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The performance of LiDAR with single-photon avalanche diode (SPAD) detectors can degrade seriously when a shortage of photons occurs in adverse environments. It is desirable for SPAD LiDAR to accumulate enough photons so that reliable target detection is maintained under such conditions. It is proposed in this letter to adopt random laser-emitting schemes, such as stochastic pulse position modulation (SPPM), to have more laser pulses illuminated on targets to increase reflected photons. Accordingly, at the receiver side, a novel method, namely multi-start-multi-stop (MSMS), is proposed to work with SPPM to generate histograms for further processing of target detection and ranging. Theoretical analysis and experiments show that the SPPM+MSMS LiDAR can produce, with far less integration time, signal levels comparable to that of conventional LiDAR.

Light detection and ranging (LiDAR) is considered as an essential part of the sensor package for future star technologies such as Advanced Driver Assistance Systems (ADAS) and Simultaneous Localization and Mapping (SLAM). Meanwhile, Single-Photon Avalanche Diode (SPAD) is a very attractive choice as light detectors in LiDARs because of its high sensitivity. LiDARs often need to work in adversary environments such as fog, rain, snow or haze; therefore, advanced signal processing is needed to overcome those difficulties. It is potentially very helpful if LiDAR signal processing can take into considerations of properties of SPADs used as photon detectors. In this paper, three special phenomena associated with specific properties of SPADs are described, and ways of exploiting phenomena for improving the performance of signal detection are explained. Preliminary simulation and/or experiment results are also provided to illustrate the potentials of these approaches.