Boosting Ranging Performance of LiDAR Using Multi-Pulse Coherent Average

To boost the ranging performance (precision, detection range, and accuracy) of analog-to-digital converter-based (ADC) LiDAR, a multi-pulse coherent average (MCA) method was utilized to improve signal-to-noise ratio (SNR) and consequently enhance the ranging precision. Based on a self-developed LiDAR system, extensive simulations and experiments were performed to verify the theory analysis and demonstrate the following points. First, the MCA method can greatly enhance the root mean square (rms) ranging precision from 11.7 to 1.3 cm. Yet, it cannot improve ranging accuracy. Second, improved ranging precision depends mainly on the selection of the accumulative pulse number (APN) included in the MCA. Given the original pulse signal SNR of 39 dB, the ranging precision can be improved from 3.9 cm to less than 0.5 cm, when APN is set to 85. Third, increased APN will generally enhance ranging precision, within limits.