Abstract: An unmanned aircraft includes three parallel beams extending in at least one longitudinal direction X from a rear side to a front side of the aircraft, the central beam forming a main fuselage containing a powertrain, with a propeller of diameter D configured to be driven by the powertrain being attached to a front end of the central beam, each side beam being at a distance L/2 from the central beam and each side beam supporting a radar at a front end of the beam.

Abstract: Method for controlling an unmanned aircraft piloted by a fully autonomous control system including a first decision module and a simplex piloting control module including a high-performance controller, a high-safety controller and a second decision module, the high-performance and high-safety controllers determining piloting commands for the robot-aircraft, according to which: —as long as a set of conditions is verified, implementation by the first decision module of a nominal piloting mode with delivery to the output of the automatic control system of the piloting commands delivered to the output of the simplex piloting control module; —otherwise, switching to an emergency piloting mode, an emergency piloting command is delivered to the output of the automatic control system for execution by the robot-aircraft, the first decision module preventing the delivery to the output of the automatic control system of the piloting commands delivered to the output of the simplex module.

Abstract: The detector elements are sensitive to the target presence in their respective vicinities and are distributed in the surveillance zone. First differences (S1-S2, S3-S2, S4-S2) are formed from outputs of the detector elements taken pairwise, and at least one other first difference (S3-S2, S4-S2) previously filtered in a filter (213, 213') is subtracted from each first difference (S1-S2) to form a second difference, where said filter is controlled to minimize the value of the second difference in the absence of a target, and the second differences so obtained are used (216) to detect the target. In particular the invention applies to detecting submarines using magnetometer buoys.