| 摘要 |
The emission, in a given direction, of a beam of pulsed laser radiation which has a high intensity - and is therefore potentially dangerous for people - in order to perform measurements in the atmosphere by means of analysis of the retro-reflected radiation, is performed only after the emission, in the same direction, of low- risk sampling laser radiation and subsequent verification, by means of analysis of the retro-reflected radiation caused by the sampling radiation, that there are no solid objects present in the radiation path. The advanced emission of the sampling radiation with respect to the programmed instant for emission of the radiation is determined on the basis of the principle which ensures that a person passing through the trajectory of the radiation is struck, in the least favourable scenario, only by the low-intensity peripheral - and therefore harmless - fringe of the measurement radiation beam. Figs. 2a and 2b <IMAGE> |
