Abstract:
To acquire multidimensional characteristic information of ancient architectures, such as spatial structure, historical evolution and health status, this paper developed a hyperspectral LiDAR (HSL) system that implemented continuous spectrum wavelength selection from 550 nm to 1050 nm by an acousto-optic tunable filter (AOTF). 5 GHz/s high-speed acquisition card recorded the full waveform, including the transmitted and the echo waveforms. A two-mode step scanning strategy, including static single-point testing and zigzag scanning mode, was designed to ensure the accurate acquisition of three-dimensional spatial information. The reflectivity stability, signal-to-noise ratio (SNR), and scanning accuracy tests were conducted in an experimental environment, which indicated that our HSL system was stable and reliable. The 3D reconstruction distribution of ancient building components was presented with a single wavelength quantized voltage value, and the component material classification was conducted by a random forest (RF) classifier with hyperspectral reflectance. The results show that the system can obtain reliable 3D spatial and supercontinuous spectral information, providing multidimensional feature data for ancient architecture modelling.