Abstract: A method of detecting a heat source in an area to be watched consists of disposing a detector on a support elevated with respect to the area to effect a sweeping motion at least in a horizontal plane. Points in the area to be watched are defined by the angular position of the detector in the horizontal and vertical planes when the detector is directed toward a point and by at least one associated additional data element that impounds the geographic position of the point in a predetermined reference system.

Abstract: A station for locating through laser rays an object likely to diffuse back a part of the incident laser ray, wherein the optical emitter and receiver devices consist of one single device comprising, in the direction of emission, a device for separating the emitted and retrodiffused rays, an optical device converting the emitted parallel beam of small diameter into a divergent beam and a telescope adapted to collimate the divergent beam received from the optical device into a parallel beam of larger diameter, the retrodiffused beam travelling that path in the direction reverse from the emitted beam, the invention being usable for detecting in particular forest fire smokes.