Real-Time Remote Detection of Airborne Chemical Hazards—An Unmanned Aerial Vehicle (UAV) Carrying an Ion Mobility Spectrometer

Rapidly detecting and identifying chemical agents after a chemical release is crucial for a reliable assessment of imminent risks and provides the initial basis for defining an adequate level of protection for first responders. An unmanned/uncrewed aerial vehicle (UAV) equipped with gas detectors may quickly explore the contaminated area without exposing any first responders to the yet unknown threat. However, UAVs possess limitations in their capability concerning payload, operational range, and power requirements. Choosing the appropriate gas sensors for this application, thus, imposes significant technical challenges. In this work, we present a mobile ion mobility spectrometer (IMS) designed for operation with UAVs. The IMS is equipped with a dedicated closed gas loop, high-performance driver electronics, and wireless data transmission capabilities. The resulting performance of the UAV-mounted mobile IMS is characterized in the laboratory with the chemical warfare agents (CWAs) sarin (GB), tabun (GA), soman (GD), cyclosarin (GF), and sulfur mustard (HD), and further evaluated in three different field-testing scenarios using the simulation compound di(propylene glycol) methyl ether (DPM). It is thereby used to monitor the area near: 1) a point source continuously emitting small quantities of a gaseous chemical; 2) a point source suddenly releasing a limited quantity of a chemical as an aerosol; and 3) a minor contamination of a liquid chemical on the ground. The results obtained in this work enable a well-founded estimation of the capabilities and limitations of the UAV-mounted mobile IMS concerning the real-time remote detection of chemical hazards such as CWAs.