Abstract: A marker that can be used to increase the precision and efficiency of the guidance of homing heads towards a target. In order to mark targets on land, this marker has: an ovoid casing provided with a firing fuse, and a magnet and a coil for detecting flux variations during an impact on a magnetic surface. Inside the casing there are: a battery, an electronic control and transmission circuit, and a cylinder of thrustors connected to one another by pyrotechnical delaying mechanisms. The cylinder opens out on to a single nozzle which is inclined with respect to the axis of the casing. After impact on the ground, the electronic circuit controls the firing of the first thrustor. The other thrustors cause leaps until the marker gets fixed to a magnetic surface, through the magnet.

Abstract: This process for detecting the coming interposition of a mask between an aircraft (A) and a target (C), particularly in a laser-guided weapon firing system, wherein the aircraft has an automatic target tracking system providing an image of the terrain on which the target occupies a permanent fixed position, consists in detecting, during a turn carried out by the aircraft, the points M of this image, marked by their elevation i.sub.m -i.sub.c with respect to the target C, situated in a zone such that i.sub.M -i.sub.C <0 and having an angular progression velocity, with respect to the target, opposite to that of the other points in that zone at the same altitude as the target.Application in particular to laser-guided weapon firing systems.