Influence of Waveform Characteristics on LiDAR Ranging Accuracy and Precision.

Xiaolu Li,Duan Li,Bingwei Yang,Xinhao Xie,Lijun Xu

doi:10.3390/s18041156

Abstract

Time of flight (TOF) based light detection and ranging (LiDAR) is a technology for calculating distance between start/stop signals of time of flight. In lab-built LiDAR, two ranging systems for measuring flying time between start/stop signals include time-to-digital converter (TDC) that counts time between trigger signals and analog-to-digital converter (ADC) that processes the sampled start/stop pulses waveform for time estimation. We study the influence of waveform characteristics on range accuracy and precision of two kinds of ranging system. Comparing waveform based ranging (WR) with analog discrete return system based ranging (AR), a peak detection method (WR-PK) shows the best ranging performance because of less execution time, high ranging accuracy, and stable precision. Based on a novel statistic mathematical method maximal information coefficient (MIC), WR-PK precision has a high linear relationship with the received pulse width standard deviation. Thus keeping the received pulse width of measuring a constant distance as stable as possible can improve ranging precision.

Highlights

Time of flight (TOF) based light detection and ranging (LiDAR) is a technology for measuring the distance between the laser transmitter and the target [1,2,3]
This manuscript employs a waveform-post-processing based time discrimination algorithms (WR-Peak Discriminator (PK) method) to measure distance which shows the excellent ranging performance of accuracy and precision by comparison with the results obtained from analog discrete return system (AR results)
This paper studies the ranging performance comparison between the waveform based time discrimination methods and analog discrete return system

Summary

Introduction

Time of flight (TOF) based light detection and ranging (LiDAR) is a technology for measuring the distance between the laser transmitter and the target [1,2,3]. Combining the measured distance with the laser beam steering, a three-dimensional (3D) point cloud of the target is generated in an arbitrary Cartesian mapping system [4]. The accuracy of point cloud is governed by three main errors, caused by the direct geo-referencing of laser beam, the measured range of laser itself and the mounting and scanning geometry [5]. The error derived from the measured range of laser is a basic and crucial issue, which is directly related to the trigger signals (start/stop signals) for calculating the time of flight. The most common ways of time interval measurements are divided into two categories, including time-to-digital converter (TDC) based measurement that counts time between trigger signals and analog-to-digital converter (ADC) based measurement that estimates the time interval between start/stop signals with appropriate algorithm [6]. Since TDC based LiDAR and ADC based LiDAR are both related to the echo pulse characteristics, it is very important for two kinds of ranging systems to study the influence of waveform characteristics on range measurement accuracy and precision

Methods

Findings

Discussion

Conclusion