Full-Waveform Modeling for Time-of-Flight Measurements based on Arrival Time of Photons

TL;DR

This paper introduces a modular, highly accurate simulation model for the raw detector signals in time-of-flight LiDAR systems, enabling early system parameter prediction and reducing development costs.

Contribution

It presents a novel modular modeling approach for LiDAR signal simulation, validated with high accuracy, adaptable to various systems, and useful for early design optimization.

Findings

R-squared > 0.990 between simulated and measured signals

Good noise modeling agreement with measurements

Model aids in early prediction of LiDAR system parameters

Abstract

Modern LiDAR sensors find increasing use in safety-critical applications. Therefore, highly accurate modeling of the system's behavior under demanding environmental conditions is necessary. In this paper, we present a modular structure to accurately simulate the amplified raw detector signal of a direct time-of-flight LiDAR system for coaxial transmitter-receiver optics. Our model describes, a measurement system based on standard optical components and a detector able of converting single photons to an electrical signal. To verify the model's predictions, single-point measurements for targets of different reflectivity at defined distances were performed. Statistical analysis shows an R-squared value greater than 0.990 for simulated and measured signal amplitude levels. Noise modeling shows good accordance with the performed measurements for different target irradiance levels. The presented results have a guiding significance in the modeling of the complex signal processing chain of LiDAR systems, as it enables the prediction of key parameters of the system early in the development process. Hence, unnecessary costs by design flaws can be mitigated. The modular structure allows easy adaption for arbitrary LiDAR systems.