Three-dimensional real-time mapping of CO and CO2 concentrations in active forest burns with a UAV spectrometer

Abstract

A compact infrared absorption spectrometer is developed and integrated with a light-duty unmanned aerial vehicle (UAV) to provide high-resolution, real-time spatial mapping of species concentrations in dynamic atmospheric environments. The multi-species optical sensor is contained within a 0.5 ft³ package that is mounted to a custom fabricated quadrotor UAV. The on-board optical diagnostics record CO and CO<inf>2</inf> concentrations which are transmitted in real-time at a rate of 1.25 Hz to a remote monitoring station. The sensor results are synchronized with the UAV GPS system to generate time-histories and spatial maps. The aerial spectrometer was deployed in a series of prescribed forest burns at the UC Berkeley Blodgett Forest Research Station, where it successfully captured transient plume behavior and generated three-dimensional spatial profiles on 100 m spatial scales and altitudes up to 100 m. The measurements presented here aim to demonstrate the potential for high-resolution, UAV-borne optical sensors for atmospheric monitoring in harsh, dynamic environments, while serving as a guide for future technological improvements and applications.