A compact and lightweight mid-infrared laser absorption spectrometer has been developed as a mobile sensing platform for high-precision atmospheric methane measurements aboard small unmanned aerial vehicles (UAVs). The instrument leverages two recent innovations: a novel segmented circular multipass cell (SC-MPC) design and a power-efficient, low-noise, intermittent continuous-wave (icw) laser driving approach. A system-on-chip hardware control and data acquisition system enables energy-efficient and fully autonomous operation. The integrated spectrometer weighs 2.1 kg (including battery) and consumes 18 W of electrical power, making it ideally suited for airborne monitoring applications. Under stable laboratory conditions, the device achieves a precision (1σ) of 1.1 ppb within 1 s and 0.1 ppb CH₄ at 100 s averaging time. Detailed investigations were performed to identify and quantify the effects of various environmental factors, such as sudden changes in pressure, temperature, and mechanical vibrations, which commonly influence UAV-mounted sensors. The instrument was also deployed in two feasibility field studies: an artificial methane release experiment and a study on vertical profiles in the planetary boundary layer. In both cases, the spectrometer demonstrated its airborne capability of capturing subtle and/or sudden changes in atmospheric CH₄ mole fractions and providing real-time data at 1 s time resolution.

中文翻译：

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紧凑的QCL光谱仪，用于无人机上的移动式高精度甲烷感测

小型轻巧的中红外激光吸收光谱仪已开发成为一种移动感测平台，可用于小型无人飞行器（UAV）上的高精度大气甲烷测量。该仪器利用了两项最新的创新技术：新颖的分段圆形多通单元（SC-MPC）设计和高效，低噪声，间歇性连续波（icw）激光驱动方法。片上系统硬件控制和数据采集系统可实现节能且完全自主的操作。集成的光谱仪重2.1 千克（含电池），消耗18  W的电能，非常适合机载监测应用。下是稳定的实验室条件下，该装置实现了精度（1个σ） 在1  s内达到1.1 ppb，在100  s的平均时间内达到0.1  ppb CH ₄。进行了详细的调查，以识别和量化各种环境因素的影响，例如压力，温度和机械振动的突然变化，这些因素通常会影响安装在无人机上的传感器。该仪器还用于两项可行性现场研究：人工甲烷释放实验和行星边界层垂直剖面研究。在这两种情况下，该分光计均展示了其机载能力，可捕获大气中CH ₄摩尔分数的细微和/或突然变化，并提供1的实时数据。 的时间分辨率。