LAUSR

Abstract TCSPC technique requires that the signal should be weak with average numbers of photons in one signal period being less than 0.01 to 0.1 in order to ensure the accuracy. If the signals are stronger, the photon pile-up will lead to range walk errors. In this paper, the range walk errors of TCSPC lidar using photomultiplier tube caused by the amplitude change and distortion of reconstructed laser waveform are theoretically analyzed. A correction method for the errors under strong signal situations is proposed and validated in a laser ranging experiment. The results show that, using the correction method, range walk errors can be reduced from 183mm to 6mm for the case when the average number of photons detected is 9.6 and the distance of the target is ∼ 4.8m. The applicable returned signal domain of the TCSPC technique has been extended up to 10 photons per signal period, which has been improved by two orders of magnitude compared to the conventional weak signals.