Detection of weak laser pulses by full waveform stacking

Pulse detection is a fundamental task of processing data of pulsed laser systems for extracting features of the illuminated object. Weak pulses below the threshold are discarded by classic methods and the involved information will get lost. In this paper we present an approach for detecting weak pulses from waveform laser data based on analyzing neighbourhood relations given by coplanarity constraint. Waveform stacking technique is used to improve the signal to noise ratio (SNR) of object with poor surface response by means of mutual information accumulation, thus hypotheses for planes of different slopes are generated and verified. Each signal is assessed by a likelihood value with respect to accepted hypotheses. At last signals will be classified according to likelihood values using two thresholds and visualized by the traffic-light paradigm. The presented method was applied as a low-level operation to a whole waveform cuboid of an urban area and shows promising results. Results contain detected pulses reflected from objects, which can not be predicted by the previously detected point cloud.