Pileup effect corrections for at most two triggers synchronous single-photon LiDAR

Single-photon avalanche diode (SPAD)-based light detection and ranging (LiDAR) cannot respond to photons arriving within the SPAD's dead time. When incident flux is high, the pileup error is introduced. With the development of large-format SPAD arrays, SPAD detectors with specific working modes have emerged to balance detection efficiency and hardware resources. In this letter, considering a SPAD with a time-to-digital converter (TDC) which records at most two photon events per laser pulse cycle, we established a forward model for the photon detection histogram and proposed new pileup correction formula. The effectiveness of the proposed formula was verified through Monte Carlo (MC) simulation.