GeologyObserver-1: A Dual-Frequency Photon-Counting LiDAR UAV Detection System for 3-D Land and Water Mapping

Photon-counting LiDAR systems are an efficient method for nearshore bathymetry and topographic mapping. Current single-photon LiDAR systems predominantly utilize lasers with wavelengths of 1550 or 532 nm and typically have a repetition rate of less than 100 kHz, which fails to meet the integrated marine and terrestrial detection needs of remote sensing. Addressing these limitations, this study has developed a novel dual-frequency photon-counting LiDAR system that incorporates a miniaturized high-repetition-rate blue-green laser, a wide dynamic range highly sensitive photon-resolvable detector, and an embedded real-time photon data high-speed sampling and storage mechanism. This system achieves high-repetition-rate laser pulses of 1000 kHz and energy detection ranging from pico-watts to micro-watts. The bathymetric capabilities are improved to 2.5 times the Secchi disk depth, with bathymetric accuracy better than 0.2 m, ranging accuracy better than 0.1 m, and horizontal positioning accuracy better than 0.5 m. Moreover, weighing less than 8 kg, it is compatible with mainstream airborne platforms, significantly enhancing the integrated marine and terrestrial detection capabilities of remote sensing.