Effects of Downwash from a 6-Rotor Unmanned Aerial Vehicle (UAV) on Gas Monitor Concentrations


Unmanned aerial vehicles (UAVs) are being explored by researchers to measure concentrations of gas emissions in situations where such measurements are otherwise extremely difficult to obtain, such as NO and NO2 (NOx) emissions from surface mine blasting. Recently, countries have imposed or are planning to impose surface blasting gas pollution regulations, which creates a need for an improved understanding of UAV-based gas measuring systems. The experiments detailed in this paper were performed to determine if airflow generated by the rotors, also known as downwash, unnaturally alters concentration measurements. Downwash turbulence could create locations of varying pressure, which could affect concentration. A UAV fitted with gas sensors was attached to a stand in a controlled environment containing a mixture of NOx. The gas sensor measuring points were placed at various distances on and from the UAV body to evaluate downwash effects on gas concentration. Results show that the presence of downwash turbulence causes no statistically significant changes to concentration measurements at any distance or direction from the UAV. Based on these results, it is possible to use a UAV-mounted gas monitor to measure concentrations without concern for downwash interference, provided the UAV and measuring point are entirely contained within the gas cloud.


Mining Engineering


The research was supported by the Society for Mining, Metallurgy, and Exploration (SME) Career Development Grant.

Keywords and Phrases

Air pollution; Downwash; Drone; Gas concentration; Gas sensor; NOx; UAV

International Standard Serial Number (ISSN)

2524-3462; 2524-3470

Document Type

Article - Journal

Document Version


File Type





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Publication Date

20 May 2021