alarm system and revelation of problems suitable for helicopters

摘要

Obstacle detection and warning system which in the following we shall refer to as OWS (Obstacle Warning System) consisting of a Nd:YLF laser emitter (A) pumped by laser diodes which scans the surrounding space (F) by means of an acousto-optical deflector. The radiation reflected by an obstacle is received by a silicon avalanche sensor (B); signal processing (C) provides warning and range of the obstacle detected. The obstacles which are detected are presented upon a display (D) where range is coded in terms of shades of gray or colours according to the graphic capabilities of the system in positions which correspond to the laser beam position in relation to the optical axis. The system is particularly well suited for flight by night and/or at very low altitude by a rotating wing type of aircraft and it is capable of detecting an obstacle having the dimensions of an electrical cable (3 mm section) even if the cable is not crossed by any current (and therefore is not heated due to Joule effect).