Aerial Survey Robotics in Extreme Environments: Mapping Volcanic CO2 Emissions With Flocking UAVs

Abstract

We present methods for autonomous collaborative surveying of volcanic CO2 emissions using aerial robots. CO2 is a useful predictor of volcanic eruptions and an influential greenhouse gas. However, current CO2 mapping methods are hazardous and inefficient, as a result, only a small fraction of CO2 emitting volcanoes have been surveyed. We develop algorithms and a platform to measure volcanic CO2 emissions. The Dragonfly Unpiloted Aerial Vehicle (UAV) platform is capable of long-duration CO2 collection flights in harsh environments. We implement two survey algorithms on teams of Dragonfly robots and demonstrate that they effectively map gas emissions and locate the highest gas concentrations. Our experiments culminate in a successful field test of collaborative rasterization and gradient descent algorithms in a challenging real-world environment at the edge of the Valles Caldera supervolcano. Both algorithms treat multiple flocking UAVs as a distributed flexible instrument. Simultaneous sensing in multiple UAVs gives scientists greater confidence in estimates of gas concentrations and the locations of sources of those emissions. These methods are also applicable to a range of other airborne concentration mapping tasks, such as pipeline leak detection and contaminant localization.

CO2 emissions during the 2023 eruption in Reykjanes, Iceland: δ13C tracks magma degassing

“…We present here a novel approach that is similar to the 'ladder' technique used by the USGS with LI-COR CO2 sensors mounted on fixed-wing aircraft or helicopters (Gerlach et al, 1997;Werner et al, 2013) . However, we use a PP Systems SBA-5, a much a lower-cost and smaller sensor mounted on a UAV (Ericksen et al, in review;Ericksen et al, 2022). In our approach we fly one UAV equipped with a multi-GAS (same unit as used in Halldorsson and al.…”

Drone CO2 Measurements During the Tajogaite Volcanic Eruption

“…This extended flight time enables data collection during flights transecting the entire approximately 1 km wide plume. CO 2 concentrations were measured by PP Systems SBA-5 IR sensor mounted on the Dragonfly with data transmitted to the pilot in real-time (Ericksen et al, 2022). Wind speeds were measured hand-held anemometer from a high point on the ground close to the launch point and the UAS drift method (Liu et al, 2020;Galle et al, 2021).…”

“…We present a novel approach to surveying in-plume CO 2 concentrations and sample return during a major eruption using the Dragonfly UAS (Ericksen et al, 2022). The UAS transects the plume and employs an onboard infrared (IR) sensor to continuously obtain concentration readings.…”