Resolution Limit of Single-Photon LiDAR

TL;DR

This paper investigates the fundamental resolution limit of single-photon LiDAR systems, analyzing the trade-off between spatial resolution and signal quality, and deriving theoretical bounds for localization accuracy.

Contribution

It provides a theoretical framework for understanding the resolution limit of single-photon LiDAR, including new approximation techniques and MSE bounds for time delay estimation.

Findings

Theoretical bounds match simulation results

Resolution is limited by photon flux and detector array density

Derived MSE expressions predict localization accuracy

Abstract

Single-photon Light Detection and Ranging (LiDAR) systems are often equipped with an array of detectors for improved spatial resolution and sensing speed. However, given a fixed amount of flux produced by the laser transmitter across the scene, the per-pixel Signal-to-Noise Ratio (SNR) will decrease when more pixels are packed in a unit space. This presents a fundamental trade-off between the spatial resolution of the sensor array and the SNR received at each pixel. Theoretical characterization of this fundamental limit is explored. By deriving the photon arrival statistics and introducing a series of new approximation techniques, the Mean Squared Error (MSE) of the maximum-likelihood estimator of the time delay is derived. The theoretical predictions align well with simulations and real data.