Unmanned aerial systems for trace gases

The combination of unmanned aerial systems (sUAS) with advances in laser spectroscopic sensors has resulted in unprecedented capabilities for atmospheric sensing. Small sUAS (also known as drones) allow for measurements around local emission sources at small spatial scales (10s-100s of meters), vertical profiling in the lowermost atmosphere (particularly <100 m near the surface), and flights into hazardous environments (e.g. fires, industrial facilities, extreme weather, volcanoes). Yet sampling at such scales and locales also create new challenges that need to be addressed in order to exploit the advantages of laser-based sensors on sUAS. The spatiotemporal sampling scales and environments of the desired sampling help to define the sensor performance attributes (precision, accuracy, drift, time response) and thereby play key roles defining instrument optomechanical design. Case studies will be used to demonstrate how the environmental attributes near a local trace gas emission source influence the measurement attributes of various sUAS laser-based sensors. Methods to quantify emission sources and map trace gas species will be reviewed, along with how choices of flight patterns also relate to sensor design, performance, and ultimate sampling goals. As more sUAS trace gas sensors are developed, significant improvements on quantifying the emissions of, and mapping of, trace gas species will be obtained. The measurements will help improve our understanding of trace gas species in air quality, climate change, meteorology, geosciences, and ecology (carbon and nitrogen emissions), among other fields.