Patent ID: 7164468

Claim:
A method for detection and location of smoke, characterised by the use of a biaxial lidar station comprising: transmitting a pulsed laser source of a probing beam, with the energy of 1 μJ–1 J per pulse, repetition rate of 0.5 Hz–20 kHz, and the wavelength in the range 0.2–12 μm; collecting the backscattered radiation with a telescope; suppressing of the background radiation with an optical filter having a transmittance window of 0.1–10 nm spectral width, centred at the wavelength of the emitted laser radiation; measuring the collected radiation with a photodetector; controlling a diaphragm for control of the detector aperture; controlling a beam scanning with a computer controlled unit; controlling a detector signal with an analog-to-digital converter synchronised with a laser shutter, which transforms the detector signal and sends it to a memory unit; accumulating the lidar returns resulting from the backscattering from each laser pulse in said memory unit; processing and analyzing the lidar signal and identification of eventual smoke plumes, based on a neural network algorithm, in which the neural network is simulated or implemented as a co-processor; performing overall control of the system in the following aspects: (i) analyses the messages of the signal-processing software and, if necessary, activates the alarm; (ii) controls the azimuth and elevation step motors in order to realise optimised scanning procedure with respect to the azimuth and elevation angles; (iii) if necessary, modifies the scanning procedure and other system parameters.