Laser Doppler vibrometers on moving platforms: advancements, challenges, and future opportunities

Abstract

Laser Doppler Vibrometer (LDV) is a non-contact sensing technology widely used for vibration, acoustic, and wave measurements. In recent years, the deployment of LDV on moving platforms (LDVom), such as ground vehicles, robots, and drones, has enabled new solutions for remote sensing and condition monitoring of (infra)structures. LDVom leverages the mobility of manned and unmanned platforms, which offer distinct advantages in flexibility, coverage, and efficiency, but also face challenges arising from laser speckle, platform motion and vibration, and optical turbulence. This review synthesizes the technological enablers, diverse applications, unresolved challenges, and future opportunities of LDVom. The key technological enablers include tailored de-noising, signal diversity, laser head vibration compensation, and multi-point sensing. Current implementations of LDVom are predominantly vehicle-based, achieving real-world monitoring of road and railway infrastructure at near-traffic speeds, while emerging airborne implementations extend LDVom to drones and aircraft. Despite these advances, unresolved issues related to platform dynamics, target surface properties, environmental disturbances, and operational complexity continue to limit measurement quality, resolution, and reliability. Future advances in miniaturization, advanced signal diversity, multi-dimensional, multi-quantity LDV, and digital twins hold the potential to expand the capability and performance of LDVom. This review positions LDVom as an evolving and versatile technology with strong application potential across diverse domains.