collision between non-cooperating aircraft.

Abstract: In a system of optical communications that can be used by air or space vehicles, each station comprises at least one optical system covering a half space, this system comprising two twinned optical devices to respectively form two distinct reception channels: a first reception optical channel for the initialization, in space, of the direction of communication; a second optical channel for the reception of the contents of the communication. One of the two optical devices is also used to form a transmission channel for the initialization and then for the communication in the direction of communication. The setting up of communication is done in three steps, respectively target designation, iterative bilateral acquisition and interstation communication.