SYSTEM FOR GENERATING A RECORDING ELECTROMAGNETIC FIELD HAVING A GIVEN CONFIGURATION

The present invention pertains to the field of alarm-signal generating systems and essentially relates to a system for generating a recording electromagnetic field. This system includes an emitting unit (1) with an emitter (3) and an emitting antenna grid (4) as well as a receiving unit (2) with a receiver (7) and a receiving antenna grid (8), wherein said units are located at a distance from each other. The emitting and receiving units include diagram-generation means (6, 9) and phase-generation means (5, 10), respectively. When the electromagnetic field has a complex configuration or when it is necessary to monitor simultaneously a plurality of closed premises, the method involves using electromagnetic-radiation transformers (14) that modify the direction and the shape of said electromagnetic radiation according to the shape and the dimensions of the areas to be monitored. The present invention pertains to means for the optical processing of information used in image recognition systems. This invention essentially relates to a correlator that comprises a laser, a collimator, a light-splitting member, random-phase image masks, a mirror, objectives for generating a Fourier spectrum and correlation functions, a phase-sensitive medium, a photoreceptor and devices for displacing the images. In order to simplify its structure while maintaining a high reliability level, this correlator uses in a first embodiment a plurality of lenses which are arranged at predetermined focal distances in the optical system of said correlator or, in a second embodiment, a plurality of random-phase masks. Cette invention se rapporte aux dispositifs de traitement optique d'informations que l'on utilise dans des systèmes de reconnaissance d'images. Cette invention concerne plus précisément un corrélateur qui comprend un laser, un collimateur, un élément séparateur de lumière, des masques d'images à phase aléatoire, un miroir, des objectifs de génération d'un spectre de Fourier et de fonctions de corrélation, un milieu sensible à la phase, un photorécepteur et, enfin, des dispositifs assurant le déplacement des images. Afin de simplifier la structure tout en conservant un haut niveau de fiabilité, on utilise, dans un premier mode de réalisation du corrélateur, des lentilles qui sont disposées à des distances focales prédéterminées dans le système optique dudit corrélateur tandis que, dans un second mode de réalisation, on utilise des masques à phase aléatoire.