Vehicle-Mounted Mid-Infrared Dual-Comb Spectroscopy for On-Road Trace Gas Detection

TL;DR

This paper presents the first vehicle-mounted mid-infrared dual-comb spectroscopy system capable of continuous, mobile atmospheric trace gas detection in outdoor environments, demonstrating stable operation and successful source localization.

Contribution

It introduces a novel mobile MIR DCS system for on-road atmospheric monitoring, expanding the practical deployment of dual-comb spectroscopy in real-world outdoor settings.

Findings

Stable signal-to-noise performance during on-road operation.

Successful localization of natural-gas leakage sources.

Reconstruction of methane concentration fields around a source.

Abstract

Advances in mid-infrared (MIR) dual-comb spectroscopy (DCS) have significantly enhanced molecular detection in recent years. The capability of DCS to precisely identify and quantify atmospheric trace gases makes it attractive for field applications across the environmental, agricultural, energy, and industrial sectors. In particular, there is a growing demand for mobile and continuous gas monitoring in outdoor environments where emission sources and sinks are often episodic and spatially heterogeneous. However, the practical field-deployment of DCS on mobile platforms under realistic field conditions has remained limited. This study demonstrates for the first time a vehicle-mounted MIR DCS system that enables continuous mobile atmospheric sampling across multiple outdoor sites and road environments. The system exhibited a stable signal-to-noise performance during on-road operation, including expressway driving at speeds up to 100 km/h. Furthermore, natural-gas leakage sources were successfully located and a two-dimensional methane concentration field was reconstructed around a controlled release source. In the future, the system can be integrated into more mobile platforms, such as unmanned aerial vehicles, enabling flexible trace gas detection over urban-scale regions.