UAS-Methane: An unmanned aerial system for the remote sensing of methane flux

这一概念验证项目的目标是开发和测试一个新的综合无人机系统（UAS）遥感平台，用于测量三维甲烷浓度场和排放通量。我们的技术方法是将旋转悬停无人机与扫描开路可调谐二极管激光吸收光谱仪（TDLAS）集成在一起，并使用它来快速检索局部尺度（1米至1公里）上随时间变化的甲烷羽流浓度场。3D羽流平流的实时测量和可视化将有助于计算热点排放通量并服务于气体泄漏应用-这是一种与NERC温室气体源解析科学相关的应用，可用于一系列行业。迫切需要技术来应对这一科学和影响挑战。目前，国家人为甲烷清单和工业生命周期分析是对各种源类型的散逸性排放量外推的最佳猜测。甲烷的天然（生物）来源也很难通过测量来表征。正如2015年在巴黎举行的第21届缔约方大会（COP-21）上商定的那样，目前估计的人为甲烷清单现在必须包括通过测量进行的验证，以满足和监测雄心勃勃的2050年排放目标。基于UAS的测量为此提供了一种成熟的适当技术。无人机系统的垂直剖面、机动性和观测几何结构为地方尺度遥感应用和场地范围的监测提供了独特的采样。该提案旨在发展这样一种能力，从概念到原型，并建立在该团队的经验，在发展无人机系统为其他环境科学application.UK的专业知识和基础设施，在使用无人机系统技术的环境科学落后于一个新兴的国际社会，承诺彻底改变当地规模的过程中的几个NERC的主题（见图1）。我们在开发和飞行现场UAS测量系统的经验的基础上，开发了一种新的遥感UAS TDLAS扫描技术。该项目开发了一个新的通量概念，并解决了传感器平台集成的实际挑战。TDLAS与UAS的集成与TRL 3/4（非集成组件）相当，而我们试图用于从浓度测量中获得通量的数据遥测和层析反演算法都是概念性的（与TRL 2相当）。我们将根据TRL 5/6标准（台架测试和验证）开发和测试这种集成技术，以便在项目结束时准备好进行现场试验。总之，我们的概念是检索甲烷通量遥感无人机平台上。解决这一概念的技术是开发一个集成的UAS-TDLAS平台与扫描万向节。验证这一概念所需的证据将是一个经过验证的数据集，它使用定制的层析成像算法来反演甲烷通量的浓度测量。

The goal of this proof of concept project is to develop and test an integrated new unmanned aerial system (UAS) remote sensing platform for the measurement of 3-dimensional methane concentration fields and emission flux. Our technology approach is to integrate a rotary-hovering UAS with a scanning open-path tuneable-diode-laser absorption spectrometer (TDLAS) and use it to rapidly retrieve time-evolving methane plume concentration fields over local scales (1m to 1 km). A real-time measurement and visualisation of 3D plume advection would facilitate the calculation of hotspot emission flux and serve gas-leak applications - an application relevant to NERC greenhouse-gas source apportionment science with transferability for a range of industries. There is an urgent technological need to meet this science and impact challenge. National anthropogenic methane inventories and industrial life cycle analyses are at present a best guess of fugitive emissions extrapolated for various component source-types. Natural (biogenic) sources of methane are also poorly characterised by measurement. As agreed at the 21st Conference of the Parties (COP-21) in Paris in 2015, currently estimated anthropogenic methane inventories must now include validation by measurement to meet and monitor ambitious 2050 emissions targets. UAS-based measurement offers an appropriate technology ripe for development for this purpose. The vertical profiling, manoeuvrability, and viewing geometry of UAS offers unique sampling for local-scale remote sensing applications and site-wide monitoring. This proposal seeks to develop such a capability from concept to prototype and builds on the team's experience in development of UAS for other environmental science applications.UK expertise and infrastructure in the use of UAS technology for environmental science lags behind an emerging international community that promises to revolutionize understanding of local scale processes across several NERC themes (see Figure 1). We build on our experience in developing and flying in situ UAS measurement systems to develop a new remote sensing UAS TDLAS scanning technology. The project develops a new flux concept and addresses practical challenges in sensor-platform integration. The integration of TDLAS with UAS is commensurate with TRL 3/4 (non-integrated components), while data telemetry and the tomographic inversion algorithms we seek to use to derive flux from concentration measurements are all conceptual (commensurate with TRL 2). We will develop and test this integrated technology to TRL 5/6 criteria (bench test and validation) such that a working prototype platform may be ready for field trial at the conclusion of the project. To summarise, our concept is to retrieve methane flux by remote sensing on a UAS platform. The technology to address this concept is the development an integrated UAS-TDLAS platform with a scanning gimbal. And the proof required to validate the concept will be a validated dataset, which uses tailored tomographic algorithms to invert concentration measurements for methane flux.