Patent attributes
The invention relates to a range finding method for a target by means of a pulsed laser (4) and a device for detecting pulses backscattered by the target, which comprises a step for emitting pulses with a repetition frequency f. The detection device comprises an array of photodiodes (21) associated with integrators (22′). The method comprises steps for roughly then finely locating the target, the rough locating step comprising the following substeps:integration of a backscattered pulse, over a time window of duration F and offset by an offset Off between the instant of emission of the pulse and that of the start of said integration,with Off<1/f and F<1/f, as long as the signal is less than a first threshold, the integration steps are reiterated with a new offset Off incremented by approximately F relative to the preceding offset Off,on completion of these iterations, the target being roughly located within a distance range corresponding to the time window of duration F and offset by the offset Off designated Offg, the fine locating step is implemented, which comprises the following sub steps:integration of a backscattered pulse over a time window of duration F′ and offset by an offset Offf equal to Offg,the integration steps are reiterated with a new offset Offf of the time window incremented by an offset d relative to the preceding offset Offf, with d<F′ and Offg≦Offf≦Offg+F according to the detected signal.