||Gas flares are an important safety and emission control device used by the petrochemical and chemical industries to dispose of large amounts of flammable hydrocarbon gases produced in various manufacturing and industrial processes. Previous work to characterize the efficiency of the flare combustion process and emissions emanating therefrom (i.e., CO, CO2, CH4, unburnt hydrocarbons, and soot) has focused on characterizing the performance of single point elevated flares using extractive sampling techniques together with sensor technology used in standard stack sampling (e.g., CMA 1983 and TCEQ 2010). More recent studies have extended the work by applying several different optical techniques including Open-Path Fourier Transform Infra-Red Spectroscopy (OPFTIR), the SKY-LOSA technique for Black Carbon (BC) emissions and passive FTIR (PFTIR) technique. Application of these techniques in previous tests have focused only on examining the performance of a non-assisted or assisted flare tip with samples collected from a single region above the flare combustion zone. The measured data were collected from a temporally and spatially varying plume with reported gas concentrations from the flare representing an averaged result. To this point, none of these techniques appear to have been applied to Multi-Point Ground Flares (MPGF) due to the sampling limitations.; Current work by Elevated Analytics, Inc. makes use of unique carbon nanotube (CNT) based sensors to measure gas concentrations of CO, CO2, CH4. These sensors are ultra-lightweight which makes them well suited for use on Unmanned Aerial Systems (UAS) to make measurements in "hard-to-reach" locations. These sensors use very fast response time, coupled with the UAS based gps data, to monitor real-time CO, CO2 and CH4 concentrations, gas temperature and relative humidity. Real-time spatial position of time resolved data provides a "time-varying" contour map of regional air quality. This feature allows the system to function as an early warning device as well. Work presented in this paper describes application of this technology to monitoring gas flare plumes using special control technology that allows the UAS to automatically track the flare plume. Testing has been accomplished using full-scale industrial flares at Zeeco's flare test facility. Results demonstrate these UAS based sensors can accurately track flare emissions that can be used to determine actual real-time flare combustion efficiency.